U.S. patent application number 15/439105 was filed with the patent office on 2017-06-08 for customized dental prosthesis for periodontal or osseointegration and related systems.
This patent application is currently assigned to Natural Dental Implants, AG. The applicant listed for this patent is Natural Dental Implants, AG. Invention is credited to Ernst-Ulrich Berndt, Jakob Sebastian Marquard, Lea Ellermeier Nesbit, Ruedger Rubbert, Hauke Schmidt-Martens.
Application Number | 20170156824 15/439105 |
Document ID | / |
Family ID | 45757388 |
Filed Date | 2017-06-08 |
United States Patent
Application |
20170156824 |
Kind Code |
A1 |
Rubbert; Ruedger ; et
al. |
June 8, 2017 |
Customized Dental Prosthesis For Periodontal or Osseointegration
and Related Systems
Abstract
Custom dental prosthesis or implants each individually designed
and manufactured to replace nonfunctional natural teeth positioned
in a jawbone of a specific pre-identified patient are provided. An
example dental prosthesis/implant includes a dental implant body
having a prosthesis interface formed therein to receive an
occlusally-facing dental prosthesis component. The prosthesis
interface has a custom three-dimensional surface shape positioned
and formed to create a form locking fit with respect to the
occlusally-facing dental prosthesis component when positioned
thereon.
Inventors: |
Rubbert; Ruedger; (Berlin,
DE) ; Berndt; Ernst-Ulrich; (Berlin, DE) ;
Marquard; Jakob Sebastian; (Berlin, DE) ;
Schmidt-Martens; Hauke; (Hamburg, DE) ; Nesbit; Lea
Ellermeier; (Dallas, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Natural Dental Implants, AG |
Berlin |
|
DE |
|
|
Assignee: |
Natural Dental Implants, AG
|
Family ID: |
45757388 |
Appl. No.: |
15/439105 |
Filed: |
February 22, 2017 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
13247843 |
Sep 28, 2011 |
|
|
|
15439105 |
|
|
|
|
12763001 |
Apr 19, 2010 |
8602780 |
|
|
13247843 |
|
|
|
|
11724261 |
Mar 15, 2007 |
7708557 |
|
|
12763001 |
|
|
|
|
11549782 |
Oct 16, 2006 |
8454362 |
|
|
11724261 |
|
|
|
|
61454450 |
Mar 18, 2011 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61C 8/0077 20130101;
A61C 13/0013 20130101; A61C 13/0006 20130101; A61C 19/10 20130101;
A61L 27/08 20130101; A61L 27/3804 20130101; A61C 8/0015 20130101;
A61L 27/025 20130101; A61C 8/0075 20130101; A61L 27/16 20130101;
A61C 8/0068 20130101; A61C 8/0013 20130101; A61C 8/0009 20130101;
A61C 8/0018 20130101; A61C 13/0001 20130101; A61C 5/007 20130101;
A61C 13/0022 20130101; A61C 13/082 20130101; A61L 2430/12 20130101;
A61L 27/3865 20130101; A61C 8/0012 20130101; A61C 13/0028 20130101;
A61C 8/0006 20130101; A61C 13/0004 20130101; A61C 5/30 20170201;
A61C 13/0019 20130101; A61C 8/0036 20130101; A61C 19/063 20130101;
A61C 13/0018 20130101; A61C 9/0046 20130101 |
International
Class: |
A61C 8/00 20060101
A61C008/00; A61L 27/16 20060101 A61L027/16; A61C 13/107 20060101
A61C013/107; A61C 13/00 20060101 A61C013/00; A61C 19/10 20060101
A61C019/10 |
Claims
1. A dental prosthesis to replace a specific natural tooth of a
pre-identified patient, the dental prosthesis to be integrated into
a receiving jawbone cavity structure of the pre-identified patient
corresponding to the specific natural tooth, the dental prosthesis
being a finished manufactured product prior to its insertion into
the receiving jawbone cavity structure, wherein the dental
prosthesis comprises: a root body and an occlusal-facing body,
wherein the root body is configured to be positioned in and
substantially integrated into and adopted by at least one of the
following: a jawbone structure of the pre-identified patient and a
periodontal ligament structure of the pre-identified patient,
defining the receiving jawbone cavity structure, wherein the root
body comprises a spatial custom root surface shape dimensionally
correlated to a corresponding spatial surface shape of at least one
of the following: a root portion of the specific natural tooth of
the pre-identified patient and the receiving jawbone cavity
structure, and wherein the root body and the occlusal-facing body
comprise a plurality of layer builds of a rapid prototyping
material.
2. A dental prosthesis as defined in claim 1, wherein the root body
is configured to be positioned in and substantially integrated into
and adopted by the jawbone structure of the pre-identified
patient.
3. A dental prosthesis as defined in claim 1, wherein the root body
is configured to be positioned in and substantially integrated into
and adopted by the periodontal ligament structure of the
pre-identified patient.
4. A dental prosthesis as defined in claim 1, wherein the spatial
custom root surface shape dimensionally matches the corresponding
spatial surface shape of the root portion of the specific natural
tooth.
5. A dental prosthesis as defined in claim 1, wherein the spatial
custom root surface shape dimensionally matches an oversized
representation of the corresponding spatial surface shape of the
root portion of the specific natural tooth.
6. A dental prosthesis as defined in claim 1, wherein the spatial
custom root surface shape dimensionally matches an undersized
representation of the corresponding spatial surface shape of the
root portion of the specific natural tooth.
7. A dental prosthesis as defined in claim 1, wherein the spatial
custom root surface shape dimensionally matches the corresponding
spatial surface shape of the receiving jawbone cavity
structure.
8. A dental prosthesis as defined in claim 1, wherein a first
plurality of layer builds of the plurality of layer builds
comprises a first rapid prototyping material, and a second
plurality of layer builds of the plurality of layer builds
comprises a second rapid prototyping material.
9. A dental prosthesis as defined in claim 8, wherein the first
rapid prototyping material has a first hardness that is different
when compared to a second hardness of the second rapid prototyping
material.
10. A dental prosthesis as defined in claim 8, wherein the first
rapid prototyping material provides a first stiffness that is
different when compared to a second stiffness provided by the
second rapid prototyping material.
11. A dental prosthesis as defined in claim 8, wherein the first
rapid prototyping material comprises a first set of substances that
is different when compared to a second set of substances comprised
in second rapid prototyping material.
12. A dental prosthesis as defined in claim 8, wherein the first
rapid prototyping material provides a first set of biological
properties that is different when compared to a second set of
biological properties provided by the second rapid prototyping
material.
13. A dental prosthesis as defined in claim 1, wherein the rapid
prototyping material comprises hardened powder material.
14. A dental prosthesis as defined in claim 1, wherein the rapid
prototyping material is a powder in a pre-manufacturing stage.
15. A dental prosthesis as defined in claim 1, wherein the rapid
prototyping material comprises a photopolymer material.
16. A dental prosthesis as defined in claim 1, wherein the
occlusal-facing body is a crown.
17. A dental prosthesis as defined in claim 1, wherein the
occlusal-facing body is an abutment.
18. A dental prosthesis as defined in claim 1, wherein the
occlusal-facing body comprises an interface to receive a crown.
19. A dental prosthesis as defined in claim 1, wherein the rapid
prototyping material is configured for selective laser sintering in
its pre-manufacturing stage.
20. A dental system for oral implant-based rehabilitation of tooth
loss, the system comprising: a virtual interface model of an
interface portion of a dental implant to receive a dental crown, a
virtual root model of a custom root portion of the dental implant,
a workpiece comprising a plurality of layer builds of a rapid
prototyping material, wherein the workpiece comprises a first
three-dimensional surface shape dimensionally correlated to a
corresponding virtual surface shape of the virtual interface model,
and wherein the workpiece comprises a second three-dimensional
surface shape dimensionally correlated to a corresponding virtual
surface shape of the virtual root model.
21. A dental system as defined in claim 20, wherein the rapid
prototyping material comprises hardened powder material.
22. A dental system as defined in claim 20, wherein the rapid
prototyping material comprises a photopolymer material.
23. A dental system as defined in claim 20, wherein the rapid
prototyping material is a powder in a pre-manufacturing stage.
24. A dental system as defined in claim 20, wherein the workpiece
is the dental implant, and wherein the dental implant comprises the
interface portion to receive the dental crown and the custom root
portion.
25. A dental system as defined in claim 20, the system further
comprising: a combined numerical description correlating to a
virtual three-dimensional surface shape of the dental implant, the
combined numerical description comprising a virtual
three-dimensional surface shape correlating to the virtual
interface model and a virtual three-dimensional surface shape
correlating to the virtual root model.
26. A dental system as defined in claim 25, wherein the plurality
of layer builds are stacked in a third dimension to form the
workpiece as a solid body, and each layer build comprises an edge
dimensionally matching a corresponding numerical description
correlating to a three-dimensional surface shape of the dental
implant.
27. A dental system as defined in claim 20, wherein the workpiece
is a sample and the rapid prototyping material comprises a resin
material configured for lost-sample casting.
28. A dental system as defined in claim 20, wherein the workpiece
is a sample and the rapid prototyping material comprises a wax
material configured for lost-sample casting.
29. A dental system as defined in claim 20, wherein the workpiece
is a green body, the rapid prototyping material is configured for
sintering, and the rapid prototyping material is configured to
receive its final material properties by sintering.
30. A dental system as defined in claim 20, wherein the workpiece
is the dental implant, and the rapid prototyping material is
configured for selective laser sintering in its pre-manufacturing
stage.
31. A rapid prototyping method to fabricate a dental prosthesis to
replace a specific natural tooth of a pre-identified patient, the
dental prosthesis to be integrated into a receiving jawbone cavity
structure of the pre-identified patient corresponding to the
specific natural tooth, the dental prosthesis being a finished
manufactured product prior to its insertion into the receiving
jawbone cavity structure, the dental prosthesis comprising a custom
shaped root body and an occlusal-facing body, the method comprising
the steps of: receiving a first set of digital data representing a
virtual root model; receiving a second set of digital data
representing a virtual interface model; and utilizing a
layer-by-layer process to form a workpiece from a rapid prototype
material responsive to the first set of digital data and responsive
to the second set of digital data, wherein the virtual root model
represents the custom shaped root body of the dental prosthesis,
wherein the virtual interface model represents an interface of the
occlusal-facing body to receive a dental crown, wherein a first
three-dimensional surface shape of the workpiece dimensionally
correlates to a corresponding three-dimensional surface shape of
the virtual interface model, and wherein a second three-dimensional
surface shape of the workpiece dimensionally correlates to a
corresponding three-dimensional surface shape of the virtual root
model.
32. A rapid prototyping method as defined in claim 31, wherein the
layer-by-layer process forms a plurality of layer builds, the
plurality of layer builds being solidly stacked to form the
workpiece.
33. A rapid prototyping method as defined in claim 31, wherein the
layer-by-layer process employs a controlled laser beam to harden
the rapid prototype material.
34. A rapid prototyping method as defined in claim 31, wherein the
rapid prototype material comprises a powder.
35. A rapid prototyping method as defined in claim 31, wherein the
workpiece is the dental prosthesis.
36. A rapid prototyping method as defined in claim 31, wherein the
workpiece is formed from greater than one rapid prototyping
material.
37. A rapid prototyping method as defined in claim 31, wherein the
first three-dimensional surface shape of the workpiece
dimensionally matches the corresponding three-dimensional surface
shape of the virtual interface model.
38. A rapid prototyping method as defined in claim 31, wherein the
second three-dimensional surface shape of the workpiece
dimensionally matches the corresponding three-dimensional surface
shape of the virtual root model.
39. A rapid prototyping method as defined in claim 35, wherein the
custom shaped root body is configured to be positioned in and
substantially integrated into and adopted by natural hard or soft
tissue of the receiving jawbone cavity structure of the
pre-identified patient.
40. A rapid prototyping method as defined in claim 31, wherein the
method further comprises the step of: combining the virtual
interface model and the virtual root model to form a virtual
three-dimensional solid object, the virtual three-dimensional solid
object to comprise an unambiguous numerical description of a
virtual surface of the virtual three-dimensional solid object, the
unambiguous numerical description showing no holes and identifying
an inside and an outside of the virtual surface.
41. A rapid prototyping method as defined in claim 31, wherein the
method further comprising the step of: transferring the first set
of digital data and the second set of digital data by a computer
network.
42. A rapid prototyping method as defined in claim 31, wherein the
layer-by-layer process is employed at a dentist's office.
43. A rapid prototyping method as defined in claim 31, wherein the
layer-by-layer process is employed in a laboratory.
44. A rapid prototyping method as defined in claim 31, wherein the
layer-by-layer process deposits the rapid prototyping material
responsive to the first set of digital data and to the second set
of digital data.
45. A rapid prototyping method as defined in claim 32, wherein each
layer build constitutes a two-dimensional cross section of the
workpiece having an edge defined by the first set of digital data
or by the second set of digital data.
46. A rapid prototyping method as defined in claim 32, wherein the
plurality of layer builds are solidly stacked in a third dimension
to form the workpiece.
47. A rapid prototyping method as defined in claim 31, wherein the
layer-by-layer process employs a selective laser sintering
process.
48. A rapid prototyping method as defined in claim 31, wherein the
workpiece is a green body, and the method further comprises the
step of: sintering the workpiece.
49. A rapid prototyping method as defined in claim 31, wherein the
workpiece is a sample body, and the method further comprises the
step of: lost-sample casting.
50. A rapid prototyping method as defined in claim 49, wherein the
rapid prototyping material comprises a wax or resin material
configured for lost-sample casting.
Description
RELATED APPLICATIONS
[0001] This patent application is a non-provisional continuation
application and claims priority to and the benefit of now-pending
U.S. patent application Ser. No. 13/247,843, filed on Sep. 28,
2011, which itself claims priority to and the benefit of U.S.
Patent Application No. 61/454,450 filed on Mar. 18, 2011, and which
is a continuation-in-part of and claims priority to and the benefit
of U.S. patent application Ser. No. 12/763,001, filed Apr. 19,
2010, now U.S. Pat. No. 8,602,780, and is a continuation-in-part of
and claims priority to and the benefit of U.S. patent application
Ser. No. 11/724,261, filed Mar. 15, 2007, now U.S. Pat. No.
7,708,557, and is a continuation-in-part of U.S. patent application
Ser. No. 11/549,782 filed on Oct. 16, 2006, now U.S. Pat. No.
8,454,362, each incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates generally to the field of dentistry,
and more particularly to the field of dental restorations, implants
and prostheses. The invention further relates to computer assisted
and conventional systems and methods for designing and
manufacturing such custom dental prosthesis.
[0004] 2. Description of Related Art
[0005] Human teeth serve a variety of functions. Not only are they
important for chewing food, but they also necessary to properly
pronounce certain consonants, especially fizzle- and S-sounds.
Furthermore, teeth play a major role in our personal appearance.
While, healthy and well aligned teeth are an ideal of beauty and
appear as a cosmetic sign of youth and success.
[0006] Although various preventive measures, like frequent tooth
brushing and flossing, and drinking fluoridized or iodized water
are widely accepted and used, the great majority of people are
sooner or later challenged with dental fillings, restorations
implants, and/or prostheses.
[0007] A major goal in dentistry is to postpone loss of teeth as
long as possible. Another goal is certainly to provide comfortable
prostheses with a broad scope/indication and a long lasting
life-time.
[0008] Generally, the number of available restorative and
prosthetic options is limited. Typically fillings, inlays, and
crowns are used if the root and its embedding periodontal structure
are healthy, and sufficient as support for such restorative partial
prostheses. Traditionally, if the original tooth can no longer be
used; the use of bridges or non-customized osseointegrated implants
is indicated. In this context, several negative aspects are to be
endured. In order to provide the support structure for a bridge,
adjacent teeth are ground, and healthy enamel is partially
destroyed. Osseointegrated implants are drastically invasive and
the gingiva-implant interface is often the cause of chronic local
infection. Additionally, all the aforementioned restorative and
prosthetic options have a limited average lifetime. Removable
dentures are certainly the final prosthetic option.
[0009] When a tooth is partially damaged, either by caries or
mechanical impact, the missing portion should in most cases be
replaced. As long as a tooth provides enough structural strength to
support a prosthesis, for example, an inlay or a crown, this will
typically be the preferred solution. However, if the loss of tooth
substance is severe, this may not be applicable. In these cases, a
bridge can be applied, enduring the aforementioned negative
consequences. Another option is to replace the tooth with an
implant.
[0010] There are many methods or options for replacing missing
teeth. Off-the-shelf or pre-shaped osseointegrated dental implants
are one of the options. Osseointegration means the direct contact
of the implant surface with the bone without a fibrous connective
tissue interface (natural teeth are typically not in direct contact
with the bone, but are connected to the bone by ligaments). The use
of such dental implants includes a wide variety of implant designs
and materials, use of implants in different locations in the mouth
and use of a variety of surgical protocols.
[0011] Endosteal implants are placed into the bone, like natural
tooth roots. They can provide an anchor for one or more artificial
teeth. They are the most commonly used type of implants. There are
various types of endosteal implants, for example, screws,
cylinders, cones, plates and blades. The generic screw, cylinder
and cone types of implants are sometimes called "root-form" type.
Such generic root-form implants that replace a single tooth
generally consist of three parts, the actual implant-root for
osseointegration, an abutment and the artificial crown. The
interfaces between the three aforementioned parts are critical in
respect to the sealing quality between said three parts. Bacterial
infections can be caused if the sealing is compromised in regards
to its short, mid and long-term stability.
[0012] Sometimes implant designs that actually consolidate two of
said three parts, for example, the implant-root to be
osseointegrated and the abutment, are referred to as one-piece
implants.
[0013] Such three-part implant designs have a first sub-gingival
joint between the implant screw and the abutment. The first joint
is in its height placed adjacent to the bone crest of the jaw of
the implant-receiving patient. The second joint is placed iso- or
supra-gingival, which means on the same vertical height of the
mouth facing surface of the gingiva or beyond the trans-gingival
portion of the overall implant design. The first joint between the
implant screw and abutment is especially under the static and
dynamic stress of mastication forces, and is exposed as an area
where bacteria may congregate, causing a chronically infection.
[0014] Contrary hereto, the term "one-piece" implant as used
hereinafter is meant to refer to the integration of all three
parts: the implant root, the abutment, and the crown. The term
"immediate placing" of an implant is used if the integration of the
implant into the bone occurs a short term after the extraction of a
tooth. If such implants have a reasonable initial contact stability
with the bone directly after being inserted, the so called primary
stability, then such implants are called "immediately loaded",
which means that the osseo-integrative stability, the so called
secondary stability, does not need to be developed before
performing the following process steps: making an impression of the
abutment part of the implant in conjunction with the gingiva and
the adjacent teeth situation, then fabricating the crown,
implementing the crown, and actually allowing the patient to use
the implant for mastication.
[0015] Subperiosteal implants are implants that are placed over the
bone in cases where the bone has atrophied and jaw structure is
limited. Subperiosteal implants are customized metal frameworks,
providing the equivalent of multiple tooth roots. They can be
applied in a limited area or in the entire mouth. After
application, natural tissue membrane or bone will grow back around
the implant, thus providing more stability. Posts protrude through
the gum to hold the prosthesis.
[0016] Traditionally, osseointegrated dental implants are placed in
bone and covered by mucosa during the immediate post-operative
healing period. At four to eight months, a second surgical
procedure is performed to expose the implant so it may be loaded
with various types of dental crowns. In recent years, immediate
implant placement following tooth extraction and immediate crown
loading after surgical placement has become more common.
[0017] Generic ceramic dental implants are available made from
yttrium-stabilized zirconia ceramics. Although such ceramic
materials are due to its internal crystal structure and mechanisms
able to suppress micro-cracks, it has been reported that in the
moist-warm environment of the human body the long term stability of
yttrium-stabilized zirconia ceramics is compromised to the extent
that respective dental implants cannot be considered fracture-safe
for the life-time expectations established in the industry.
[0018] However, the success rate and the in-vivo life time of
osseointegrated dental implants are limited, and the surgical
procedure is heavily invasive, because the bone needs to be drilled
or ground in order to be adapted to the shape of the non-customized
implants. Furthermore, osseointegrated implants are a limiting
factor in a later orthodontic treatment. Problems relating to nerve
transposition, osseous grafting, ridge augmentation, and sinus
augmentation of osseointegrated dental implants, and/or to tissue
health adjacent to dental implants have also been reported.
Patients often complain about chronically infected periodontal
structure caused by osseointegrated implants.
[0019] In cases where a tooth is not severely damaged, and would be
ready to receive a partial restoration, but an intra-oral repair is
impossible due to access problems, or a reverse root canal
treatment is required, an alternative method is the intentional
re-implantation. The tooth is extracted, repaired, and
re-integrated into the existing periodontal structure of a dental
patient. Nuzzolese et al. wrote in the Journal of Contemporary
Dental Practice, Volume 5, No. 3, Aug. 15, 2004: "It is well known
dental reimplantation is indicated following traumatic avulsion by
the preservation of cellular vitality in the periodontal ligament
and under conditions of asepsis. The rate of endodontic success at
five years reported in the literature ranges between 70% and 91%.
However, intentional dental reimplantation is an effective strategy
for the treatment of teeth that would be difficult, if not
impossible, to treat using traditional root canal therapy.
Different prognoses exist for intentional dental reimplantation and
trauma-related reimplantation. This is due to such important
variables such as the level of cellular vitality in the periodontal
ligament; the degree of trauma to surrounding tissues, and the
degree of asepsis when a tooth is removed. Surgical extraction is
more favorable in this regard compared to a traumatic avulsion
scenario." Although this method is not yet widely used, the
reported success rates are noteworthy. Reported are also autogenous
and allogenic transplantation of a healthy natural tooth into the
extraction socket for parodontal/periodontal integration. A
disadvantage relating to all such techniques is certainly that the
specific tooth to be reimplanted or transplanted still needs an
overall reasonable condition and prognosis to justify an
intentional re-implantation and that only certain root and root
canal deficiencies can be repaired this way.
[0020] Various publications reporting that the prognosis of
intentional reimplanted or transplanted teeth is significantly
better than the reimplantation after a traumatic extraction, since
the extraction is surgically controlled and relatively aseptic
techniques are utilized. Spouge writes in his Oral Pathology,
Mosby, Saint Louis 1973; "The majority of reimplantations however
are clinically successful, and the teeth are retained firmly in the
socket for the appropriate 5 year period. However, despite the
apparent success, most of them show localized ankylosis and gross
resorption of the root at the end of this time. The fibrous
attachment that develops in the new periodontal ligament area often
involves the formation of an immature type of connective tissue
whose fibers remain tangential to the root surface rather than
becoming physiologically oriented. There is experimental evidence
to suggest that formation of a physiologic periodontium is more
easily achieved in condition where the viability of the original
periodontal ligament is maintained . . . In keeping with this, the
prognosis for clinical success in a reimplanted tooth fall rapidly
if is have been completely dislocated from its socket for more than
24 hours." Wong suggests in Quintessence International, Vol. 33,
No. 2, 2002 a surgical "exarticulation" method, where the removal
of the tooth from its socket is achieved "(after the incision of
the crestal periodontal ligament fibers with micro-blades) with a
combination of luxation and gentle, rotary, reciprocating
movements" in order to minimize physical trauma to the excising
periodontium. Goerig et al. recommends in Quintessence
International, Vol. 19, No. 8, 1988 a sectioning procedure where a
molar tooth is cut in half dividing the roots in order to minimize
the damage of the existing periodontal ligament. The Ogram System
(www.ogramsystem.com) provides a tooth removal protocol promising
no or very little trauma of the surrounding tissue.
[0021] EI-Bialy et al. from the University of Alberta, Canada
report the stimulation of jaw growth and tissue healing by directly
applying ultrasound vibes to the tooth of interest. In this context
it is known to those skilled in the art that the alternating "load"
of dental structures in patients' day-to-day use of their dentition
activates healing processes while a protection against or the
avoidance of such alternating load causes resorption of roots, bone
and soft tissue.
[0022] U.S. Pat. No. 5,562,450 references as prior art the German
application DE 27 29 969 A1, which is incorporated herein by
reference in its entirety, describing the osseintegration of an
implant that is substantially a copy of an extracted human tooth
fabricated by a process involving copy milling. In order to be
successfully osseointegrated the connective tissue (e.g., ligament)
remaining in the extraction socket needs to be removed by being
scraped out or curetted. The '450 patent recognizes the need to
create a compression pressure between the bone and the implant in
order to reach reasonable primary stability of the implant and
teaches therefore to dimensionally enlarge the anatomical shape of
the implant over the extracted tooth to fill the extraction
socket.
[0023] Rubbert and Berndt reference in the article "Topologically
Structured Surfaces and Coating Treatments for Periodontal and
Osseo-Integration" published on Apr. 7, 2009, which is incorporated
herein by reference in its entirety, various aspects of surface
condition and treatments of dental implants and prostheses.
[0024] U.S. Pat. No. 6,099,313 discloses a dental implant for
osseointegration having a bone-contact section which is root-shaped
with an apical extension and an abutment described as a build-up
section for fastening a crown.
[0025] All such restorative and prosthetic options and
methodologies are deficient--being heavily invasive and/or limited
in their respective scope. There has not been recognition, until
now by the inventors, of the need for a product, systems, and
methods related to the integration of dental prosthesis such as
artificial tooth, bridges, or segments of the dentition that
includes (a) custom-shaped root structures to be osseointegrated as
one piece, (b) custom-made positioning and fixation splints for
achieving primary stability, and (c) even more beneficial, parts to
be integrated into the existing periodontal structure of an
individual patient, having the desirable broad scope and reduced
invasive requirements. There is also no prior recognition of
fabricating the root-shaped custom portions of the prosthesis based
on anatomical imaging data prior to the extraction of the tooth or
of the teeth of interest or directly of the alveolar situation.
[0026] In addition, the inventors disclose the use of advanced
ceramic materials, manufacturing technologies to increase the
density of ceramic materials to its theoretical degree to be
considered fracture-safe for use as dental implants or prostheses,
metal-ceramic diffusion bonding technologies to overcome bacterial
issues developing on the sub-gingival joints of traditional 3-part
implant designs, and tissue engineering methods for
osseo-integration and perio-type integration to enhance the
clinical integration of prostheses designed and manufactured
according to the inventions disclosed herein as further
advantageous embodiments not previously recognized until now.
[0027] The product, and related systems and methods provided by
embodiments of the present invention or inventions comprise several
independent inventive features providing substantial improvements
to prior art. The greatest benefit will be achieved for dental
treatments--especially for patients requiring tooth
replacement.
SUMMARY OF THE INVENTION
[0028] In view of the foregoing, various embodiments of the present
invention beneficially provide customized dental prosthesis and
implants based on a process or processes that include copying a
significant portion of the original root geometry of a human tooth,
to be integrated after extraction of the original tooth either in
the existing biological cell structure of the periodontal ligament
or as one piece into the embedding bone structure of the respective
jaw. In an embodiment, primary stability is favorably achieved by a
custom made splint that connects the prosthesis with the adjacent
tooth or teeth or other dental structures like existing implants,
bridges and the like. According to various embodiments of the
present invention, an artificial root of the prosthesis or implant
can be osseointegrated--embedded into the natural extraction
cavity. According to various embodiments of the present invention,
the principle of the natural mechanism of holding the teeth in the
jaw structure of a dental patient is maintained and preserved,
whereby a customized dental prosthesis is integrated into, healed
in, and at least partially adopted by the fibrous connective tissue
interface of the anatomical structure of an individual patient that
is naturally holding the tooth.
[0029] The concept of periodontal integration of an artificial
tooth uses the existing human periodontal ligament for integration
and is certainly less invasive than the integration of
osseointegrated implants. The concept of integrating a one-piece
prosthesis that includes a root-shape part, an abutment and a crown
combines the two clinical episodes of integrating the root-shaped
part and adapting the crown into one clinical event. Even if such
one-piece prosthesis would include an assembly of two or more
parts, the assembly would be fabricated in the controlled
environment of a dental laboratory or an industrial fabrication. As
a result, the quality of the interface sealing between such parts
can be expected to be of higher quality as produced in the mouth of
the patient. This would reduce the infection rate so that the
success rate of the one-piece prosthesis according to an embodiment
of the invention would be higher as achieved with implementations
according to the prior art. The concept of a splint that is custom
made in the laboratory in advance serves two purposes: the correct
positioning of the prosthesis, and the achievement of reasonable
primary stability. The concept of using in-vivo imaging data in
order to design and fabricate the prosthesis prior to the
extraction of the teeth of interest enables a laboratory lead time
prior to the invasive clinical event. The concept of using data to
design a root-shaped portion or portions of the prosthesis not
actually of the tooth or teeth extracted or to be extracted, but of
the anatomical alveolar structure, allows the prosthesis to adapt
to the post-extraction or even post-surgical--in case of, for
example, surgical extensions to the extraction socket--shape of the
alveolar situation.
[0030] Any combination of the aforementioned concepts of the
invention can be used in embodiments of efficient and/or
less-invasive clinical methods according to the invention. One of
such clinical methods, for example, includes the immediate
placement of a one-piece prosthesis--allowing immediate loading. In
another embodiment, these concepts can be combined with methods of
ultrasonic or other vibrations applied to the prosthesis or
adjacent tooth/teeth after placement in order stimulate bone and
tissue healing. In another embodiment, the extraction of the tooth
might be performed using ultrasonic or other vibrations applied to
the tooth of interest to facilitate the extraction.
[0031] All such methods can be also favorably combined with
laboratory methods according to the invention. One of such
laboratory methods might be the coating of the root portion of the
prosthesis with engineered tissue that is grown in the laboratory
from autologous tissue, bone or root material samples of the
patient of interest. Alternatively to the aforementioned use of
autologous material, human allogenic bone, root or tissue material
can be used. Alternatively to the use of human bio material, tooth,
bone or tissue material of animals, for example, bovine or even
synthetic materials can be used for the process step of tissue
engineering. Tissue engineering includes the use of a combination
of cells, engineering materials, and suitable biochemical factors
to improve or replace biological functions. In the context of
certain embodiments of the invention disclosed herein, this would
include the growth of soft tissue or bone structures in a
controlled laboratory environment.
[0032] The term regenerative medicine is often used synonymously
with tissue engineering, although those involved in regenerative
medicine place more emphasis on the use of stem cells to produce
tissues. This is an additional approach that can be favorably
combined with other specific embodiments of the invention disclosed
herein.
[0033] The various embodiments of this invention described herein
are not only substitutive but additive to the available options in
the field of restorative and prosthetic dentistry with the result
that in most cases the need to use removable dentures will be
significantly postponed.
[0034] In this context, embodiments of the invention described
herein relate to fabricating customized segments of the dentition,
single teeth, roots and crowns or parts of those. The artificial
reproduction of the original root will be inserted into the
alveolus, the natural cavity of the root of the tooth to be
replaced. It will either be adopted by the periodontal ligament of
the patient or osseointegrated if the periodontal ligament is no
longer functional. The shape of the root can be a substantial copy
of the root to be replaced or may be intentionally smaller, for
example, to compensate for measurement or manufacturing tolerances
or inaccuracies. The shape of such roots may alternatively be a
direct copy of the root to be replaced, or it may be directly
adapted to the alveolar situation, or any combination thereof. In
certain cases it is advantageous to modify the shape to be
integrated. For instance, it may be appropriate to conjoin the two
or three roots of a molar to gain additional stability or enable
the manufacturing of such. Also, strongly bent root tips may be
reduced or left away in order to ease the insertion of the
prosthesis. In cases of root resorption, it may be appropriate to
re-establish a shape close to the estimated shape of the original
shape of the root before the resorption clinically occurred. Even
imaging data of an earlier clinical situation or imaging data of
mirrored or un-mirrored data of the same or a similar shaped root
of the same or the other (right-to-left, left-to-right) side of the
jaw or of an opponent jaw of the patient may be favorably used in
this context. It may be additionally possible to consider and use
generic (averaged) root shapes in the process designing the target
shape of the prosthesis. The extraction socket may be enlarged to
accommodate for a bigger or different root shape compared to the
extracted root shape.
[0035] Various embodiments of the present invention avoid or
postpone the need of or for conventional heavily invasive implants
for a significant time by using at first the natural periodontal
structure as long as possible and afterwards by customized
osseointegrated artificial roots or teeth. No such approach in
dentistry based on design and manufacture of customized teeth
including the root, or only roots suitable to be used in
conjunction with off-the-shelf or customized components (typically
for the visible part like veneers or complete crowns) used in the
field of implantology for an individual patient, and design and
manufacture of such customized tooth, has been proposed to date.
The implants widely used in dental treatment today are
off-the-shelf products. Because teeth have to fit properly for
comfort and healing after surgery in the periodontal ligament of a
patient, some commonly used implants do not constitute an optimal
replacement.
[0036] The shape design of mass-produced implants shows a
standardized joint between the implant and the crown portion. While
the crown is usually custom-shaped to the adjacent and opposite
teeth, the implant is not. Therefore, the joint between such
traditional crowns and implants is non-customized. Such joints are
usually shaped with standardized cylindrical, hexagonal, and
conical shape portions. In order to try to obtain a positive lock
between the implant and the crown, numerous standard form joints
are manufactured in order to try to cover a majority of the
possible crown designs. This, however, results in significant
additional manufacturing costs and difficulties in inventory
management. Alternatively, a smaller number of "standard" designs
are manufactured designed to cover most cases. Although the smaller
number helps reduce inventory management problems and manufacturing
costs, it has been found too often to lead to inadequate joint
connections and in an increased number of collisions between
components, as the clinician is often provided an improperly
fitting connection. That is, the joint having a smaller footprint
than ideal is often employed in order to allow for adjustments due
to the inadequate connection. Recognized, therefore, by the
inventors is the need for a custom joint which can provide a good
positive lock between the implant and the crown/intermediate
abutment, and which can maximize the "footprint" between the
connecting pieces.
[0037] Accordingly, various embodiments of the present invention
provide dental implant apparatus and methods of manufacturing or
otherwise providing a custom prosthesis interface having a
three-dimensional surface shape positioned and formed to create a
form locking fit with respect to the crown/abutment and the implant
body, which can maximize or at least significantly increase the
footprint of the locking fit, which can reduce and/or eliminate
collisions between manufactured components, and which allows
individualized stocking--eliminating the need to manufacture
multiple potential versions of the joint.
[0038] For example, a dental implant to replace a nonfunctional
natural tooth positioned in a jawbone of a specific pre-identified
patient according to an embodiment of the present invention can
include a dental implant body having a prosthesis interface formed
therein to receive an occlusally-facing dental prosthesis
component. The prosthesis interface has a three-dimensional, e.g.,
asymmetrically contoured, surface shape positioned and formed to
create a form locking fit with respect to the occlusally-facing
dental prosthesis component when positioned thereon. The prosthesis
interface also has an asymmetrically contoured outward facing edge
having a shape correlated to a shape of a gum line of the specific
pre-identified patient. The three-dimensional surface shape of the
prosthesis interface is also substantially asymmetrically shaped
and substantially devoid of concentric convolutionally shaped
segments with respect to a longitudinally extending axis of the
dental implant.
[0039] According to this exemplary configuration, the dental
implant body includes a root body portion having an
occlusally-facing surface, a lingual-facing side portion, a
labial-facing side portion, and a pair of proximal-facing side
portions. The three-dimensional surface shape of the prosthesis
interface includes a substantial asymmetric positive raising
extending from the dental implant body. The asymmetric positive
rising has a first rising contour extending from portions of the
occlusal facing surface of the root body portion adjacent a center
of the lingual-facing side portion and a second rising contour
extending from portions of the occlusal facing surface of the root
body portion adjacent a center of the labial-facing side, with the
second rising contour being substantially different than the first
raising contour when viewed along a cross-section of the dental
implant extending between the lingual-facing side portion and
labial-facing side portion and visa versa.
[0040] According to another embodiment of the present invention,
the dental implant can include a dental implant body having a
prosthesis interface having a three-dimensional surface shape
positioned and formed to create a form locking fit with respect to
the occlusally-facing dental prosthesis component when positioned
thereon, whereby the prosthesis interface also has an
asymmetrically contoured outward facing edge extending along
labial-facing, lingual-facing, and first and second proximal-facing
portions of the dental implant body. According to this exemplary
configuration, the asymmetrically contoured outward facing edge
follows a gum line of the specific pre-identified patient
surrounding the dental implant body when the dental implant body is
operably positioned within the jaw bone of the pre-identified
patient. The outward facing edge can be configured such that each
of a plurality of spaced apart points located along an extent of a
proximal-facing portion of the asymmetrically contoured
circumferential outward facing edge asymmetrically vary in axial
distance from a common reference point located along a
longitudinally extending axis of the dental implant body. According
to this exemplary configuration, each of the plurality of spaced
apart points located along the extent of the proximal-facing
portion of the asymmetrically contoured circumferential outward
facing edge asymmetrically vary in both radial distance from the
common reference point located along the longitudinally extending
axis of the dental implant body and in the axial distance from the
common reference point. Similar asymmetric variations can exist on
the lingual and labial-facing portions.
[0041] According to another embodiment of the present invention,
the dental implant can include a dental implant body having a
prosthesis interface formed therein to receive an occlusally-facing
dental prosthesis component and to create a form locking fit with
respect to the occlusally-facing dental prosthesis component when
positioned thereon. According to the exemplary configuration, the
three-dimensional surface shape of the prosthesis interface is
correlated to a three-dimensional surface shape of an
occlusally-facing surface of the occlusally-facing dental
prosthesis component. Additionally, the three-dimensional surface
shape of the prosthesis interface is devoid of concentric
convolutionally shaped segments with respect to a longitudinally
extending axis of the dental implant body, substantially
rotationally symmetrically shaped segments with respect to the
longitudinally extending axis of the dental implant body,
substantially symmetrically shaped segments with respect to the
longitudinally extending axis of the dental implant body,
substantially symmetrically shaped segments with respect to a point
adjacent to the longitudinally extending axis of the dental implant
body, and substantially symmetrically shaped segments with respect
to a plane substantially parallel to the longitudinally extending
axis of the dental implant body. Further, according to the
exemplary configuration, the prosthesis interface can have an
asymmetrically contoured outward facing edge substantially matching
labial, lingual, and first and second proximal portions of a gum
line of the specific pre-identified patient when the dental implant
body is operably positioned within the jaw bone of the
pre-identified patient.
[0042] According to another embodiment of the present invention,
the dental implant body includes a prosthesis interface having a
substantially non-planar surface shape correlated to a surface
shape of an occlusally-facing surface of the occlusally-facing
dental prosthesis component, and having an outward facing
circumferential edge having in its dimensional extension at least
four substantial extrema in a direction of the longitudinally
extending axis of the dental implant body. The dental implant body
also includes a transverse-section that when taken perpendicular to
the longitudinally extending axis and adjacent to the prosthesis
interface has a first dimension in a first direction and a second
dimension in a second direction such that the first dimension is
substantially bigger than the second dimension.
[0043] According to this exemplary configuration, a center portion
of the prosthesis interface is substantially raised in a direction
of the longitudinally extending axis over the outward facing
circumferential edge to create a male portion of a form locking fit
with respect to the occlusally-facing dental prosthesis component
when positioned thereon. Alternatively, a center portion of the
prosthesis interface is substantially indented in a direction of
the longitudinally extending axis over the outward facing
circumferential edge to create a female portion of a form locking
fit with respect to the occlusally-facing dental prosthesis
component when positioned thereon. According to this exemplary
configuration, a shape of the outward facing circumferential edge
can substantially match either a shape of a corresponding outer gum
line surrounding the dental implant body or a shape of a
corresponding bone crest line surrounding the dental implant body
when the dental implant is operably positioned within the jaw bone
of the pre-identified patient.
[0044] Various embodiments to the present invention also include
methods of manufacturing a dental implant to replace a
non-functional natural tooth positioned in a jawbone of a specific
pre-identified patient. An example of such a method can include the
steps of receiving data describing a three-dimensional X-ray image
of at least portions of the patient's dentition defining x-ray
image data, and receiving data describing one of the following: a
physical impression of a dental anatomy and a surface scan of the
dental anatomy, defining impression image data made prior to
removal of the non-functional natural tooth from the jawbone of the
specific patient. The steps can also include forming at least one
three-dimensional virtual model of at least portions of the
non-functional natural tooth to include combining the x-ray image
data and impression image data, and forming the at least one
three-dimensional virtual model of the non-functional natural tooth
including a modeled virtual root portion and a modeled virtual
crown portion responsive to the x-ray image data and the impression
image data.
[0045] The steps can also include designing a dental implant based
upon the at least one virtual model of at least portions of the
non-functional natural tooth. The step of designing the dental
implant includes the steps of forming a virtual dental implant body
modeling a dental implant body having a virtual prosthesis
interface modeling a prosthesis interface of the dental implant
body to receive an occlusally-facing dental prosthesis component.
The step of forming a virtual dental implant body can include
forming the virtual prosthesis interface to have a
three-dimensionally contoured implant body surface shape at least
partially correlated to a surface shape of an occlusally-facing
surface of the modeled virtual crown portion.
[0046] According to a two-piece dental implant body configuration,
the step of forming a virtual dental implant body includes
separating a portion of the at least one three-dimensional virtual
model (including the modeled virtual root portion and modeled
virtual crown portion) along a virtual outer gum line
representation. Beneficially, cutting along the gum line
representation can have the effect of shaping an outward-facing
circumferential edge of a virtual prosthesis interface of the
virtual dental implant body to substantially match a shape of a
corresponding outer gum line surrounding the non-functional natural
tooth prior to removal of the non-functional natural tooth from the
jawbone of the specific pre-identified patient.
[0047] The step of forming the virtual dental implant body can also
include copying at least portions of the modeled virtual crown
portion to form a base shape of the virtual prosthesis interface,
reducing dimensions of the at least portions of the modeled virtual
crown portion to define a virtual prosthesis interface model, and
combining the virtual prosthesis interface model with the virtual
root body portion model to form the virtual dental implant
body.
[0048] According to this configuration, the steps can also include
forming a virtual occlusally-facing dental prosthesis component
modeling an occlusally-facing dental prosthesis component, such as,
for example, a virtual crown component. According to such
configuration, the step of forming the virtual crown component
includes forming a complementing virtual dental implant
body-receiving surface to define a complementing virtual interface
surface modeling a complementing interface surface to receive
occlusally-facing portions of the dental implant body, such that
the prosthesis interface and the complementing interface surface
create a form locking fit therebetween. This can be accomplished by
copying at least portions of the modeled virtual crown portion to
form a base shape of the complementing interface surface of the
virtual crown portion, reducing dimensions of the at least portions
of the modeled virtual crown portion, and combining the virtual
crown portion model with the complementing interface surface model
to form the virtual crown portion.
[0049] According to a three-piece dental implant body
configuration, the step of forming a virtual dental implant body
includes separating a portion of the at least one three-dimensional
virtual model (including the modeled virtual root portion) along a
virtual bone-facing gum line representation (e.g., effectively
shaping the outward-facing circumferential edge of the prosthesis
interface), copying at least portions of the modeled virtual crown
portion to form a base shape of the prosthesis interface, reducing
dimensions of the at least portions of the modeled virtual crown
portion to define a prosthesis interface model, and combining the
virtual prosthesis interface model with the virtual root body
portion model to form the virtual dental implant body.
[0050] According to this configuration, the steps can also include
forming a virtual occlusally-facing dental prosthesis component
modeling an occlusally-facing dental prosthesis component, such as,
for example, a virtual crown component and/or a virtual
transgingival cap component. The virtual crown component can be
formed by employing the procedures described with respect to
forming the virtual crown component in the two-piece configuration,
to include copying at least portions of the modeled virtual crown
portion to form a base shape of a complementing interface surface
of the virtual crown portion, reducing dimensions of the at least
portions of the modeled virtual crown portion, and combining the
virtual crown portion model with the complementing interface
surface model to form the virtual crown portion.
[0051] According to this configuration, the transgingival cap can
be formed using a similar set of procedures. For example, the step
of forming the transgingival cap component can include forming a
complementing virtual dental implant body-receiving surface to
define a complementing virtual interface surface modeling a
complementing interface surface to receive occlusally-facing
portions of the dental implant body. This can be accomplished by
copying at least portions of the modeled virtual crown portion cut
along the bone-facing gum line representation to form a base shape
of the complementing interface surface of the transgingival cap
portion, reducing dimensions of the at least portions of the
modeled transgingival cap portion, and combining the virtual
transgingival cap model with the complementing interface surface
model to form the virtual transgingival cap.
[0052] According to various embodiments of a method of
manufacturing a dental implant, the steps of receiving data,
separating the portion of the at least one three-dimensional
virtual model along the virtual outer/inner gum line
representation, copying at least portions of the modeled virtual
crown portion, reducing dimensions of the at least portions of the
modeled virtual crown portion, and combining the virtual prosthesis
interface model with the virtual root body portion model to form
the virtual dental implant body, and the steps of forming the
virtual occlusally-facing dental prosthesis component(s), in both
the two-piece and three-piece configuration can be performed on a
graphical user interface operably coupled to a computer responsive
to user manipulation of an input device.
[0053] Further, the computer can produce a set of digital data
virtually defining the three-dimensionally contoured implant body
surface shape, which can be utilized by a manufacturing apparatus.
As such, the design and manufacturing/fabricating steps can also
include employing a machine process performed by a computer
numerical control (CNC) based machining apparatus to form
substantial portions of the dental implant body including the
prosthesis interface responsive to the set of digital data, and/or
employing a rapid prototyping process performed by a computer
numerical control (CNC) based rapid prototyping apparatus to form
substantial portions of the dental implant body including the
prosthesis interface responsive to the set of digital data.
[0054] The machine process employed to fabricate the dental implant
can include shaping the outward-facing circumferential edge of the
prosthesis interface of the dental implant to substantially match a
shape of the corresponding outer gum line surrounding the dental
implant described in the received data for the two-piece dental
implant design, and shaping the outward-facing circumferential edge
of the prosthesis interface of the dental implant to substantially
match a shape of the corresponding bone-facing gum line for the
three-piece dental implant design. The shaping process can also
include shaping the prosthesis interface to have the
three-dimensionally contoured surface shape at least partially
correlated to a surface shape of an occlusally-facing surface of
the crown of the nonfunctional tooth to thereby create the form
locking fit with the complementing interface surface of the
occlusally-facing dental prosthesis component when positioned
therein, and shaping the complementing interface surface of the
occlusally-facing dental prosthesis component to have a
three-dimensionally contoured surface shape substantially
dimensionally matching the three-dimensionally contoured surface
shape of the prosthesis interface to thereby create/enhance the
form locking fit therebetween.
[0055] The three-dimensionally contoured implant body surface shape
of the prosthesis interface can be formed to include a substantial
asymmetric positive raising extending from the dental implant body.
Such a shaping process can include shaping the substantial
asymmetric positive raising to have a first rising contour
extending from portions of the occlusally-facing surface of the
root body portion adjacent a center of the lingual-facing side
portion and a second rising contour extending from portions of the
occlusally-facing surface of the root body portion adjacent a
center of the labial-facing side, with the second rising contour
being substantially different than the first raising contour when
viewed along a cross-section of the dental implant extending
between the lingual-facing side portion and labial-facing side
portion and vice versa.
[0056] The shaping process can further include shaping an outer
surface of the root body portion of the dental implant body to have
a custom three-dimensional surface shape approximately
dimensionally matching a three-dimensional inner-surface shape of
corresponding surface portions of one or more intra jawbone
anatomical features associated with the non-functional natural
tooth of the specific pre-identified patient. Also or
alternatively, the outer surface shape of the dental implant body
can be shaped to match a three-dimensional outer surface shape of
the root portion of the non-functional natural tooth of the
specific pre-identified patient, a three-dimensional inner surface
shape of a bone socket for the root portion of the non-functional
natural tooth of the specific pre-identified patient, and/or a
combination of the three-dimensional outer surface shape of the
root portion and three-dimensional inner surface shape of the bone
socket for the root portion of nonfunctional natural tooth of the
jawbone of the specific pre-identified patient.
[0057] According to an embodiment of the process related to the
three-piece design, the root body section of the implant is made of
a titanium or other bone friendly material and the transgingival
cap and crown portion are made of a ceramic material. In such
configuration, implementation of the dental implant is generally
performed by connecting the dental implant body with the
transgingival cap at the prosthesis interface, normally prior to
insertion of the root body section into the jawbone of the specific
pre-identified patient. In such application, the transgingival cap
is generally designed and fabricated so that when connected to the
dental implant body and when the root body section is inserted into
the jawbone of the patient, the outward-facing circumferential edge
of the prosthesis interface is substantially below an outer gum
line of the specific pre-identified patient surrounding
lingual-facing, labial-facing, and proximal-facing surfaces of the
non-functional natural tooth as determined prior to extraction
thereof from the jawbone of the patient. Such configuration
enhances osseointegration between the titanium root portion and the
surrounding jawbone, with the gum being in contact with the ceramic
portions.
[0058] In an embodiment of the present invention, a dental
prosthesis is assembled as a one-part ceramic implant body with a
translucent glass-ceramic cap. To achieve a qualitatively high
one-piece dental implant, the white body of the root portion body
is finished in a hot isostatic pressing process. Hot isostatic
pressing (HIP) describes compression of materials to almost its
theoretical density, by applying high temperatures and high
pressure to the work piece of interest, i.e., the prosthesis or
parts thereof. Therefore, firstly, the ceramic implant is covered
with a customized metallic coating, or sintered to a density that
the gas used for the later process step of hot isostatic pressing
cannot transpire or migrate into the object to be pressed. In a
further step, the coated or tightly sintered implant is placed in
an oven with a temperature closely under the melting point of the
ceramic material of the dental implant. Furthermore, an increased
pressure is applied to the coated implant, thereby eliminating
certain defects and flaws. After this process step (often called
hot isostatic pressing), the coating is removed from the body by
e.g., an etching process. The removal of the coating from the
ceramic body can also be achieved by mechanic means. In an
alternative embodiment, the ceramic implant is sintered in a first
process step form its porous structure to be dense to a degree that
the gas media of the following hot isostatic pressing process
cannot invade into the material itself, so that the compressing,
and therefore the elimination of internal defects, can take
place.
[0059] In a further embodiment, the implant body is made of two or
more different materials being assembled and connected by a
soldering process and/or by diffusion bonding. Diffusion bonding
may include technologies connecting different materials on an
atomic level without a facilitating third material. Diffusion
bonding may be facilitated by hot isostatic pressing to provide the
required connection of the adjacent materials to the degree where
diffusion bonding takes place.
[0060] In another embodiment of the present invention, the dental
prosthesis provides a porous outer surface of the root body
portion. Such a porous surface acts as a biocompatible and cell
pleasing environment. Thereby, the process of osseointegration of
the dental prosthesis into the jaw bone or the process of
integration into the periodontal ligament is promoted. The porous
outer surface can be achieved by, e.g., applying ultra-short laser
pulses onto the surface eroding the material without a remnant of
scoria or thermally altered adjacent surface material. Ultra short
means time pulses having a length in time measured in the range of
1 to 1000 pico-seconds or 1 to 999 femto-seconds. Alternatively,
the porous coating can be achieved by milling the outer surface of
the root body portion. Moreover, the porous outer surface can be
achieved by covering the outer surface of the root body portion
with a ceramic porous coating which is applied or assembled in a
customized and well controllable process.
[0061] In another embodiment of the present invention, the
prosthesis comprises a customized form with an upwardly directed
convex surface in the area between the roots of the prosthesis.
Such a form prevents air inclusions from being enclosed in the area
between the roots of the prosthesis.
[0062] In a further embodiment of the present invention, the
one-part implant and the cap are separated by a customized joint.
This customized joint is embodied as a three-dimensional surface
comprising a form that is individually fitted to the design of the
prosthesis and the course of the patient's gingival.
[0063] In another embodiment of the present invention, the overall
fabrication is simplified. In this method, firstly, an impression
is made of the patient's tooth. Moreover, a scan is obtained from a
computed tomography device. Both types of data are combined and
CNC-instructions (CNC: Computerized Numerical Control) are
generated for the fabrication of the milling of the prosthesis and
the dedicated splint. As another enhancement of the present
invention, the overall fabrication process can partly or totally be
executed at the chair side of the dentist executing the treatment
of the patient.
[0064] In yet another embodiment of the present invention, the
surface data obtained from the impression of the tooth and the
surface data obtained from the computed tomography device are
combined utilizing statistical methods.
[0065] A further embodiment of the present invention relates to the
wet delivery process of the presented dental prosthesis. In the
first step, the prosthesis is placed in an open container which is
filled with an isotonic liquid, thereby coating the whole body of
dental implant. Then ultraviolet electromagnetic radiation is
applied onto the prosthesis to enhance the biocompatibility of the
outer surface. In another step the container is closed, placed in a
high temperature oven and loaded with a high external pressure. The
pressure keeps the container from breaking during the increase of
temperature up to values at which the liquid would start to boil
(under normal pressure circumstances). By this step, a
sterilization process is applied on the prosthesis which leaves the
prosthesis in its moisturized environment and, thereby, keeps the
biocompatibility of the outer surface active.
[0066] Directly after placement, the prosthesis may be tied, glued
or otherwise fixated for several weeks to adjacent original or
artificial teeth or tentative implants like mini-screws likewise
with the custom splint according to the invention. In an embodiment
of the present invention, a splint is provided which comprises
recesses formed as holes. These holes enhance the adhesive in
attaching the splint to the prosthesis and its adjacent teeth. In a
further embodiment of the present invention, the aforementioned
splint which is attached only to one of the adjacent teeth. This
splint can be used in cases where only one of the adjacent teeth is
capable of providing primary stability to the prosthesis via the
splint. If the other adjacent tooth is not qualified for a splint
to be attached, this splint design can be utilized.
[0067] For a situation in which the directly adjacent teeth of the
prosthesis are both not capable for a splint to be attached to, a
splint is proposed which attaches to the teeth next to the adjacent
teeth. This specifies a possibility for providing primary stability
to the prosthesis by utilizing the teeth next to the adjacent
teeth. Such a splint can be on particular importance if the
directly adjacent teeth are not capable of providing sufficient
primary stability.
[0068] As an exemplary embodiment of the present invention, the
crown portion of the aforementioned prosthesis forms one part with
the aforementioned splint. I.e., the crown comprises wings reaching
to the adjacent teeth in a way that the wings can be attached to
the adjacent teeth of the prosthesis. In a further embodiment of
this crown with splint wings, the crown portion is attached to the
one-part implant by utilizing a screw. Thereby, the crown portion
with the splint wings can be removed when the implant is fully
integrated in the alveole. After removing the crown portion with
splint, a final cap can be placed on the one-part implant.
BRIEF DESCRIPTION OF THE DRAWINGS
[0069] So that the manner in which the features and advantages of
the invention, as well as others which will become apparent, may be
understood in more detail, a more particular description of the
invention briefly summarized above may be had by reference to the
embodiments thereof which are illustrated in the appended drawings,
which form a part of this specification. It is to be noted,
however, that the drawings illustrate only various embodiments of
the invention and are therefore not to be considered limiting of
the invention's scope as it may include other effective embodiments
as well.
[0070] FIG. 1 shows a procedure of replacing a human tooth with a
prosthesis in accordance with an aspect of the invention.
[0071] FIG. 2 is a detailed cross-sectional view of a natural
tooth.
[0072] FIG. 3 shows the process steps of intra-orally acquiring
three-dimensional data of a human tooth, fabricating an artificial
copy, extracting the natural tooth and replacing it with the
artificial copy according to an embodiment of the invention.
[0073] FIG. 4 shows the process steps of extracting the natural
tooth, extra-orally acquiring three-dimensional data of that tooth,
fabricating an artificial copy and inserting the copy into the
socket of the natural tooth according to an embodiment of the
invention.
[0074] FIG. 5 shows the process steps of acquiring
three-dimensional data of the root of an extracted human tooth,
processing and completing the resulting 3D data with features for
connecting an off-the-shelf abutment and inserting the prosthesis
into the socket of the natural tooth according to an embodiment of
the invention.
[0075] FIG. 6 shows an artificial tooth having a root portion and a
crown portion, the portions representing the root being coated in
order to promote periodontal integration.
[0076] FIG. 7 is a view of an artificial tooth being made from a
material promoting periodontal integration, the crown being coated
with another material having optimized esthetic and/or mechanical
properties.
[0077] FIG. 8 shows an artificial tooth, the portion representing
the crown being made from a material having optimized esthetic
and/or mechanical properties, while the portion representing the
root is made from a material promoting periodontal integration.
[0078] FIG. 9 is a view of an artificial tooth being made from a
material having optimized esthetic and/or mechanical properties,
the portions representing the root being coated in order to promote
periodontal integration.
[0079] FIG. 10 shows an artificial tooth being embedded in the
socket of the natural tooth.
[0080] FIG. 11 shows a view of a segmented artificial tooth, the
segment representing the root being connected to the segment
representing the crown by a connecting element.
[0081] FIG. 12 is a view of a segmented artificial tooth, the
segment representing the root and the segment representing the
crown having an interlocking connection.
[0082] FIG. 13 is a cross-sectional view of a segmented artificial
tooth, the segment representing the root being expanded using a
screw and a dowel in order to support osseointegration and improve
physical stability after implantation.
[0083] FIG. 14 shows an extraction socket.
[0084] FIG. 15 is the artificial tooth of FIG. 13 inserted into the
extraction socket and expanded.
[0085] FIG. 16 is a view of an artificial tooth according to FIG.
15, wherein voids between the socket and the tooth are filled with
a bone promoting substance.
[0086] FIG. 17 shows an artificial tooth inserted into the
extraction socket and firmly pressed against the walls of the
socket in order to promote osseointegration into the bone.
[0087] FIG. 18 shows an extraction socket of a patient, the socket
filled with a bone promoting substance, and a connection element
for the root being embedded into the bone promoting substance.
[0088] FIG. 19 shows an artificial crown attached to the connection
element of FIG. 18 after the bone promoting substance has been
replaced by newly grown bone.
[0089] FIG. 20 is a view of a bridge according to prior art.
[0090] FIG. 21 is a view of a bridge according to an embodiment of
the present invention.
[0091] FIG. 22 shows an artificial tooth, the portion representing
the root being slightly reduced in size compared to the natural
tooth.
[0092] FIG. 23 shows a natural tooth having strongly crooked roots
and the artificial substitute, wherein the shape of the substitute
has been altered in order to allow for simplified insertion into
the natural socket.
[0093] FIG. 24 shows a natural tooth suffering from partial root
loss due to root resorption or a surgical procedure and an
artificial substitute, the shape of the artificial tooth being
optimized for better adaption to the natural socket.
[0094] FIG. 25 shows a tooth socket after extraction. Due to root
resorption, the size of the socket has been reduced over time. In
order to enhance anchoring, the artificial replacement will have a
root portion of greater size. Therefore, the socket is surgically
enlarged.
[0095] FIG. 26 shows a dental implant according to prior art.
[0096] FIG. 27 shows another implant according to prior art.
[0097] FIG. 28 shows a removable denture according to prior
art.
[0098] FIG. 29 shows 3D data resulting from the imaging of the root
of a natural tooth.
[0099] FIG. 30 shows the 3D data of FIG. 29, but cleanly cut at the
top, and a virtual hexagon socket from an electronic library.
[0100] FIG. 31 shows a partial cross-section of an implant having a
hexagon socket and a thread for attaching the abutment.
[0101] FIG. 32 shows an arbitrary portion of an STL file in ACSII
format.
[0102] FIG. 33 shows an arbitrary portion of an IGES file in ACSII
format.
[0103] FIG. 34 shows an implanted artificial tooth, the voids
between the root portion and the extraction socket filled with a
bone promoting substance.
[0104] FIG. 35 is a cross-sectional view of the components of a
segmented artificial tooth, the segment representing the root being
expandable by being slotted and having a conical thread.
[0105] FIG. 36 is the artificial tooth of FIG. 35 inserted into the
extraction socket and being expanded by inserting screw into the
conical thread.
[0106] FIG. 37 is a known two-part implant for
osseointegration.
[0107] FIG. 38 is a known three-part implant for
osseointegration.
[0108] FIG. 39 is a single-tooth prosthesis for osseointegration
showing a custom shaped torus as a barrier against tissue
growth.
[0109] FIG. 40 is a single-tooth prosthesis showing a
labyrinth-sealing feature as a barrier against bacteria
infiltration.
[0110] FIG. 41 is a single-tooth prosthesis showing a build-up of a
crown portion of translucent ceramic layers.
[0111] FIG. 42 is a single-tooth prosthesis showing a root portion
having drug releasing surface.
[0112] FIG. 43 is a single-tooth prosthesis and a custom-made
splint for positioning and fixation of such to the adjacent dental
structure.
[0113] FIG. 44 shows the process steps of fabricating a one-piece
prosthesis partially from in-vivo imaging data and partially from
imaging data of impressions, merging those imaging data, design a
prosthesis and a custom splint, and fabricating the prosthesis and
the splint by computer numerical control (CNC) machining.
[0114] FIG. 45 shows the process steps of fabricating a one-piece
prosthesis from design data, completing the design by segmenting
the prosthesis in a root portion that includes an abutment and a
crown portion, fabricating the root portion by computer numerical
control (CNC) machining, fabricating a negative shape of the crown
portion as a mould by computer numerical control (CNC) machining,
and using the root portion and the mould to complete the one-piece
prosthesis shaping the crown potion.
[0115] FIG. 46 shows the process steps of fabricating the custom
splint from design data, and fabricating a model of the splint by
rapid prototyping, building a mould around the splint, burning out
the model and casting the splint by investment casting.
[0116] FIG. 47 shows the process steps of clinically inserting a
one-piece prosthesis into an extraction socket, positioning the
prosthesis in relation to the adjacent teeth with the custom splint
and fixating the prosthesis in relation to the adjacent dental
structure with adhesive means.
[0117] FIG. 48 shows the process steps of clinically preparing an
extraction socket with a laser technology based device.
[0118] FIG. 49 shows the process steps of manufacturing a
prosthesis where autologous biological tooth or tissue material is
taken from a patient to be used in an tissue engineering process to
configure the root portion of the prosthesis for periodontal
integration.
[0119] FIG. 50 shows the process steps of manufacturing a
prosthesis where autologous biological bone material is taken from
a patient to be used in an tissue engineering process to configure
the root portion of the prosthesis for osseointegration.
[0120] FIG. 51 shows the process steps of fabricating a one-piece
prosthesis.
[0121] FIG. 52 shows the customized hot isostatic pressing
method.
[0122] FIG. 53 shows the process of coating the one-piece
prosthesis with a porous ceramic.
[0123] FIG. 54 shows the process of coating the one-piece
prosthesis with a hydroxyapatite-layer.
[0124] FIG. 55 shows a method for creating a porous outer surface
on the root body portion of the one-piece dental prosthesis by
utilizing pico/femto-laser pulses.
[0125] FIG. 56 shows a method for creating rounded edges in the
porous outer surface on the root body portion of the one-piece
dental prosthesis.
[0126] FIG. 57 shows a method for creating a porous outer surface
on the root body portion of the one-piece dental prosthesis by
milling.
[0127] FIG. 58 shows an overall fabrication method of the
prosthesis and its dedicated parts, including a splint.
[0128] FIG. 59 shows a perforated splint comprising holes.
[0129] FIG. 60 shows a splint which is attached only to one of the
adjacent teeth.
[0130] FIG. 61 shows a splint being attached to the adjacent teeth
and teeth next to the adjacent teeth.
[0131] FIG. 62 shows a prosthesis with a crown portion body forming
one part with a splint.
[0132] FIG. 63 shows a cut view of the aforementioned prosthesis
with a crown portion body forming one part with a splint of FIG.
62.
[0133] FIG. 64 shows an iterative method for processing previously
acquired data for the fabrication of the mentioned prosthesis.
[0134] FIG. 65 shows a modification of prosthesis comprising a
special shape in the area between the roots of the prosthesis.
[0135] FIG. 66 shows a method for the wet delivery of the dental
prosthesis.
[0136] FIG. 67 shows a color pad assembly for esthetically
optimizing the dental prosthesis.
[0137] FIG. 68 shows a natural tooth and a prior-art dental
implant.
[0138] FIG. 69 shows a dental implant prosthesis with a
custom-shaped joint between an implant body and a crown.
[0139] FIG. 70 shows a dental implant prosthesis with a
custom-shaped joint between an implant body and a crown.
[0140] FIG. 71 shows a compound one-piece prosthesis with a first
joint between an implant body and a transgingival cap and a second
joint between the transgingival cap and a crown.
[0141] FIG. 72 shows an exploded view of a dental prosthesis
consisting of a crown, a trans-gingival portion, an implant body,
and a splint.
[0142] FIG. 73 shows labial view of a dental implant
prosthesis.
[0143] FIG. 74 shows cross-sectional labial view of a dental
implant prosthesis.
[0144] FIG. 75 shows a top view and a cross-sectional transversal
view of a dental implant body.
[0145] FIG. 76 shows a proximal lateral view of a dental prosthesis
and a cross-sectional lateral view of the dental implant body.
[0146] FIG. 77 illustrates combining a surface image with an x-ray
image to form a three-dimensional virtual model
[0147] FIG. 78 illustrates the division or separation of parts of a
virtual model.
[0148] FIG. 79 illustrates copying of portions of the divided
virtual model.
[0149] FIG. 80 illustrates the combining of virtual models to form
a virtual crown portion.
[0150] FIG. 81 illustrates the combining of virtual models to form
a virtual dental implant body.
[0151] FIG. 82 illustrates the attachment of a crown portion of a
dental implant to a dental implant body to form the dental
implant.
[0152] FIG. 83 illustrates the division or separation of parts of a
virtual model.
[0153] FIG. 84 illustrates copying of portions of the divided
virtual model.
[0154] FIG. 85 illustrates the combining of virtual models to form
a virtual dental implant body portion.
[0155] FIG. 86 illustrates the combining of virtual models to form
a virtual transgingival cap portion.
[0156] FIG. 87 illustrates the combining of virtual models to form
a virtual crown portion.
[0157] FIG. 88 illustrates the attachment of a transgingival cap
portion of a dental implant to a dental implant body and attachment
of a crown portion to the transgingival cap portion to form the
dental implant.
[0158] FIG. 89 illustrates a completed three-piece dental
implant.
DETAILED DESCRIPTION
[0159] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings, which
illustrate embodiments of the invention. The invention may,
however, be embodied in many different forms and should not be
construed as limited to the illustrated embodiments set forth
herein. Rather, these embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey the
scope of the invention to those skilled in the art. Like numbers
refer to like elements throughout. Prime notation, if used,
indicates similar elements in alternative embodiments.
[0160] Current methods for replacing damaged teeth have several
disadvantages. For example, conventional bridge implants require
healthy teeth to be ground, and osseointegrated implants are
drastically invasive. Additionally, these prostheses have a limited
average lifetime. Removable dentures (800) as shown in FIG. 28 are
certainly the final prosthetic option. An object of the invention
is to design and manufacture customized dental prosthesis for
replacing human teeth. FIG. 1 illustrates a method of replacing a
human tooth with a customized dental prosthesis according to an
embodiment of the invention. First, in step (A) a copy (200) of the
natural tooth (100) to be replaced is fabricated. Then, in step (B)
the natural tooth (100) is replaced with the prosthesis (200).
[0161] FIG. 2 shows a natural tooth embedded in its socket. The
pulp (1020) holds nerves and blood vessels (1070). It is surrounded
by dentine (1010), which is covered with enamel (1000). The root
portions have a thin layer of cement (1050) providing connection to
the ligament (1040), which serves to anchor the tooth to the bone
(1060). The outside of the bone is covered with gum (1030).
[0162] FIGS. 26 and 27 show conventional implants. The implanted
portion (610 and 710) is an off-the-shelf part to be inserted into
a hole drilled into the jaw bone. The crown (600 and 700) is
generally customized to the individual tooth it is replacing.
[0163] According to an embodiment of invention, a dental prosthesis
is individually shaped and integrated into the natural extraction
socket of an individual specifically identified patient. The shape
of the portions of the prosthesis representing the root
substantially copies the natural root of the tooth that was located
in the socket. However, the shape may be modified in order better
adapt to the natural socket or to ease insertion of the prosthesis.
Also, the socket may be surgically adapted for the same reasons.
For example, damaged and infected soft tissue, tooth or bone
substances would not allow for immediate implantation. Then, a
dental laser may be used to remove the damaged structures. The most
commonly used dental lasers are diode, carbon dioxide, erbium YAG,
erbium YSGG, Nd:YAG, and argon lasers. The applications for each
wavelength depend on the absorptions of laser energy by different
tissue types. The Erbium family can be used for caries removal,
bone surgery, mucosal surgery and gum surgery. While other laser
families are mainly used in soft tissues surgeries. Benefits in
laser assisted dental treatment include decreased morbidity after
surgery, hemostasis, and a reduction in the need for anesthetics in
selected cases.
[0164] A Erbium laser, for example, emits light with a wavelength
of 2940 nanometers, which is primarily absorbed by water. Decayed
material has an extremely high water content so that the laser
light energy evaporates the damage and is able to cut very
precisely with little or no collateral damage depending on the
settings used during the surgery. When used on hard tissues the
Erbium laser energy that touches the hard tissue heats up the water
within the hard tissue and causes that water to be turned into
steam. That causes a mini-explosion to occur and the hard tissue is
"ablated" (removed). Diode lasers in general use as an active
medium, a semi-conductor P-N junction made in a GaAlAs crystal. A
flexible fiber is used to transmit the laser energy to the surgical
site.
[0165] According to an embodiment of the present invention, a
segmented prosthesis can be used. A segmented, also referred to a
segment, prosthesis is one in which a first segment is implanted
into the extraction socket and second segment, for example, a
portion representing the crown of a tooth, is attached to the
segmented portion. Accordingly, segmented prosthesis include at
least two separate portions which may be manufactured and implanted
at separate times. The segment which is implanted into the
extraction socket is a representation of the root of the natural
tooth and can be manufactured based on 3D imaging data. The segment
representing the crown can be manufactured according to standard
procedures known in the art.
[0166] An embodiment of the present invention comprises the
following steps: (i) Recording and digitizing (scanning) the
three-dimensional anatomical shape of a human tooth or dentition;
(ii) Obtaining a virtual model of the tooth as data record; and
(iii) Manufacturing of the prosthesis, based on the
three-dimensional data that have been obtained by the scan and if
applicable, optimized.
[0167] The data may either be recorded intra-orally from the
patient, such as with a 3D camera, a micro laser optical device, a
computerized tomography apparatus, or an ultrasound apparatus, or
be recorded extra-orally by scanning an extracted tooth. If
required, the model can be modified in order to ease insertion or
to receive aids for the final correct positioning of the fabricated
prosthesis. The prosthesis can be directly produced by milling,
grinding or rapid prototyping, for example, at a dentist's office
or in a laboratory. It can also be produced using conventional
laboratory procedures like casting. Preferably, the implant portion
representing the root is manufactured using CAM methods, e.g.,
based on an acquired virtual model, while other portions of the
prosthesis, for example, representing the crown or bridge, can be
manufactured using standard procedures known in the art.
[0168] The process of milling or grinding dental crowns and inlays
from ceramic material based on digital data was successfully
introduced to dentistry approximately twenty years ago by SIEMENS
(now Sirona, Bensheim, Germany) under the brand name CEREC. A
modification of the SEREC system as would occur to one of ordinary
skill of the use of suitable similar CAD/CAM and CNC design and
manufacture as would occur to one of ordinary skill in the art, can
be utilized. Although conventional prosthesis manufacturing
systems, such as the CEREC system, are generally closed systems,
one skilled in the art would readily appreciate these closed
systems can be modified such that they may be readily integrated
into the methods of the invention. Furthermore, certain embodiments
of the invention disclosed herein relate to standard off-the-shelf
CAD/CAM and CNC components that can be readily integrated into the
disclosed methods
[0169] Preferably, at least the customized implant portion of the
dental prosthesis is fabricated using a CAD/CAM based method and
system, wherein the three-dimensional shape of an extracted tooth
is scanned and substantially copied, using a 3D scanner, multi-axes
CNC machinery and biocompatible material or material later to be
covered with a thin layer of biocompatible material that is
suitable to be integrated into and adopted by the existing
periodontal ligament cell structure of an individual patient.
[0170] An overview of a method for replacing a tooth according to
the invention is shown in FIG. 5. First, the tooth to be replaced
is extracted (step G) and properly cleaned (step M). Then 3D
imaging (step N) is performed in order to obtain 3D data (D)
representing the three-dimensional shape of the root of the tooth.
The resulting 3D data is imported into CAD software and displayed
to an operator (step E). At this point, the 3D data may be
modified, for example, to alter the shape of the root of the
virtual model. It should be noted that although FIG. 5 contemplates
possible interaction with an operator, one skilled in the art would
readily appreciate that this functionality may be fully automated.
Additional features may be added from a digital library and merged
into the 3D root data (step S). The resulting 3D data is converted
into IGES format and exported (step H) to a CAM system for
fabricating (step I) the prosthesis (J). The fabricated prosthesis
is then coated with a substance promoting bone ingrowth (step K).
It should be noted that coating the prosthesis is an optional step.
The prosthesis is then implanted into the extraction socket (step
L).
[0171] The tooth to be replaced, for instance, a lower left incisor
(having an envelope volume of approximately 7 mm.times.8
mm..times.23 mm) is extracted in a surgical environment, then
disinfected and cleaned in a solution of hydrogen peroxide. The
three-dimensional shape (scanning) of the extracted tooth may be
obtained using, for example, a light-based scanner like ATOS II SO
(gom GmbH, Braunschweig, Germany). In a first step, the root of the
tooth is scanned. To achieve an optimal surface for optical
scanning, the root is covered with a thin layer of TiO.sub.2 powder
(like CEREC powder from Sirona, Bensheim, Germany) that is applied
with an atomizer using compressed air. Other coatings are also
applicable that can for instance be applied by air-brush painting
or a regular brush. For example, it is possible to "shake-up"
TiO.sub.2 powder in alcohol applying a uniform thin layer of
TiO.sub.2 by airbrushing generating this way high-precision data
during scanning. A portion of the crown of the tooth is attached to
the turntable of the scanner using a removable adhesive material
(like for instance wax used in dental laboratories).
[0172] The turntable is then rotated in 15 degree increments
step-by-step for a 360 degree view. The scanner scans at each of
the 15 degree increments the optically accessible root surface of
the tooth and is thus generating and exporting digital surface data
representing the scanned portions of the three-dimensional shape of
the surface of the root. The turntable is controlled by the
software delivered with the scanner.
[0173] The digital surface data consists of multiple measurement
data points each having an x, y, and z coordinate and together
having a density better than 0.1 mm and an accuracy noise of less
than 0.05 mm. Alternatively, other resolutions, accuracies, and
coordinate systems including but not limited to cylindrical or
spherical coordinate systems can be employed by those skilled in
the art. The data points are exported in STL format. This widely
used file format describes a surface or portions of a surface by
interconnected triangles. STL files can be encoded either binary or
in ASCII format. FIG. 32 shows an arbitrary example of a portion of
such a file in the easily readable ASCII format.
[0174] Reference elements that are fixed to the turntable are
additionally scanned at each increment. The ATOS II scanner
software is able to detect such reference elements in the STL data
of each incremental scan. Based on the reference elements it
automatically transforms, superimposes and combines the incremental
scans. The result is a comprehensive STL file describing the
surface of the root of the tooth.
[0175] Other suitable imaging methods include but are not limited
to CT, CBCT, MRT, ultra sound, destructive scanning, active
triangulation, passive triangulation, confocal scanning, and TOF
(Time-of-Flight). Such methods are generating either surface
descriptions, for example, in STL-format or volumetric data for
example, in a so called "voxel"-format that can be transformed into
surface data by generally available software applications known to
those skilled in the art, and vice versa.
[0176] The scan of the root is then loaded into a CAD software
application called MAGICS (Materialise, Leuven, Belgium). Using the
cutting features of MAGICS, the occlusal facing edge of the virtual
root model (FIG. 29, 20000), which will be uneven and "frayed" in
the original scan data, will be straightened in order to receive a
clean contour. A straight cut will be performed at a location
(19030) where scan data is substantially complete. This is
demonstrated in FIGS. 29 and 30. Then, from an electronic library,
a virtual hexagon socket is selected and additionally loaded into
MAGICS and placed on top of the virtual root, as shown in FIG. 30.
Note, when terms like "top" and "bottom" are used in this context,
it is always assumed the root tip points downwards. The hexagon
socket consists of the hexagon shape (19000) fitting to the
off-the-shelf abutment that will later be mounted to the artificial
root, and a junction portion (19020) providing the transition to
the virtual root. Since there is a significant variation in root
thicknesses and shapes, a selection of hexagon sockets is available
in the electronic library, each having a different junction portion
in order to receive a minimal gap between the virtual root and the
virtual socket.
[0177] In a next step, the so-called "stitching" functionality of
MAGICS is used to close the gap (19010) between the virtual root
and the virtual socket and, if applicable, also other gaps that may
be a result of incomplete scanning. The outcome of this step is a
virtual representation of a solid. In this context, a
three-dimensional solid is an unambiguous numerical description of
the surface of the geometrical shape of a three-dimensional object,
the numerical description showing no holes and clearly identifying
the inside and the outside of the surface.
[0178] The hexagon socket of the actual prosthesis also needs to
have an inside thread (FIG. 31, 21000) to receive the screw used
for mounting the crown. In the illustrated embodiment, this thread
is not part of the virtual model. Rather, the first step of
manufacturing is to cut this thread into the workpiece used for
fabricating the prosthesis, and then to use it to mount the
workpiece to the machine table of the milling machine. To ensure
spatial integrity, the coordinate system of the virtual solid must
be placed properly. Preferably, the origin of the coordinate system
will be placed in the center of the hexagon, one of the main axes
running parallel to the midline of the thread as shown in FIG.
31.
[0179] The STL data describing the solid representing the tooth are
then converted to an IGES data format. This is performed using, for
example, a software named SolidWorks (SolidWorks Corp., Concord,
Mass. USA). The IGES file allows generating a CNC sequence to
machine an artificial tooth from a piece of biocompatible material
like titanium or a titanium alloy (like Ti.sub.6Al.sub.4V), that
consists, for example, of more than 60% of titanium. FIG. 33 shows
an arbitrary example of a portion of such a file. Ceramic material
and other biocompatible materials (including but not limited to
stainless steel (like 1.4435, 1.4542 or 1.4548), synthetics,
elastics, plastics, resin-modified glass-ionomer cement,
hybrid-ionomer cement, resin-enforced cement, and other synthetic
and plastic materials) are also applicable. For manufacturing the
prosthesis for the above mentioned lower left incisor a workpiece
having a size of 20 mm..times.10 mm..times.10 mm is adequate. For
machining, a traditional 5-axis CNC milling device with a
high-speed spindle is used. Other workpiece sizes and multi-axes
CNC machining devices can be employed in this context by those
skilled in the art.
[0180] After cutting the thread that will be located in the center
of the hexagon of the finished prosthesis, the workpiece is screwed
to an adapter on the machine table of the milling machine by using
said thread. The adapter is either shaped so that it leaves
sufficient clearance for the milling spindle and the cutter, or a
disposable adapter is used so that portions of the adapter itself
may be milled off. After teaching the machine the position and
inclination of the workpiece, entering the machine and process
parameters and overlapping the physical workpiece with the virtual
shape, the root shape of the left lower incisor is machined by
grinding the workpiece down layer-by-layer to the desired
shape.
[0181] After manually cleaning, removing the excess, if applicable,
polishing, degreasing, etching rinsing, disinfecting and drying the
workpiece, it is ready for insertion. In order to improve the
integration of the implant into the bone, further treatments
according to the prior art, are possible. Sand-blasting with
ceramic particles for instance creates a rough, and thus,
significantly enlarged surface. Other porous-surfacing technologies
can be used in this context too. Coating the surface with
hydroxylapatite stimulates bone formation promoting a
physico-chemical bond. Other coatings suitable to facilitate
include but are not limited to pharmaceuticals, ancestral cells
(e.g., multi-potent cells, fat-derived stem cells and other stem
cells), and proteins. Instead of coating, the aforementioned
substances can be applied by others means including but not limited
to adjunction and injection.
[0182] Before inserting the prosthesis, the extraction socket will
be properly scraped out or curetted and cleaned. In another
embodiment, the socket will then be filled with Bioplant (Kerr
Corporation, Orange, Calif.). Bioplant is a bone promoting
substance. It is hydrated with marrow blood from the extraction
socket and then injected into the socket using a special syringe
delivered with Bioplant. Bioplant fills any voids present between
the socket and the implant. After insertion of the implant,
additional Bioplant may be applied in order to fully embed the
implant below the hexagon socket. FIG. 34 shows the prosthesis
embedded in the extraction socket, the voids being filled with
Bioplant (13000). Alternatively, or in addition, bone demineralized
matrix proteins, bone growth stimulating proteins, or other growth
stimulating substances may be applied or otherwise used to
facilitate the osseointegration and the building of the secondary
stability of the prosthesis. The application of growth stimulating
substances can be combined with antibiotic substances to avoid or
suppress infection or inflammation. Drug releasing surfaces can be
loaded with the aforementioned medical substances or any
combination thereof releasing such substance(s) over a period of
time. Growth stimulating substances can include or be derived from
autologous, allogenic, or animal-derived cells or tissue. In order
to avoid the growth of the gum into the void between the implant
and the extraction socket, membrane techniques known to those
skilled in the art can be employed. Also, the top of the implant
excluding the hexagon has been covered with Bioplant. A healing cap
is placed on top of the implant. The implant is then secured to the
adjacent teeth for about six weeks by means of a light-curing resin
strip known to those skilled in the art.
[0183] After the implant is healed in, standard procedures of prior
art can be performed. After an alginate impression has been taken,
a customized tray is fabricated, reinforced and perforated where
the implant is located. An impression post is screwed onto the
implant, and the customized tray is placed onto the dentition. The
void between the perforation in the tray and the impression post is
filled with impression putty. After the putty has set, the screw
attaching the impression pin to the implant is unscrewed, and the
impression is removed from the patient's dentition and sent to a
specialized laboratory. Based on the impression and an impression
of the opposing jaw, the technician will fabricate a crown. When
the crown is delivered, the abutment is screwed to the implant, and
the crown is cemented onto the abutment.
[0184] Another substance suitable to promote bone regeneration is
CERASORB DENTAL (curasan AG, Kleinostheim, Germany). It consists
mainly of pure phase beta-tricalcium phosphate (beta-TCP). CERASORB
is completely resorbed and replaced by natural bone structure.
Collagen fibers and blood vessels invade the interconnecting
micro-pores of the CERASORB granules (micro-pores) and the
inter-granular cavities (macro-pores). The primary-grain size of
10-63 .mu.m does not provoke phagocytosis by macrophages.
[0185] Patent Application publication number 2005/0084513, which is
hereby incorporated by reference in its entirety, discloses a
coating for an implant surface. The coating promotes
characteristics on the implant surface such as reducing protein
unfolding, preventing inflammatory and fibrotic cell accumulation,
reducing the number of such cell attachment sites and preventing
other adverse biological reactions. The coating may be applied on
any material via physical and/or chemical binding. It may also be
used for in vitro purposes.
[0186] Another option is to apply nano-crystalline diamond coating.
A coating named r-BeSt (Hartstoffbeschichtungs GmbH, Innsbruck,
Austria) shows 100% biocompatibility due to the pureness of the
diamond coating, an optimal interconnection between substrate and
diamond coatings, good tribological properties due to the
smoothness of the layer and an active surface for bio-chemical
reactions. Another option is to apply inert coating with
pyrolyt-carbon, which includes isotropic and non-isotropic
structures.
[0187] In yet another embodiment sputter technologies are used to
apply, for example, zircon-oxide surface on a custom-made titanium
body to prepare adventurous surface features. For example, it is
known that zirconium-oxide is tissue friendly. Sputter technologies
include but not limited to ion sputtering, plasma sputtering and
other sputtering technologies used under vacuum.
[0188] In another embodiment of the invention, an unsegmented
prosthesis will be fabricated as shown in FIG. 9. The steps of the
process are outlined in FIG. 4. The tooth to be replaced is
extracted (step G) and properly cleaned (step M). Then 3D imaging
(step N) is performed in order to obtain 3D data representing the
three-dimensional shape of the complete tooth. The resulting 3D
data (D) is imported into CAD software and displayed to the
operator (step E). The shape is modified and optimized as needed
(step F, see also FIGS. 23 and 24). The resulting 3D data is
converted into IGES format and exported (step H) to a CAM system
for fabrication of the prosthesis (step I). The finished prosthesis
(J) may be coated with a substance promoting bone ingrowth (step K)
and is then implanted into the extraction socket (step L). It
should be noted that although FIG. 4 contemplates possibly
interaction with an operator, one skilled in the art would readily
appreciate that this functionality may be fully automated.
[0189] The prosthesis is preferably made from a material supporting
osseointegration, such as, for example, porous calcium phosphate
ceramic. This material provides a scaffold for bony ingrowth. In
order to fabricate a complete prosthesis, the shape of the crown
must also be available. Therefore, after the imaging of the root
portion has been completed as described above with respect to FIG.
5, the crown is scanned. It will also be covered with TiO.sub.2
powder. A portion of the root of the tooth is attached to the
turntable of the scanner while the crown is optically exposed in
order to be scanned in the same incremental manner. A second
comprehensive STL file is accordingly generated describing the
surface of the crown of the tooth. The scan of the root as well as
the scan of the crown is performed in a way that a significant
overlapping area of the surface of the counterpart is included in
each scan.
[0190] The scan of the root and of the crown are then loaded into
MAGICS and manually maneuvered to a best fit using the overlapping
areas of both scans, and merged into one STL data file. In order to
increase accuracy, software detecting best fit for two independent
surfaces can also be used. After manually removing outliers of the
scanned measurement data and identifying and correcting deficient
triangles and adding missing parts (if required), the resulting STL
surface data forms a three-dimensional solid representing the
overall shape of the extracted tooth.
[0191] The STL data is then converted to an IGES data format. For
fabricating the above mentioned lower left incisor, a piece of
calcium phosphate ceramic having a size of approximately 25
mm.times.10 mm.times.10 mm can be worked using a traditional 5-axis
CNC milling device with a high-speed spindle (about 60.000 rpm), a
spherical diamond cutter having a diameter of the tip of the cutter
of 1 mm, and water cooling. The ceramic workpiece is clamped to the
machine table of the milling machine. After teaching the machine
the position and inclination of the workpiece, dialing in the
machine and process parameters, and overlapping the physical
workpiece with the virtual shape, a first portion representing the
root shape of the lower left incisor is machined by grinding down
layer-by-layer the workpiece to the shape of interest. Then, a
fixture is made for that specific workpiece to clamp the workpiece
at the already machined first portion, for instance by grinding a
portion of the geometrical negative shape of the fist portion into
the receiving part of the fixture.
[0192] After teaching the machine position and inclination of the
reoriented workpiece clamped into that customized fixture, entering
machine and process parameters, and overlapping the physical second
part of the workpiece with the virtual shape of the second portion
to be machined, the crown shape of the left lower incisor is
machined by grinding the workpiece down layer-by-layer to the
desired shape. After properly cleaning, removing the excess, and
degreasing, the prosthesis is ready for insertion into the
extraction socket. After the implantation, the artificial tooth is
fixed substantially to the same position and inclination of the
extracted tooth by being bonded with light curing resin strip to
the adjacent teeth.
[0193] An advantage of this embodiment of the invention is that the
complete replacement of the natural tooth is performed in one
appointment. After the prosthesis has healed in, only the resin
strip initially securing the prosthesis to the adjacent teeth must
be removed. A significant amount of laborious steps can thus be
avoided. FIG. 17 shows an osseointegrated unsegmented tooth (900).
Osseointegration is achieved in marked areas (14000).
[0194] Using computer networks, all process steps may be carried
out by different and independent parties. The imaging part can for
instance be performed at the dentist's office, at a hospital or at
a location specialized in imaging. The imaging data can then be
transferred to a location where the imaging data are further
processed in order to ready them for manufacturing. After the
design is finished, the data can again be transferred to the
dentist for further optimization and/or approval. Consulting a
remote specialist in difficult cases using data transfer may also
be applicable. Such a remote specialist may be a clinician or an
expert in manufacturing or laboratory procedures. Then, the data
can be transferred to a remote manufacturing location. All these
data transfers can for instance be performed via the Internet,
using preferably Virtual Private Network channels to secure
privacy, or through a local area network.
[0195] In yet another embodiment shown in FIG. 7, the implant will
be made by one type of biocompatible material (9020), for instance,
titanium or a titanium alloy, and the portion representing the
crown will be coated with another biocompatible material (9010),
for instance, ceramic to support both optimal physical strength and
esthetics. Alternatively, the crown portion is not coated, but is
made from a material different from the material used for the root
portion. FIG. 8 shows an artificial tooth, with the portion
representing the crown being made from a material having optimized
esthetic and/or mechanical properties, while the portion
representing the root is made from a material promoting periodontal
integration. Both portions can be attached to each other by a
variety of connection methods: They can be bonded, cemented, fixed
mechanically (either by a screw or an interlocking surface), or
they can be fabricated from a workpiece that is already comprising
different materials. Sintering would be one of the suitable
processes. Therefore, the prosthesis can be fabricated either
segmented, with the parts being connected to each other either
before or after implantation or the complete prosthesis is made in
a single process. In another embodiment, a material promoting cell
growth and providing good adhesion for cells is used for the root
portions. FullCure 720 may serve as an example of such a material.
This is an acrylic based photopolymer and distributed by Object
Geometries Ltd., Hebron, Israel. This material can be processed by
a rapid prototyping process named "Object Print". Devices for this
process are also distributed by Object Geometries Ltd.
[0196] In another embodiment, the prosthesis is made from
stabilized tetragonal zirconium oxide polycrystalline or another
aluminum oxide or zirconium oxide material known to those skilled
in the art (inCoris ZI, inCoris AL, VITABLOCS, and CEREC Blocs
distributed by and Ivoclar Vivadent and SIRONA). Alternatively, the
prosthesis can be made of titanium or a titanium alloy and surface
coated with zirconium oxide for example, in sputtering technologies
(as offered by Clinical House Europe GmbH).
[0197] In case of the osseointegration of a prosthesis according to
an embodiment of the invention disclosed herein, INFUSE.RTM. can be
used. Bone Graft (Medtronic Sofamor Danek) can be applied to
stimulate bone formation. INFUSE.RTM. Bone Grafts consists of two
parts--a solution containing rhBMP-2 (recombinant human bone
morphogenetic protein 2) and the ACS (absorbable collagen sponge).
The protein is a genetically engineered version of a natural
protein normally found in small quantities in the body. The
stimulation of bone formation is key to develop osseointegration,
and to fill voids in between the extraction socket and the actual
prosthesis in an accelerated manner. Other growth aiding proteins
like bone morphogenetic protein (BMP), dentin matrix protein (DMP),
platelet-derived growth factor (PDGF) and/or other bone growth
stimulating proteins may be applied or otherwise used additionally
or instead in order to facilitate integration, healing, and rebuild
of the bone structure of the patient.
[0198] In another embodiment of the invention, cell attracting
cytokines are attached or applied to the implant surface to be
integrated. For example, that cytokine material InductOss (Wyeth)
attracts bone building cells (i.e., osteoblasts) to enhance
osseointegration. In contrast specific cytokine material can be
applied to attract cementoblasts and/or fibroblasts to regenerate
the perio-type membrane and avoid osseointegration.
[0199] In a further embodiment of the invention, cells (including
but not limited to autologous and/or allogeneic cells) are attached
or applied adjacent to or contained in a gel-type scaffold. Agarose
gel scaffolds, platelet gel and/or fibrin (Baxter) based scaffolds
are used. In order to create a geld type fibrin scaffold, the two
components of fibrin sealant are mixed in a ratio 80:20 instead of
50:50.
[0200] In yet another embodiment, the prosthesis will not be
osseointegrated, but adopted by the ligament of the extraction
socket. In this case the prosthesis is coated with a material
promoting periodontal adoption. A thin layer of about 0.05 mm to
0.2 mm of resin-modified glass-ionomer cement (FIG. 9, 9000) is
applied to the surface of the part of the workpiece being inserted
into the extraction socket. FIG. 6 shows a segmented artificial
tooth, the crown (10000) being made from a material having
optimized esthetic and/or mechanical properties, and the root
portion (10010) being coated with a substance (9000) promoting
periodontal integration, for instance, glass ionomer cement. FIG. 9
shows an artificial tooth (9030) made from a material suitable for
crowns like ceramics, the root portion being coated with a
substance promoting periodontal integration. Substances promoting
periodontal integration include but are not limited to
pharmaceuticals, ancestral cells, proteins, and cell parts of a
human tooth.
[0201] The meaning of "ancestral cells" shall include but shall not
be limited to multi-potent and stem cells, as such cells have the
ability to further differentiate.
[0202] The meaning of "cell parts of a human tooth" shall include
but shall not be limited to PDL-fibroblasts, non-PDL-fibroblasts,
cementoblasts, osteoblasts and ancestral cells, having the ability
to differentiate into PDL-fibroblasts, non-PDL-fibroblasts,
cementoblasts and osteoblasts. "PDL" shall mean in this context
"periodontal ligament".
[0203] Glass ionomer cement is composed of a
calcium-alumino-silicate glass powder and an aqueous solution of an
acrylic acid homo- or co-polymer. It is a biocompatible material
widely used for tooth restorations and provides good adhesion to
the ligament. Resin-modified glass ionomer cement can be
light-cured. The light activates a catalyst in the cement that
causes it to cure in seconds.
[0204] After curing, the artificial tooth is implanted and
integrated into the existing periodontal tissue formation of that
lower left incisor of the patient and fixed substantially into the
same position and inclination of the extracted tooth by being
bonded with light curing resin strips to the adjacent teeth.
[0205] Another option is coating the portion to be implanted with
Ca(OH)2-cement. This is a well known substance in dentistry also
used to fill root canals. After setting, EMDOGAIN (Institut
Straumann AG, Basel, Switzerland), a substance containing the
enamel matrix protein Amelogenin, will be applied. EMDOGAIN is
resorbed naturally during the normal healing process, leaving only
a residue of enamel matrix protein on the coated surface. This
natural and insoluble surface layer encourages the population of
cementum-forming cells from the surrounding tissues. Other proteins
aiding the growth of dentin, bone or tissue structures like bone
morphogenetic protein (BMP), dentin matrix protein (DMP),
platelet-derived growth factor (PDGF) and/or or other tissue growth
stimulating proteins may be applied or otherwise used additionally
or instead in order to facilitate integration, healing, and rebuild
of the periodontal ligament. The newly created surface also
functions as an interface between the tooth and the surrounding
tissues, preventing down-growth of the epithelial tissues. Again,
instead of coating, all the aforementioned substances can be
applied by other means including but not limited to adjunction and
injection. It may be advisable to prescribe antibiotic
pharmaceuticals to reduce the infection risk during the healing
process. In another embodiment of the invention, the root
portion(s) of the prosthesis are coated with a drug releasing
surface that releases the aforementioned proteins and anti-biotic
and other inflammation reducing substances or any combination
thereof over time. The drug releasing surfaces can be made, for
example, of materials that can be completely resorbed and replaced
by natural bone structure or soft tissue.
[0206] Especially in the context of periodontal integration, it
might be advisable to utilize an absorbable collagen membrane to
separate the faster gum growth from the healing process of the
periodontal ligament.
[0207] In another embodiment, an undersized customized root
representation of a ceramic prosthesis is coated with a thin layer
of mineral trioxide aggregate (ProRoot MTA, Dentsply) while
potential socket irregularities are prepared with calcium sulphate
(Capset, Lifecore Biomedical) in order to promote the selective
formation of new periodontal tissue (i.e., cementum, periodontal
ligament, Sharpey's fibers and alveolar bone) and to build a
barrier against an overgrowth by gingival tissue. The thickness of
the coating layer should match the undersizing of the root shape
and would preferably be chosen to be about 0.2 to 0.3 mm. It would
furthermore be advantageous to insert the prosthesis into the
socket as soon as possible, but no more than 24 hours (see
respective reference re: Spouge, Oral Pathology, Mosby, Saint
Louis, 1973 above), after extraction.
[0208] Periodontal integration (FIG. 10) has the advantage that the
anchoring of the prosthesis (200) is not stiff as with
osseointegrated implants, but shows the elasticity of the natural
tooth. The ligaments (1040) are providing support to the teeth in a
viscoelastic manner. Furthermore, forces applied to the tooth. and
thus, to the ligaments, create tension which is actually the
stimulus for bone growth. Another function of the periodontal
ligaments is to serve as a method for sensation. To support
periodontal integration, the implantation of the prostheses should
be performed shortly after extraction of the natural tooth,
preferably not more than 24 hours after extraction. A key to
success is the preservation of cellular vitality in the periodontal
ligament and performing the extraction in a surgical environment
under conditions of asepsis. Further below, other embodiments of
the invention are disclosed providing instant replacement of the
natural tooth.
[0209] In another embodiment, suitable pre-determined generic root
shapes can be selected and employed for fabricating the portion of
the implant to be osseointegrated or integrated into the
periodontal ligament. A variety of generic shapes may be stored on
a computer-readable media and accessed by the CAD/CAM system.
[0210] Another product that is helpful in adapting an implant into
the extraction socket is Atrisorb (CollaGenex Pharmaceuticals,
Inc., Newtown, Pa.). It helps regrow healthy bone and soft tissues
and forms a barrier creating a space in which tissue can grow.
Atrisorb is applied as a gel and forms a barrier membrane when
sprayed with sterile water. It maintains structural integrity for
approximately six months. Complete bioabsorption is achieved within
nine to twelve months.
[0211] In order to assure that only the desired portions of the
prosthesis are adopted by the periodontal tissue, other portions,
like the surface intended to carry the crown later to be attached
to the implant, may be covered with a substance preventing such
adoption. Silver is, for instance a biocompatible material suitable
for that purpose. The Fraunhofer Institute for Manufacturing
Technology and Applied Materials Research (IFAM) has developed a
nano-composite plasma coating technology that can be used for
applying a thin layer containing silver.
[0212] In yet another embodiment, the crown of the extracted tooth
or the tooth to be extracted is not only subject to 3D imaging, but
additional color data are obtained. Depending on the scanning
method, color data can already be contained in the scan data, or a
separate imaging is performed to record the color of the crown. It
is possible to obtain a uniform overall color representing the
average color of the crown, or alternatively, different shadings
for different portions of the crown can be recorded. Based on the
color data, the color of the crown can be adapted to the color of
the original tooth. The lab technician manufacturing an artificial
crown can, for instance, be provided with the color data and select
the most appropriate color for the prosthesis. If a complete
prosthesis is manufactured using CAM methods, a material best
fitting the original color can be used, or a coating can be
selected that matches the original color.
[0213] In another embodiment, no fixture is used to manufacture the
second portion of the artificial tooth. Instead, dedicated feature
elements can be added to the shape of the root, such as small holes
or posts sticking out, allowing for precise positioning of the
artificial tooth for the second step, which is manufacturing the
crown portion. These dedicated features can be removed or closed
after the complete tooth has been fabricated.
[0214] In yet another embodiment, a rapid prototyping process is
used for fabricating a prosthesis from hybrid materials. The rapid
prototyping process may build the prosthesis layer-by-layer. For
instance, a powdery layer of a substance can be applied on top a
workpiece, and then portions of the new layer are hardened by a
controlled laser beam, while the other unhardened portions are
later be removed. In this manner, different substances having
different properties (stiffness, hardness, biological properties
etc.) can be applied and therefore different portions of the
workpiece be made from different materials. In one embodiment, the
crown is made from a material different from the one used for the
root. In yet another embodiment, the portions representing dentine
are made from a material different from the one used for the
portions representing enamel.
[0215] In another embodiment, the three-dimensional data used to
fabricate the dental prosthesis is not acquired from an extracted
tooth, but rather, obtained intra-orally with the tooth to be
replaced still in place. The advantage of this embodiment is that
the complete digital preparation and also the manufacturing steps
of the artificial replacement can be performed prior to the
extraction. Only when the artificial tooth or segment to be
implanted is ready for insertion, the original tooth is extracted.
Immediately after extraction, the artificial tooth can be
implanted. This contributes to a better healing of the trauma.
[0216] FIG. 3 outlines the process steps. A CT scan (steps C, Q) is
made of the dentition of the patient. The resulting 3D data (D) is
imported into CAD software and displayed to the operator (step E).
The shape is modified and optimized as needed (step F). The
resulting 3D data is converted into IGES format and exported (step
H) to a CAM system for fabricating the prosthesis (step I). The
process may include coating the finished prosthesis (step J) with a
substance promoting bone ingrowth (step K). Only after the
prosthesis is ready for insertion, is the natural tooth extracted
(step G), and the implant is placed into the extraction socket
(step L). It should be noted that although FIG. 3 contemplates
possibly interaction with an operator, one skilled in the art would
readily appreciate that this functionality may be fully
automated.
[0217] A NewTom 3G-MF12 Cone Beam CT (NewTom Deutschland AG,
Marburg, Germany) can be used to acquire the imaging data. The
accuracy of the measurement data will be better than 0.2 mm and
therefore highly sufficient for the process. A spline CT with a
small envelope dedicated to dentistry like the Morita can deliver
3D data with even better resolution.
[0218] The in-vivo structures represented by CT raw data (for
example, in DICOM format) can be analyzed by voxel-based software
platforms (IVS Solutions AG; Germany) where 3D objects are
separated to be distinguished from "grey scale" data. In another
embodiment, adaptable algorithms can be used to analyze the dental
structures of interest. Such adaptable algorithms can use known
data of for example, generic shapes to drive the adoption of "grey
scale" filters.
[0219] Further, methods for intra-oral imaging include but are not
limited to CT, CBCT, MRT, ultra sound, active triangulation,
passive triangulation, confocal scanning, and TOF (Time-of-Flight).
The anatomical structures obtained by intra-oral imaging include
but are not limited to periodontal structure, the alveolus, and the
jaw bone of the patient.
[0220] Using intra-oral 3D imaging, it is even possible to perform
a scan of a patient long in advance and to file the personal
imaging data of the dentition of the patient. In case of an injury
or accident where teeth get lost or busted or are not available for
a scan for any other reason, a fabrication of individual prostheses
can be initiated immediately, using the previously collected
imaging data.
[0221] Instead of 3D imaging and digitally processing imaging data,
copy milling or copy grinding from the original tooth or parts or
the tooth can be performed. The root can also be shaped according
to an impression made directly from the alveolus of the extracted
teeth as shown in FIG. 14, using a specialized material or using
standard impression materials separated from the surface
(periodontal ligament or bone) of the alveolus (500) by a very thin
film of plastic or another material suitable for the purpose.
Alternatively an impression can be taken from the extracted tooth.
Laboratory methods for fabricating dental prostheses basing on
impressions are readily available. These methods mostly involve
using casting processes or employing light curing or chemical
curing processes where monomer components are polymerized to
molecular networks. Further, methods of fabricating a substantial
copy of the original tooth include but are not limited to
depositing, sintering, 3D printing, molding, curing, grinding and
milling. The ongoing progresses made in rapid prototyping, that is,
fabricating individual parts directly basing on digital data, will
strongly contribute to this invention.
[0222] In some cases the shape of the original roots will present
difficulties on the insertion of the artificial replacement. In
such cases, a proper modification and optimization of the shape of
the artificial root according to FIG. 23 is applicable. In other
cases, the root of the natural tooth may be suffering from partial
root loss due to root resorption or a surgical procedure. In these
cases, the root of the replacement may be adapted to the extraction
socket as demonstrated in FIG. 24. For example, the customized
portion includes a substantial copy of at least 60% of the root
shape of the natural tooth while the other portion of the
artificial root is modified as described herein. In other cases,
the size of the socket may have been reduced over time due to root
resorption as displayed in FIG. 25. The size reduction has occurred
in areas (17000). In such cases, it is advantageous to enhance
anchoring by surgically enlarging the socket and to adapt the root
of the artificial tooth to the enlarged socket. SolidWorks is a
suitable CAD software to alter the shape of the implant with
respect to the original imaging data.
[0223] There are more reasons to modify the shape of the implant
with respect to the original root. To ease insertion into the
extraction socket, the shape of the implant may be slightly
undersized as shown in FIG. 22. MAGICS provides a functionality
allowing for a simple reduction of the overall size of a body. On
the contrary, an oversized artificial root may be desirable in
order to receive a very tight mechanical fit in the extraction
socket to promote osseointegration as displayed in FIG. 17. This
can also easily be achieved with MAGICS. This software has a couple
of helpful features that have originally been developed to optimize
plastic parts for injection molding, but turned out to be useful
also for the processes of various embodiments of this
invention.
[0224] In an exemplary embodiment, the root portion of the
prosthesis adjacent to the bone socket of the extraction site
substantially mimics either the root shape of the non-functional
tooth to be replaced or the three-dimensional shape of the bone
socket or any combination thereof, but will be dimensioned not to
exceed the shape of the bone socket in order to avoid a conflict
when positioning the prosthesis clinically in the pre-defined
position and inclination. In a further embodiment, measurement
and/or manufacturing tolerances are considered undersizing the root
portion adjacent the bone socket in its design. Manufacturing
tolerances are to be estimated between 10 and 50 micrometers.
Measurement tolerances are to be estimated between 20 and 400
micrometers.
[0225] In yet another embodiment of the invention, original
portions of the natural tooth will be integrated into the implant.
Especially portions of the root still being covered with cement can
greatly improve adoption into the ligaments of the extraction
socket. On order to integrate those natural portions, they will be
cleaned and prepared for imaging as described further above. The
resulting 3D imaging data will be imported into MAGICS and
processed like the data of a complete tooth. The three-dimensional
virtual body will then be placed at the proper location with
respect to the virtual body representing the shape of the implant
to be produced. Using Boolean functions of MAGICS, the body
representing the natural portion(s) of the tooth will be subtracted
from the body representing the implant, thus, creating a cavity in
the implant having the exact size and shape of the natural
portion(s) of the tooth to be integrated into the implant. After
the implant has been fabricated and processed, the natural portions
of the tooth are cemented into the implant.
[0226] In yet another embodiment of the invention, firm anchoring
of the implant is achieved by expanding the portion being located
in the extraction socket in order to support osseointegration and
improve physical stability after the implantation. By expanding the
implanted portion, forces are applied to the alveolus or bone. In
this embodiment, the artificial root is shaped to form an expansion
anchor. Expansion can be achieved by either using a material
changing its shape due to temperature changes after insertion like
SMA (shape memory alloy) or by using a material like shape memory
polymers activated by electromagnetic radiation. Expansion can also
be achieved mechanically by placing a dowel inside the artificial
root. This is demonstrated in FIGS. 13 and 15. The root portion of
the implant is slotted, thus forming posts or wings (12000) and
made from a material providing sufficient elasticity in conjunction
with the slots. When screw (12020) is inserted into dowel (12010),
the posts are pressed against the walls of the extraction socket.
The crown (12030) is attached to the implant after insertion, using
standard procedures known in prior art. FIG. 16 displays such an
implant located in an extraction socket where voids have been
filled with a substance (13000) promoting bone growth like Bioplant
or CERASORB. In FIG. 35 another embodiment is displayed. No dowel
is used, but instead the thread is conical. When screw (12020) is
inserted into the conical thread, the wings (12000) are accordingly
expanded and pressed firmly against the extraction socket, as
demonstrated in FIG. 36. Alternatively, the initial pressure
supporting the fast integration into the bone may be performed by
for example, three oversized small grooves positioned on the outer
surface parallel to the longitudinal axis of the root causing
pressure when the artificial root will be inserted.
[0227] To achieve a long living prosthesis, the size and the shape
of the root and the socket needs to be appropriate to enable solid
anchorage in the bone. If, for example, a root is too small to
absorb the normal chewing forces it may be necessary to expand the
size of the socket before designing and manufacturing the
customized root. Other patients may not have enough bone material,
so that the thickness of the bone gingivally and labially is not
sufficient for the anchorage of an implant. In such a case, the
root may be shaped like a clamp so that the corticalis is used for
the anchorage. This approach is known as the "juxtaosseous" method
(the implant adapts to the bone and not the bone to the implant).
If an appropriate material like titanium in combination with
biological ossifying substance is used, the bone adapts to the
implant and so the implant becomes an osseointegrated implant. For
abutments, this is already successfully being used by the San
Babila Day Hospital in Italy. Even more solidity can be achieved by
a "multi-legged" root shape combining an artificial root and clamp
shaped outer part for the adaptation to the corticalis. This
approach significantly increases the stability of the anchorage
because no hollow or less stabile areas remain in the bone. If
crown and root are manufactured as one part, the crown may be
coated with an enamel-colored layer or multiple layers for
aesthetic reasons. Such layer(s) can be, for example, translucent
to a certain extent. During the healing process, appropriate
measures need to be put in place to avoid early exposure of the
implant to forces (bite bumpers, partials positioners, etc.).
[0228] The invention is not limited to the replacement of a single
tooth. It is possible to manufacture dental bridges, whereby the
lateral teeth have root features that can readily be implanted into
an existing socket. Conventional dental bridges (15000) as
displayed in FIG. 20 are cemented onto natural teeth with the crown
being grinded down (15020) or onto conventional implants (600).
According to this invention, the natural sockets (6000) can be used
as shown in FIG. 21 for attaching the bridge (16000), with the
adjacent teeth (100) staying healthy and complete. It is also
possible to fabricate a partial prosthesis to be implanted into the
natural socket, said prosthesis being the anchor for a later
installment of a dental bridge. This embodiment is especially
useful in cases where one of the two lateral supports of the bridge
is already present, and the bridge therefore needs to be
cemented.
[0229] According to various embodiments of the present invention,
due to the ability of the suggested manufacturing processes, a
respective embodiment of the invention allow the fabrication of
prostheses representing crowns, roots, bridges, segments or any
combination thereof, and also the entirety of a dentition.
[0230] In another embodiment, off-the-shelf abutments can be
integrated into the artificial root using the intended connection
method recommended by the manufacturer like screwing them into the
artificial root with or without drilling a hole, clicking them onto
a counter shape or others.
[0231] In yet another embodiment, the components will be molded
directly into the artificial root.
[0232] In yet another embodiment, the artificial root will comprise
a feature on its occlusal-facing surface shaped in a way that it
allows for assembly of a conventional veneer or a pre-manufactured
veneer or crown to the root. The occlusal-facing surface can also
be shaped to provide an interlocking connection to the crown as
shown in FIG. 12. The occlusal surface can also have all kinds of
connecting features (11000) symbolized in FIG. 11 to allow for
attachment of a crown (12050).
[0233] In yet another embodiment as shown in FIG. 18, the
extraction socket will be filled with a bone promoting substance
(9040), and a connection element (11000) for the root is embedded
into the bone promoting substance. FIG. 19 shows the artificial
crown attached to the connection element of FIG. 18 after the bone
promoting substance has been replaced by newly grown bone
(9090).
[0234] In another embodiment, the time needed for the adoption into
the periodontal ligament will be reduced and/or the strength and/or
the life-time of the connection to the surface of the artificial
root will be optimized by increasing the surface by sandblasting,
adding a mesh or other suitable means, and/or adding pharmaceutics
or other substances supporting the integration of the chosen
material of the artificial root into the periodontal ligament such
as, for example, the protein amelogenin. These pharmaceutics can be
applied by conventional or state-of-the-art methods like dry or
liquids suspensions to be painted onto the artificial roots before
integration, or by injection with a hypodermic needle or
intra-orally through pills. Also, ancestral cells may be used to
support the rebuilding of the periodontal ligament.
[0235] Membrane techniques may be used to protect the area
dedicated to the relatively slow growing periodontal ligaments from
the fast growing gingival epithelium.
[0236] In another embodiment, decreasing the time needed for the
osseointegration and/or increasing the strength and/or the
life-time of the connection to the surface of the artificial root
can be achieved by increasing the surface by sandblasting, adding a
mesh or other suitable means, and/or adding pharmaceutics
supporting the integration of the chosen material of the artificial
root into the bone. These pharmaceutics can be applied by
conventional or state-of-the-art methods like dry or liquid
suspensions to be painted onto the artificial roots before
integration, or by injection with a hypodermic needle or
intra-orally through pill and/or ray treatment.
[0237] In another embodiment, the shape of the artificial root will
not completely reflect the shape of the root to be replaced. In
order to strengthen the connection with the periodontal ligament or
the bone, the shape will be modified. If, for instance, the three
roots of a molar are located very close to each other, the three
roots will be replaced by only one root which will comprise parts
of the original shape of the three original roots.
[0238] There is a lot of software readily available on the market
that allows for easy and intuitive modification of 3D shapes. Both
previously mentioned programs: MAGICS and SolidWorks are suitable
for this task.
[0239] In another embodiment, the closure of remaining gaps between
the artificial root and the socket used for implantation can be
accelerated by suitable pharmaceutics and/or ray treatment.
[0240] In yet another embodiment, the prosthesis is an assembly of
one or more parts where the interfaces between such parts are
sealed in order to provide a barrier against bacteria infiltration.
The sealing can include, for example, a labyrinth feature.
[0241] In another embodiment, the root portion of the prosthesis is
an assembly that is configured to extend one or more barbed hooks
which in a favorable embodiment are each connected to the root body
with a hinge and activated by a leave spring.
[0242] Conventional two-piece implants as shown in FIG. 37 consist
of an implant (600) to be osseointegrated that includes an abutment
portion and an artificial crown (12030). Conventional three-piece
implants as shown FIG. 38 consist of an implant (600) to be
osseointegrated, an abutment (19000), and an artificial crown
(12030). In either configuration these conventional implants (600)
and the abutment (19000) are mass produced and have a generic
shape. The artificial crown (12030) will be made in a dental
laboratory based on impressions of the embedding dental situation
which includes the abutment portion of the implant after
integration into the dental anatomy of the patient. In other words,
the crown will be made based on the geometrical relation between
the implant and the abutment (portion) after placement.
[0243] In contrast, the prosthesis according to an embodiment of
the present invention is manufactured in all its parts or as a
single piece in its entirety before being integrated into the
dental anatomy of the patient of interest. FIG. 39, for example,
shows a tooth-shaped one-piece prosthesis having an integrated root
portion and an integrated crown portion (200). The prosthesis (200)
can be shaped with or without a custom shaped torus (20000) that
circumvents the prosthesis in a height of, for example, 0.5 mm
below the line of gingiva (1030). The torus (20000) builds a
barrier against in-growth of the gingival tissue. In case the
prosthesis (200) is configured for osseointegration, the cavity in
the bone (1060) is virtually sealed, and osseointegration will take
place without being disturbed by isolating lobes of gingival tissue
growing between the prosthesis and the cavity. In case the
prosthesis (200) is configured for periodontal integration, the gap
between the prosthesis and the extraction socket is sealed against
fast growth of gingival tissue, so that the integration into the
periodontal ligament structures, having a reduced growth rate in
comparison, is protected.
[0244] In yet another embodiment, the prosthesis is an assembly (as
shown for example, in FIGS. 5, 6, 8, 11, 12, 13, 15, 16, 18, 19,
31, 34, 35, 36, and 45) of two or more parts. The parts are, for
example, glued, sintered, mounted by pressure, and/or screwed to
each other. The interface between connecting parts needs to be
sealed against bacteria infiltration. Special sealing concepts like
O-ring sealing and labyrinth sealing may apply.
[0245] In another embodiment as shown in FIG. 40, the prosthesis
(400) has a sealing feature (21000), which is circumventing or
partially placed between the crown portion and the root portion of
the prosthesis (400). The sealing feature (21000) is either simply
an indent or a labyrinth feature that builds the interface between
the material of the prosthesis and the gingiva (1030). The
respective interface seals the structure between the prosthesis and
the extraction socket against bacteria infiltration in order to
gain long-term stability and to avoid pockets.
[0246] In another embodiment, the crown portion of a prosthesis is
fabricated in an undersized shape compared to the final shape of
the crown. Single or multiple layers of translucent ceramics are
added in a laboratory process to gain esthetic performance compared
to the appearance of a natural tooth. FIG. 41, for example, is a
single tooth prosthesis having an undersized crown shape (200) and
a build-up of several ceramic layers (22000). It is also possible
to use other esthetic materials having one or more than one layer.
In another embodiment, the build-up (22000) is, for example, made
of elastic materials (like an elastic cover) in order to soften
early contacts and foster in this way the healing process after
integrating the prosthesis.
[0247] In yet another embodiment, a prosthesis is at least
partially made of one of the following: titanium, titanium alloy
that consists of more than about 60% of titanium, cement, zirconium
oxide, ceramics, synthetics, elastics, plastics, stainless steel,
glasiomer cement, resin-ionomer cement, hybrid-ionomer cement,
resin-enforced cement, and acrylic based photopolymer, or any
combination thereof. In a further improvement, the prosthesis
includes a drug releasing surface, releasing over time medical
substances. Such substances include, for example, one of the
following: Antibiotic or other infection suppressing
pharmaceuticals, growth promoting substances (for example,
ancestral cells, proteins, and cell parts of a human or animal
tooth) or any combination thereof. FIG. 42 is, for example, a
single-tooth prosthesis (200) having a drug releasing surface
(23000) covering at least a portion of the root part of the
prosthesis (200).
[0248] In yet another embodiment, a prosthesis is fabricated based
on imaging data of the patients dental anatomy. The imaging data
includes three-dimensional representations of one tooth or two or
more teeth. Each tooth includes a crown portion and root portion.
The imaging data can be made either prior to or after extraction of
the tooth or teeth to be replaced. The imaging data can include
in-vivo data or data made in-vitro from one tooth or two or more
teeth after extraction. Other imaging data are derived from
physical impressions made of a dental anatomy. Dental anatomy
includes the occlusion, the articulation, the geometrical (spatial)
relationship between the teeth within one arch or between upper and
lower arch of a patient, or parts thereof. Dental anatomy also
includes the structures holding the tooth/teeth which include soft
tissue structures and bone structures and any combination thereof.
Imaging data can include two dimensional representations (for
example, X-ray films, facial photos) or three-dimensional
representations (like CT or MRT data). Imaging data can be any
portion of the aforementioned data and/or any combination thereof.
All these imaging data can be merged, overlaid and combined to
derive shape data of a design of a prosthesis.
[0249] In another embodiment, FIG. 43 is a single-tooth prosthesis
(400), having a manufactured crown portion and a manufactured root
portion. The shape of each is derived, for example, from in-vivo
imaging data prior to the extraction of the tooth to be replaced.
By extraction of said tooth to be replaced, the extraction void
(900) was created. The adjacent teeth (mesial and distal of the
extraction socket) are healthy natural teeth (300). The extraction
was indicated, for example, due to a serious porosity of the root
of the extracted tooth. The extraction socket was partially
curetted by the doctor of record, removing damaged soft tissue.
Antibiotic tablets are given orally to the patient in advance to
suppress the inflammation and to avoid additional infection as a
result of the clinical trauma of removing the tooth. The crown and
the root shape are derived from the imaging data. In addition the
crown shape of the adjacent teeth (300) and a desired position and
inclination of the prosthesis are derived from the imaging data.
Based on all this data a custom-shaped splint (24000) is designed
and fabricated. The splint is used to position and orient the
prosthesis (400) in the dental structure (1030) building the
extraction void in geometrical relation to the adjacent teeth
(300). Being held in the desired position and orientation, the
custom-shaped splint (24000) is glued with adhesive means to the
prosthesis (400) and the adjacent teeth (300). For example, light
curing adhesives are used in that context. Finally, the prosthesis
(400) is fixated in its desired position and the crown portion is
thereby integrated into the occlusion and articulation of the
patients dental anatomy. Slight corrections performed by the doctor
of record with a high-speed rotating instrument may be necessary to
optimize the occlusal contact points. The prosthesis can be
immediately loaded by the patient for the day-to-day use of
mastication. The custom splint glued to a prosthesis and adjacent
teeth or other dental structures provides the primary stability
while either the periodontal integration or the osseointegration
takes place.
[0250] Although shown in FIG. 43, not to interfere with the
occlusion of the upper and lower dentition of the patient receiving
the appliance when inserted, the splint can also have an extension
that covers, for example, not only the lingual crown portions of
the prosthesis and of the adjacent teeth, but includes also incisal
edges in the event anterior teeth are affected or cusps in the
event posterior teeth are affected. In a further embodiment,
significant occlusal surfaces of the teeth of interest can also be
covered by the splint. In an exemplary embodiment, the design and
the fabrication of the splint may include such contours covering
additional surfaces or portions thereof to enable better
positioning of the prosthesis, with such contours to be physically
removed after bonding in the patient's mouth by the doctor of
record.
[0251] In the context of the aforementioned custom splint, FIG. 44
shows, for example, the process steps of fabricating such a
prosthesis and such a splint. A partial silicone impression is
taken from the mouth of the patient representing the dental
(occlusal) crown anatomy in the neighborhood where a prosthesis
will be integrated (step S). The impression is scanned and
three-dimensional STL data of the shape are derived representing
the crown geometry of the tooth to be extracted, the crown geometry
of the adjacent teeth, and the geometrical relation between those
crown data (step T). Additionally, the patient's dental anatomy is
imaged with a computed tomography device (step C). Computed
tomography (CT) is a medical imaging method employing tomography
where digital geometry processing is used to generate a
three-dimensional image of the internals of an object from a large
series of two-dimensional X-ray images taken around a single axis
of rotation. The layered grey scale X-ray data in digitized format
are then computer analyzed and voxel as well as three-dimensional
STL data are derived representing the dental anatomy of the patient
(step Q). All aforementioned STL data can be scaled, merged and/or
combined to generate accurate three-dimensional shape data from
tooth to be replaced and the adjacent dental anatomy (step E).
Boolean algorithms can be used to generate combined data of
high-quality. In a first design of the prosthesis, its position and
orientation within the adjacent dental anatomy, especially in
relation to the crown portions of the adjacent teeth, and a second
design of a custom shaped splint that includes shape portions of
the crown of the prosthesis and of the crowns of the adjacent
teeth, are derived. The first and the second design may be modified
and optimized (step F). This can be done automatically or
interactively by having a technician operating the respective
computer equipment. Computer numerical control data (CNC), for
example, in IGES format for computer aided manufacturing (CAD)
devices are derived from the final three-dimensional design data
(step H). Usually rapid prototyping equipment is having the
aforementioned step already integrated. The prosthesis is
fabricated in response to the IGES data, for example, by a CAM
high-speed milling/grinding machine (step I and J). Additionally,
the rapid prototyping machine, such as, for example, a
layer-by-layer wax printing machine, is fabricating a
three-dimensional wax representation (sample) from the
three-dimensional design data (step U). The sample is prepared and
embedded for lost wax investment casting, whereby the wax sample is
burned out and the investment mould is filled with liquid precious
metal (e.g., dental gold alloy; step V). After cooling down to room
temperature, the embedding material is removed, the runner is
cut-off and the splint is polished and surface prepped for bonding
(step W). It should be noted that while FIG. 44 contemplates
possibly interaction with an operator, one skilled in the art would
readily appreciate that certain steps are combined, further
differentiated, and that this functionality may be partially or
fully automated.
[0252] In yet another embodiment, a prosthesis is segmented and
such segments are fabricated using different manufacturing
technologies. FIG. 45 shows the process steps of receiving design
data of a prosthesis in STL format (step E), separating portions in
a computer aided design (CAD) process (step X and Y), deriving
computer numerical control (CNC) data and utilizing computer aided
manufacturing (CAM) machinery, for example, high-speed
milling/grinding machines (step I) to fabricate the respective
portions (step Z and AA) in response to the CNC data. The separated
portions are combined to build the prosthesis (step BB).
[0253] A specific implementation of the processes of FIG. 45 is
described hereinafter: A first segmented design portion, for
example, the crown portion of the prosthesis (step X) is not
fabricated directly. Rather an inverse shape (for example, the
negative representation of the crown shape) is cut (step I) to
build a separate work piece, for example, a mould (step Z). The
second segmented design portion (step Y), for example, the root
portion of the prosthesis, is cut as a positive representation is
cut from a workpiece (for example, consisting of zirconium oxide)
(step I) to build a portion of the prosthesis itself (step AA). The
positive part of the prosthesis (e.g., the root portion) is
combined with the negative representation (e.g., the mould carrying
the inverse crown shape) to fabricate the missing portion of the
prosthesis according to the first segmented design portion (step
BB). In a more particular implementation, for example, the mould
"Z" is made of a transparent material (acryl glass,
polymethyl-methacrylate), prepared with a separating layer
(silicone spray), filled with nano-composite usually used for crown
restorations (BISICO, Germany), the root portion "AA" is placed in
the designed position and inclination to conform to the overall
design of the prosthesis and the composite is cured in a UV-light
chamber widely used in dental laboratories (step BB).
[0254] In another embodiment, the custom splint is fabricated in an
indirect method for example, by lost-wax investment casting. FIG.
46 shows the process steps of fabricating the custom splint from
design data, and fabricating a model of the splint by rapid
prototyping, building a mould around the splint, burning out the
model and casting the splint by investment casting. As shown in
FIG. 46, the process starts with receiving the 3D design data of a
custom splint (step CC), then a sample part of the custom splint is
fabricated using stereo-lithography conforming to the design data
(step DD). The sample part is embedded (step EE) in, for example, a
gypsum-bound investment material (like Cera Fina, Whip Mix,
U.S.A.). The investment mould is heated and the material of the
sample part is burnt out (step FF). The mould filled by vacuum or
centrifugal casting with liquid precious alloy (for example,
Argenco 42 Type IV extra hard, The Argon Corporation, U.S.A.--step
GG), and the embedding mass is removed (step HH). The casting
runner is cut from the custom splint (step II), and the custom
split is polished and prepared for bonding (step JJ). It should be
noted that while FIG. 44 contemplates possible interaction with an
operator, one skilled in the art would readily appreciate that
certain steps can be combined, or further differentiated, and that
this functionality may be partially or fully automated.
Alternatively to the precious metal, the investment casting can be
done with stainless steel or other suitable non-precious dental
alloy known to those skilled in the art.
[0255] In yet another embodiment, the custom splint is perforated
or prepared with retention features on the bonding surface (like a
mesh) for better light curing capabilities and better bonding
strength.
[0256] In another embodiment, the clinical process integrating the
prosthesis is performed as shown in FIG. 47. The process begins by
preparing the extraction socket for insertion, which may include
rinsing (step KK), micro-etching (sandblasting) and/or etch (e.g.,
phosphoric acid) bonding the surface of prosthesis (step LL),
micro-etching (sandblasting) and/or etch (e.g., phosphoric acid)
bonding surface of the adjacent teeth or other dental structures
(step MM). Once the extraction socket is prepared, the prosthesis
is inserted (step NN), applying light curing adhesive to all
bonding surfaces (step OO). The prosthesis is then positioned and
oriented in the desired geometrical relation to the adjacent teeth
or other dental anatomy of interest using the custom splint as a
positioning aid or guide (step PP). The prosthesis and the splint
are held firmly in position while the adhesive is light cured with
a dental UV-light curing device (step QQ) in order to fixate the
prosthesis in its desired position. Excess adhesive is removed
(step RR), and a final check and adjust--if necessary--of the
occlusion and articulation of the patient in respect to the contact
situation of the prosthesis to the teeth or other dental structures
of the opponent arch is performed (step SS).
[0257] The immediate implantation of a manufactured prosthesis
designed and fabricated based on in-vivo imaging data (made prior
to the extraction of one or more tooth/teeth of interest) directly
after extraction may be challenged by non-healthy developments of
bone or soft tissue in the extraction cavity. FIG. 48 shows the
process steps of clinically preparing an extraction socket by
removing decayed soft tissue (26000) and/or decayed bone (25000)
with a laser technology based device (27000). The high water
content of decayed structures is more absorbent for the laser light
energy than healthy structures so that the decayed areas can be
easily removed without serious collateral damage of adjacent
healthy structures of the dental anatomy. The healing process is
this way combined with the integration process of the prosthesis.
Negative side effects of bone resorption are reduced by the
immediate integration of a prosthesis according to an embodiment of
this invention. The immediate implementation can be combined with
both prosthesis configured for osseointegration and with prosthesis
configured for periodontal integration.
[0258] In yet another embodiment, the healing and integration of a
prosthesis is facilitated after insertion by using ultrasonic or
other vibrations applied to the prosthesis by special dental
devices.
[0259] The integration of the all prosthesis described herein can
be facilitated and actually accelerated by techniques of surface
coating based on tissue engineering. FIG. 49 shows the process
steps of taking autologous soft tissue cells from the patient (step
TT), culturing such soft tissue cells in an in-vitro assay system
(step UU), and apply such cells with or without other tissue
engineering materials to the root portion of the prosthesis (step
VV). FIG. 50 shows the process steps of taking autologous bone
cells from the patient (step TT), culturing such soft bone cells in
an in-vitro assay system (step XX), and apply such cells with or
without other tissue engineering materials to the root portion of
the prosthesis (step VV). In both aforementioned scenarios the
soft-tissue or bone structures are taken with a sharp instrument
(for example, an exenteration scoop like a Chalazion curette).
Other exenteration techniques may apply.
[0260] In another embodiment, human periodontal ligament (HPDL)
fibroblasts are used and a prosthesis according to other
embodiments of the invention is placed in tissue culture clusters,
an amount of 1 ml of HPDL fibroblast cell suspension is placed over
the root portion of the prosthesis and then placed into an
incubator at 37 degree C. and 100% humidity for 72 hours. With that
the cells of HPDL fibroblast are extending and attaching firmly to
the prosthesis surface by cytoplasmic extension of the lamellipodia
and microvilli to extend into porous (micro) surface
structures.
[0261] In yet another embodiment, stem cells can be used to produce
HPDL fibroblast or other acellular and cellular structures of the
human dental anatomy (like acellular and cellular cementum, which
is mineralized tissue covering the root dentin that serves to
anchor periodontal ligament fibers, cementoblast, which are cells
found on the surface of cementum being responsible for its
synthesis).
[0262] Alternatively, to the aforementioned use of autologous
material, human allogenic bone, root or tissue substances can be
used. Alternatively, to the use of human bio material tooth,
animal-derived bone or tissue material, for example, bovine cells
or even synthetic materials can be used for in the various process
steps of tissue engineering.
[0263] In yet another embodiment, the tissue engineering techniques
include the coating of the root portion(s) of the prosthesis with
collagen incorporating growth factor substance, for example,
platelet-derived growth factor (PDGF).
[0264] The aforementioned tissue engineering technologies may
employ in the aforementioned context living cells of various kinds
as engineering materials, like autologous cells, which are obtained
from the same individual to which they will be reimplanted, mouse
embryonic stem cells, allogenic cells which come from the body of a
donor of the same species, xenogenic cells which are isolated from
individuals of another species, syngeneic or isogenic cells which
are isolated from genetically identical organisms, such as twins,
clones, or highly inbred research animal models, primary cells from
an organism, secondary cells from a cell bank, and adult stem
cells. In this context, tissue engineering shall also include the
use of artificial structures capable of supporting
three-dimensional tissue formation, called scaffolds, of various
natural and synthetic, biodegradable and permanent materials (for
example, collagen and aliphatic polyesters), on which cells are
generally implanted or `seeded` into to allow cell attachment and
migration, to deliver and retain cells and biochemical factors, to
enable diffusion of vital cell nutrients and expressed products, or
to exert certain mechanical and biological influences to modify the
behavior of the cell phase, or any combination thereof.
[0265] Several figures and several process steps described therein
show a prosthesis or parts thereof (configured for example, as a
single tooth prosthesis) being manufactured and shaped from all
sides (for example, FIG. 1 part 200, FIG. 3 step J, FIG. 4 step J,
FIG. 5 step J, FIGS. 6, 7, 8, 9, 10, 11, 12, FIG. 13/15/16 part
12030 and part 12000, FIG. 17 part 900, FIG. 18 part 9040, FIG. 19
part 9090 and part 12050, FIG. 21 part 16000, FIG. 22, FIG. 31,
FIG. 34, FIGS. 35/36 part 12030 and part 12000, FIG. 39 part 200,
FIG. 40 part 400, FIG. 41 part 200 and part 200 including 22000,
FIG. 42 part 200 and part 200 including 23000, FIG. 43 part 400 and
part 24000, FIG. 44 step J and step U, FIG. 45 step I, Z and step
M, FIG. 46 step DD). FIG. 51 outlines the process steps. After a
design of such prosthesis is obtained and computer numerical
control (CNC) data are derived and converted for example, into the
IGES format and transferred to a CAM system for fabricating the
prosthesis (step I), the prosthesis is shaped, for example, in
regards to its root portion by milling one side of the workpiece
(with the result shown in step YY). The side of the workpiece being
already shaped will be temporarily embedded in adhesive materials
(step ZZ) turned (step ZZ') and fed, positioned, orientated and
clamped again into the CAM system (step I) to be shaped, for
example, in regards to its crown portion by milling the opponent
side to the aforementioned one side (with the result as shown in
step AAA). After dissolving or otherwise removing the adhesive
(shown in step ZZ and AAA) the all sides shaped workpiece is ready
for use or for the following process steps of surface polishing,
surface coating by, for example, plasma technologies, and tissue
engineering. Drug releasing surfaces can be applied or porous
surfaces may be loaded with growth hormones, proteins, antibiotic
or other substances. It should be noted that while FIG. 51
contemplates possibly interaction with an operator, one skilled in
the art would readily appreciate that this functionality may be
fully automated.
[0266] Skiba discloses in U.S. Pat. No. 7,813,806, which is
incorporated herein by reference, a surface coating and pattern of
spaced dissimilar materials, whereby the pattern is designed to
spontaneously produce electrical surface currents when brought into
contact with an electrically conducting solution, i.e., body
electrolytes, whereby the currents reducing infection and
contamination. For example, when a single mass of silver ink is
spaced from a single mass of zinc ink, a single voltaic cell is
created when an electrolytic solution electrically connects the
masses. In an exemplary embodiment, at least a root portion of the
dental prosthesis is coated with at least one dot of each of at
least two dissimilar materials. Such dots, have, for example, a
diameter of 1 mm and an average distance between its centers of 1.5
to 3 mm, and are painted on by bubble jet printing or by other
means, e.g., by hand painting. The materials are bio-compatible
and, for example, even resorbable over time, so that the current
producing effect when deployed for a period of time enhances the
integration and would healing.
[0267] For achieving a certain solidity and resistance of the
dental prosthesis, it is important to find a method for applying a
finishing process to the body or a component of a dental prosthesis
(200). It is known from US 2004/0168610 A1 that companies in the
dental industry, for example, Metoxit, supply ceramic blocks
treated by a hot isostatic process. However, it has not been
recognized until now by the inventors that dental implants,
abutments, prostheses or parts thereof are individualized in its
three-dimensional shape prior to a hot isostatic pressing.
[0268] In an exemplary embodiment, the process depicted in FIG. 52
reflects the hot isostatic pressing of a customized dental
prosthesis or its components. In the first step (AAAA), the body or
a component of the dental implant (24005) is spattered with a
metallic material (25000). Vacuum may be applied in the process of
spattering. In a second step (BBBB), a hot isostatic pressing
process is applied to the body or component (24005) with the
coating (25010). Thereby, certain cracks, flaws and imperfections
of the dental prosthesis body are compressed and eliminated. This
leads to a reduction of porosity of the ceramic material and allows
to compress the ceramic material close to its theoretical density.
The pressures are preferred of approx. 100 MPa (but may range up to
300 MPa); temperatures of approx. 1,400 degrees Celsius (but may
range up to 2,200 degrees Celsius). The hot isostatic pressing
process uses inert gas such as Argon gas as compression media. In a
further step (CCCC), the metallic coating (25000) is removed from
the cooled-down ceramic body or component (24005) of the dental
prosthesis. The removal of the coating (25000) is achieved by the
use of an etching process in which the coated body is placed in an
acidic liquid (25020) to totally remove the metallic coating. In an
alternative embodiment, the aforementioned process steps are
carried out on a body that consists of two or more parts. Those
parts may have different materials. The hot isostatic pressing
process will then facilitate an integration in the event of joints
between similar or identical materials or a diffusion bonding in
the event of joints between different materials. It is
alternatively possible to pre-sinter the ceramic components
gas-tight prior to the hot isostatic pressing in order to avoid
process step (AAAA) and (CCCC).
[0269] In a further embodiment, as shown in FIG. 53, a ceramic
porous coating (26000) is attached onto the outer surface (26010)
of the root portion body or a component of a dental prosthesis
(26005). A method and an arrangement for attaching a ceramic porous
coating to a dental prosthesis is known from US 2008/0213725 A1 in
which the company Noble Biocare describes the coating of a dental
prosthesis with a ceramic slurry. However, it has not been
recognized until now by the present inventors that similar surface
coating methods can be applied to dental implants, prosthesis, or
parts thereof after the surfaces are designed and
three-dimensionally shaped for a pre-identified patient. In the
first step (DDDD) depicted in FIG. 53, a ceramic slurry (26020) is
mixed comprising zirconia particles and wax particles or plastic
particles such as Polyethylene powder. In the next method step
(EEEE), the root portion body (10010) is dunked into the ceramic
slurry (26020) and pulled out with, e.g., a constant moving
velocity to receive a substantial uniform coating.
[0270] After pulling out the root portion body from the ceramic
slurry (26020), a ceramic slurry coating (26025) is attached on the
outer surface (26010) of the root portion body. In a further step
(FFFF), the whole assembly (26030) is first dried in an environment
with increased temperature. Then, the wax particles or
Polyethylene-powder is removed from the ceramic coating (26025) and
the coating particles are sintered together and connected by
sintering with the body material by applying high temperature to
the body. In another step, the connection between the root portion
body and the ceramic coating is achieved by sintering both parts
together and thereby forming one part. Thereby, a porous coating
(26000) is produced with a surface and scaffold that attract
biological tissue to form the desired periodontal integration of
the proposed dental implant into the patient's alveolus.
[0271] Another embodiment is shown in FIG. 54. Herein, the outer
surface of the root body portion (27010) of the body or a component
of a dental prosthesis dental prosthesis (27005) is infiltrated
with an alcoholic Hydroxylapatite-suspension (27020). In the first
step (GGGG), the Hydroxylapatite-suspension (27020) is mixed
composing Hydroxylapatite, ethanol, Polyvinylpyrrolidon as a binder
and Dolapix CE as a dispersant. In the second step (HHHH), the root
portion body (27010) is dunked into the Hydroxylapatite-suspension
and pulled out again. Thereby, the Hydroxylapatite-suspension
(27025) adhesively attaches to the root portion body. After
applying a burning procedure (JJJJ) on the whole body (27030), the
outer surface is coated with a biocompatible Hydroxylapatite-layer
(27000). Thereby, a coating is produced with a surface and scaffold
which attracts biological tissue to form the desired periodontal
integration of the proposed dental implant into the patient's
alveolus.
[0272] In a further embodiment as depicted in FIG. 55, the porous
outer surface (28000) in the area of the root portion body (26010)
of the dental prosthesis is created by applying laser light pulses
(28010) to the outer surface (26010) of the root portion body. Such
light pulses have a pulse-duration in the pico- or femto-seconds
range. Thereby, high energy pulses are created which are able to
break apart parts of the ceramic body and produce small cavities.
Barsch suggested in Quintessenz Zahntech 2009 35 (10): 1322-1332,
the treatment of zirconia implants with femto-second laser pulses
for enhancing the adherence. However, it has not been recognized
until now by the present inventors, that the root portion of dental
prostheses can be contoured individually for a pre-identified
patient by laser shaping. The laser shaping can be used to polish
certain surface portion, e.g., in the transgingival portion of the
prosthesis, and to contrarily create a roughness, e.g., in the root
portion to integrate with tissue, including a porous surface
condition. In a further embodiment, single laser shaped cavities
create the porous outer surface on the ceramic body. The laser
pulses are emitted from a laser entity being able to move in three
translation dimensions and two rotation dimensions (28030). Such a
setting is often called 5-axis laser. In yet another embodiment,
5-axis laser (28010) is used to shape the individual
three-dimensional contour of the prosthesis, at least
partially.
[0273] In an embodiment depicted in FIG. 56, the pico- or
femto-laser pulses (28010) can also be utilized to create rounded
edges (29000) on the porous outer surface on the root portion
(26010). Such rounded edges are of special interest since they
promote the biocompatibility and lead to an environment attracting
biological tissue.
[0274] In a further embodiment of the present invention shown in
FIG. 57, a porous outer surface (28000) in the area of the root
portion body (26010) of a dental prosthesis or implant is created
by a CNC milling or a CNC driven sinker erosive process
(30000).
[0275] In another embodiment shown in FIG. 58 of the fabrication
process of a prosthesis (52000) together with a splint, in a first
step (SSSSS) a physical impression of the denture of the patient is
taken, e.g., with silicon material. In a further step (TTTTT), the
crown geometry of the patient's crown is obtained from the denture
and translated to three-dimensional STL-data. Additionally, the
patient's dental anatomy is imaged with a computed tomography
device (CCCCC). The layered grey scale X-ray data in digitized form
(QQQQQ) are analyzed and voxels as well as three-dimensional
STL-data (DDDDD) are derived representing the anatomy of the
patient's denture. The grey scale X-ray (QQQQQ) data can be
represented in the format of the DICOM standard (DICOM: Digital
Imaging and Communications in Medicine). In a further step (EEEEE),
Boolean algorithms are used to generate combined data of high
quality of a virtual prosthesis. The data of the virtual prosthesis
are optimized (FFFFF), e.g., automatically or interactively by a
technician operating the respective computer equipment. From the
data of the virtual prosthesis, computer numerical control (CNC)
instructions are derived. These are CNC-instructions of two kinds.
Firstly, CNC-instruction are derived for fabricating the dental
prosthesis in a CAM (Computer-added Manufacturing) high-speed
milling/grinding machine (IIIII and JJJJJ). Moreover,
CNC-instructions (UUUUU) are derived for fabricating a splint in
step (VVVVV and WWWWW) that individually fits to the corresponding
prosthesis.
[0276] In a further embodiment of the aforementioned fabrication
process, the two steps SSSSS and TTTTT can be combined to one step.
Therefore, a three-dimensional camera can be used as known from the
CEREC three-dimensional camera systems provided by the Sirona Group
to avoid the process (SSSSS) taking a physical impression of the
dental anatomy of interest. As in the fabrication process depicted
in FIG. 58, a computed tomography device is used for imaging the
dental anatomy of the patient's tooth to be replaced and its
adjacent teeth.
[0277] From the surface data, the CNC-instructions can also be
derived for a chair side fabrication device. Such a chair side
fabrication device for dental prostheses is known from the inLab MC
XL milling unit which is offered by the Sirona Group. Therewith, in
an exemplary embodiment of the present invention, the prosthesis
and the corresponding splint can be fabricated at the dentist's
site. Firstly, this is a simplification of the overall fabrication
and delivery process. Especially, for dentists that have their own
milling unit for fabricating crowns etc., the chair side production
enhances the overall treatment process and saves time, e.g., in
cases where fast replicas are needed by a patient.
[0278] In a further enhancement of the present invention depicted
in FIG. 59, the attachable splint (24000) provides a number of
recesses (39000) formed as holes. Other methods of perforation may
be used. This enhancement of the attachable splint (24000) can be
useful for the adhesive material, e.g., glue, which attaches the
splint to the prosthesis (200) and the adjacent teeth (39020). An
adhesive that needs to attach to a smooth splint surface may not
provide enough stability since no hold points are provided for the
adhesive to attach to. The holes through the splint enhance the
adhesive in attaching to the splint. The adhesive material can
propagate into the holes or the perforations and, after having
changed into solid state, provide additional mounting means between
splint and prosthesis or adjacent teeth respectively.
[0279] Another embodiment of the present invention is depicted in
FIG. 60. Therein, the splint (43000) is designed in a way that it
is attached to the dental prosthesis (200) and to one of the
adjacent teeth (43010). Such a splint design can be useful in cases
where the other adjacent tooth (43020) on the opposite side of the
prosthesis (200) is not qualified for the attachment of a wing of
the splint (43000).
[0280] Another embodiment of the present invention is depicted in
FIG. 61. This embodiment is characterized by a splint (44000) which
is not only attached to the prosthesis (200) and the adjacent teeth
(44010) but also to the next teeth (44020) adjacent to the adjacent
teeth (44010) of the dental prosthesis (200). Such an embodiment of
the splint can be useful when the two directly adjacent teeth
(44010) are not qualified for providing primary stability to the
prosthesis (200) via the splint. The enhanced splint, therefore,
makes use of the stability of the next teeth (44020) adjacent to
the adjacent teeth (44010). Any combination of the foregoing is
possible to reflect limitations of the dental anatomy of interest,
attaching the prosthesis to one or more adjacent teeth, on one or
either side of the prosthesis.
[0281] In an exemplary embodiment of the present invention, a
dental prosthesis (50000) is proposed as depicted in FIG. 62. In
the shown embodiment, the crown portion body (50010) and the splint
(50020) form one part, i.e., the crown portion body entails wings
(50030) that attach to the adjacent teeth (50040).
[0282] A cut view (50100) of this prosthesis (50000) is depicted in
FIG. 63. In this cut view (50100) it can be seen, that the
prosthesis (50000) comprises a one-part implant (50110) and a cap
(50120) forming one part with its wings (50030) attaching to the
adjacent teeth (50040). The cap (50120) can be attached to the
one-part implant with adhesive means such as cement. However, a
partially adhesive silicone (50130) can also be used for attaching
the cap to the one-part implant. This provides the advantage that
micro-movements of the cap and splint (as one part) are damped.
This reduces the micro-movements of the implant and, thereby,
enhances the integration of the implant into the alveole.
[0283] A further enhancement of the present fabrication process is
shown in FIG. 64. Therein, two sets of surface-data are shown,
i.e., surface-data of the crown portion (53010) of the original
tooth derived from the impression of the patient's denture and
surface-data derived from the computed tomography image (53020)
providing information on the whole anatomy of the patient's
non-functional tooth. It is to be noted that the uncertainty of the
dataset provided by the impression lies at about 10 to 50
micrometer. The uncertainty of the dataset obtained from the
computed tomography device shows an uncertainty within 200 to 300
micrometer. The impression data may include digital representations
of the gum line surrounding the crown of interest.
[0284] Having these two types of surface-data, it is of interest to
combine both datasets in the overlapping region (53030), i.e., in
the area of the crown portion. For this combination of datasets,
the overlapping regions of the two datasets are placed together
using bets-fit algorithms. From the combination of the two
datasets, a goodness/performance value of the fit is obtained as a
value being calculated from the differences between the two
datasets at corresponding points of the virtual prosthesis surface.
Such a goodness value represents a measure representing the
quality/performance of the fitting of the two datasets. For
example, the sum of the distances raised to the second power could
be used to calculate such goodness value of the best fit. From the
combined dataset (53040), CNC-instructions are derived for the
fabrication of the prosthesis.
[0285] In the following, a procedure is described for enhancing the
quality of the combined dataset. The proposed method/procedure
executes the following steps: At first, the surface dataset derived
from the impression (virtual crown) and the surface dataset derived
from the computed tomography device data (virtual tooth with roots)
are combined to one surface dataset of a virtual tooth. For this
fitting combination a first goodness value is calculated that is
saved electronically for further steps. Then, the surface data of
the virtual tooth (combined dataset) is modified, e.g., blown up,
biased, moved with respect to inclination and position etc. In a
further step, the modified dataset of the virtual tooth is fitted
to and combined with the original dataset of the impression. From
this second combination of datasets, a second goodness value is
derived. This second goodness value is saved electronically and
compared to the aforementioned goodness value. If the new goodness
value is greater, than the first goodness value, the aforementioned
procedure is repeated. I.e., the second combined dataset is
modified as before, e.g., blown up, biased, etc.
[0286] This iterative procedure is repeated several times with
different, e.g., systematically or randomly chosen modifications
being applied to the respective combined dataset. In doing so, it
is a goal to find or identify a maximum goodness value. For this
search of the maximum goodness value, many kinds of statistical
methods and mathematical optimization methods can be utilized in
which the kind of modifications and the directions of modifications
are derived from adaptive algorithms based on the kind of
modification and its direction and the gradient of the quality
(i.e., the goodness value) calculation the goodness value
iteratively.
[0287] In a further embodiment as shown in FIG. 65, the prosthesis
(200) shows a special form which in comparison to the natural form
of the original tooth provides advantageous features in the process
of integration. The problem with a prosthesis providing the form of
the original tooth is that in the process of integrating the tooth
into the alveole it may happen that, e.g., an air inclusion
(46020), like a bubble, or bacteria (46030) may settle beneath the
upper area (46040) between the roots of the dental prosthesis. The
reason for this settlement of bacteria and/or air inclusions is
represented by the three-dimensional extension of a concave lower
limitation (46041) as shown for example, in the cut surface
(46042). It is shown in the cross-section view (X-X) of the
prosthesis (46043) where the air inclusion (46020) is located in
the upper area (46040) between the roots of the tooth. By modifying
the design of the dental prosthesis (200) with a convex lower
limitation (46050) of the shown cut surface, a prosthesis is
provided with a form that enables air inclusions (46060) to slide
up along the sides (46070) of the prosthesis. Thereby, the
settlement of bacteria in that area (46040) between the root
portion of the proposed dental prosthesis (200) can be avoided. The
design and modification process can be performed on a standard CAD
computer system using a standard software that is able to visualize
and manipulate surface data (e.g., in STL format). For example, the
software application product Studio 11 (Geomagic) is very much
suited to perform the aforementioned modification of the prosthesis
design. Also the aforementioned software products MAGICS and
SolidWorks are suitable for this task.
[0288] In another embodiment, the design modification of the
prosthesis would include displacing the forked shape between the
legs of the root portion in the direction of the root tip(s). This
would be a clinically indicated beneficial modification over the
actual corresponding shape of the non-functional tooth, to increase
the transgingival middle portion in order to have more vertical
height for the gingiva to seal gum and the prosthesis surface
against bacterial penetration.
[0289] A method for delivering a prosthesis to a customer according
to an embodiment of the present invention is depicted in FIG. 66.
This process enables the dental prosthesis (200) or components
thereof to be delivered in a wet environment (33000). This wet
environment can be achieved by a package filled with a fluid or
humid gas. It is exceptionally important that the outer surface of
the root portion body is moistened. Thereby, non-biocompatible
substances are prevented from occupying the outer surface of the
root portion body which could lead to disabling the ability of
cells to populate the root portion areas. Also, air bubbles that
sit in the porosity or cavities of the roughened surface could
disturb tissue integration. In the first step (KKKK), the finished
dental prosthesis (200) is placed in a liquid (33010). The liquid
(33010) is contained e.g., in an elastic bag or in a glass
container (33020). The liquid is favorably a biocompatible liquid
such as an isotonic solution of sodium chloride. In the further
process, ultraviolet electromagnetic radiation (33030) is applied
to the dental prosthesis (200) in a low pressure environment
(33040) such as a vacuum oven. This treatment of the surface of the
dental prosthesis, e.g., composed of zirconia, with ultraviolet
light enhances the bioactivity of the surface of the dental
prosthesis on osteoblasts. Att showed in Biomaterials 30 (2009)
1273-1280 that the treatment of zirconia with ultraviolet light
enhances its bioactivity on osteoblasts. Alternatively, a plasma
cleaning process can be used to create hydrophilic surface
conditions. In the second step (MMMM), the glass container (33020)
is closed with a cap (33050), thereby providing a firmly protected
dental prosthesis (200) for the delivery to further process steps.
In the next step (NNNN), the dental prosthesis (200) and its
environment (33060) in the glass container (33050) is sterilized by
applying a high pressure hot steam sterilization process. In this
high pressure hot steam sterilization process, the glass container
(33050) including the dental prosthesis (200) and the surrounding
liquid are placed in an oven with increased pressure. In this oven,
the temperature is increased (33065) up to a temperature regime in
which the dental prosthesis and the liquid are sterilized. To avoid
the breaking of the glass container during the increase of
temperature in the oven due to the increased pressure inside the
glass container with rising temperature, an increased pressure
(33070) is applied to the environment of the glass container. In
addition or alternatively, a membrane can be used to seal the
container, such membrane to allow gas and steam to penetrate, while
water in its liquid stage would not be able to penetrate the
membrane. In the next step (OOOO), the sterilized glass container
is packed into a padded packaging box (33080) for the save delivery
to the customer. In order to further optimize the wetting of the
surface intended to integrate with tissue, vacuum and/or ultrasonic
vibrations can be applied to release air bubbles from the surface
of interest.
[0290] In another embodiment of the present invention depicted in
FIG. 67, a pad (36000) is utilized to provide a selection of
different areas (36010) of varying color (36020) and texture
(36030). The pad (36000) can be utilized for an esthetic adjustment
being applied on the dental prosthesis to be fitted esthetically to
the adjacent teeth. In a first step, the tooth (36040) to be
replaced is placed aside the pad (36000). A skilled person, e.g.,
the dentist of record, compares certain spots and stains (36041)
present on the natural tooth to be replaced (36040) to the
different areas on the pad (36000), thereby identifying which
color-area or texture-area (36050) on the tooth corresponds to an
area (36010) on the pad. By taking a picture (36060) and printing
it, the dentist can mark on the picture (36060) which area (36050)
on the tooth corresponds to a certain area (36010) on the pad,
e.g., by drawing arrows (36070) on the picture (36050) between the
pad and tooth. In the process of esthetically adjusting the dental
prosthesis to the adjacent teeth, a skilled person can utilize the
color pad in comparison to the picture to make the adjustments,
e.g., by painting stains and marks on the dental prosthesis. This
step is of particular importance since the true colors of a tooth
(36040) are usually not well represented on a picture. By the
proposed method the dental prosthesis receives a natural look
fitting esthetically to the adjacent teeth and providing the
natural stains and marks that were already present on the tooth
that was replaced.
[0291] In an exemplary embodiment, a cross-sectional view of a
one-piece dental prosthesis is shown in FIG. 69. The term one-piece
refers to the root body (51010) portion and the crown body (51020)
which are assembled as a one piece body (51000). The body (51010)
is mainly composed of a ceramic material. This can be pure
zirconia, or a ceramic matrix composite like yttria-stabilized
(tetragonal phase) zirconia (e.g., Y-TZP zirconia, NaceraZ
Medium/Ivory, Doceram), alumina-toughened zirconia (e.g.,
ZIRALDENT.RTM., METOXIT) or zirconia toughened alumina. On the top
of the one piece body (51010), a translucent cap, the crown body
(51020) is made of feldspar ceramics or lithium disilicate ceramics
(e.g., IPS e.max CAD HT--highly translucent--or IPS e.max CAD
LT--low translucent, available in various color shades, Ivoclar
Vivadent) is placed and attached with adhesive means (51030). This
is for example, a temporary silicon based adhesive (e.g.,
TempoSIL.RTM.2, coltene whaledent), a temporary non-silicon based
adhesive (e.g., eugenol-free cement, e.g., RelyX.TM. Temp NE, 3M
ESPE), or a permanent cementation (e.g., RelyX Unicem, 3M ESPE).
The spacing between the one piece body (51010) and the translucent
glass cap (51020) can be adjustable depending on the adhesive
material used for the attachment of the glass cap onto the ceramic
body portion. In an exemplary embodiment, the gap is 100 microns.
An advantageous range is between 50 and 200 microns. In an
alternative embodiment, the adhesive material (51030) can be
composed of glass solder (e.g., Hotbond Tizio silicate coating and
Hotbond Plus, DCM), where the parts are fused together utilizing a
hot-bond process. In the process of integration, the one-piece
dental prosthesis (51000) can be placed into the alveole as a
whole. Note, this is in contrast to procedures used with state of
the art dental implants where a root portion is integrated and in a
further step a crown portion is attached to the root portion. In
order to prepare the surfaces of interest, a cold-processed
tribochemical method for silicatising surfaces may be applied
(e.g., Rocatec Plus by 3M ESPE). The silicatised surface is
prepared for bonding (e.g., cementing) by applying a silanising
surface conditioning, i.e., a silane resin primer (e.g., ESPE Sil,
3M ESPE).
[0292] In an exemplary embodiment, a hot processed glaze finish
(e.g., Crystall/Glaze and Crystall/Glaze Liquid, Ivoclar Vivadent)
is applied to the translucent crown cap (51020) prior to temporary
or permanent bonding.
[0293] Usually a crown is bonded in the patient's mouth in the
dentist's office. In an exemplary embodiment of the invention, the
bonding takes place at the site of the manufacturer to thereby
increase accuracy and the quality of the bonding itself
[0294] Koebel et al. disclose in WO 2008/017472 a rough, porous
osseoconductive topography of a zirconia implant surface that
promotes bonding between the implant and tissue, where in a
mixture, comprising of a polymer and at least one ceramic material
is applied on a substrate, the mixture further comprising inorganic
binders, e.g., phosphates, silicates, carbonates, sulfates.
However, it has not been recognized until now by the inventors that
dental implants, abutments, prostheses or parts thereof are
individualized in its three-dimensional shape prior to such surface
coating.
[0295] The shape design of mass-produced implants shows a
standardized joint between the implant and the crown portion. While
the crown is usually custom-shaped to the adjacent and opposite
teeth, the implant is not. Therefore, the joint between such
traditional crowns and implants is non-customized. Such joints are
usually shaped with standardized cylindrical, hexagonal, and
conical shape portions. E.g., the hexagonal rising (59030) shown in
FIG. 68 (prior art) that is described to serve as prosthesis
interface having a generic shape.
[0296] In order to obtain a positive lock between the implant and
the crown, numerous standard form joints are manufactured in order
to try to cover a majority of the possible crown designs. This,
however, results in significant additional manufacturing costs and
difficulties in inventory management. Alternatively, a smaller
number of "standard" designs are manufactured designed to cover
most cases. Although the smaller number helps reduce inventory
management problems and manufacturing costs, it has been found too
often lead to inadequate joint connections and in increased number
of collisions between components as the clinician is often provided
an improperly fitting connection. That is, the joint having a
smaller footprint than ideal is often employed in order to allow
for adjustments due to the inadequate connection. Recognized,
therefore, by the inventors is the need for a custom joint which
can provide a good positive lock between the implant and the
crown/intermediate abutment, and which can maximize the "footprint"
between the connecting pieces.
[0297] Massoud describes in US 2003/0118968 a "scallop-shaped
curvature of the juncture of the implant and subsequently attached
crown at the gum line" as an attempt to account for an anatomical
3D curvature, where the outer joint-line follows the gum line,
showing a curvature like a saddle shape.
[0298] FIG. 68 (prior art) illustrates a natural tooth having a
natural enamel crown (57020), a natural dentin root (57000) and the
natural juncture between dentin and enamel (57010) showing an
individual asymmetric outer contour line on the left hand side of
the figure. The implant indicated by (57030) in the middle and
right hand side of the figure is a prior art dental implant having
a cross-section (59040) showing a cylindrical or respectively
slightly conical screw portion having concentric convolutions or
threads and having an occlusually facing generic prosthetic
interface including a symmetric and generic hexagonal rising
(59030), and showing a symmetric and generic scallop-shaped surface
(59050) having a symmetric and generic shaped edge (57050) between
the surface (59050) and the concentric outer screw shape. Each of
these features are shown in top view on the upper right hand side
of the figure. The view shown in the middle of the figure shows a
prosthetic crown (57040), which is affixed to the aforementioned
hexagon rising (not shown in the middle view) of the prior art
implant (57030).
[0299] The inventors, however, recognize the limitations of such
anatomically shaped mass-produced implant joint portion where a
limited amount of standardized shape is supposed to fit all
individual situations of the patients of interest.
[0300] Accordingly, various embodiments of the present invention
provide apparatus and methods of manufacturing or otherwise
providing a custom prosthesis interface having a three-dimensional
surface shape positioned and formed to create a form locking fit
with respect to the crown/abutment and the implant body, which can
maximize or at least significantly increase the footprint of the
locking fit, which can reduce and/or eliminate collisions between
manufactured components, and which allows individualized
stocking--thus, eliminating the need to manufacture multiple
potential versions of the joint.
[0301] Again, FIG. 69 illustrates an exemplary embodiment of the
present invention. The prosthesis (51000) shown in the figure has
an anatomically custom-shaped edge to the cross-section (51050)
adjacent the gum line, where the root-shaped outer surface portion
corners to an occlusually-facing interface portion (51044) to
receive the crown cap (51020). The joint line of the juncture
(51030) between the implant body (51010) and the crown cap (51020)
shows in the cross-sectional view an individual, asymmetrical
custom-shaped rising over the circumferential edge (51050)
curvature in the direction of the main longitudinal axis of the
prosthesis. The occlusually-facing surface (51044) of the implant's
body (51010) correlates in its three-dimensional shape to the
corresponding interface surface (51042) of the crown (51020),
together creating a form-locking fit. Further, in an embodiment of
the prosthesis, the individual, custom-shaped curvature of the
outer joint (partially shown in the cross-sectional view as edge
51050) is designed and manufactured to follow either an adjacent
the gum line of the gingiva (51060) of the patient or parallel to a
bone crest shape, or a combination thereof.
[0302] The design process of both the implant body (51010) and the
crown cap (51020) includes deriving from clinical imaging data
representing the bone crest and/or the gum line, the virtual
representation (i.e., the custom design) of the adjacent joint
surface shapes (51042 and 51044) of the virtual representations of
the implant body and of the crown cap. In another method step,
numerical machine control data are derived from the custom design
of the joint shape and parts are machined (or made otherwise by
rapid prototyping technologies) based on such numerical machine
control data, the parts having physical joint shapes substantial to
virtual custom design data.
[0303] According to the illustrated embodiment, the customized
joint interface (51030) between the implant body (51010) and the
crown cap (51020) comprises a customized three-dimensional shape,
i.e., a three-dimensional surface that separates the crown portion
(51042) from the root portion (51044). In contrast to joints known
from the prior art between an abutment and a crown, the shown joint
is a customized joint which individually correlated to the dental
anatomy of the patient's tooth to be replaced and the adjacent
dental structures, including the gum lime, the bone socket, the
adjacent and opponent crowns. This means that the points of
separation along the juncture gum (51060) at the intersection
between the root portion and the crown portion are individually
designed, and individual, in most cases asymmetrical instead of
showing a generic symmetrical shape. Moreover, the course of the
joint is individually form-fitted to the form of the crown cap
(51020) to be placed on the implant body (51010).
[0304] A problem occurs when both, the implant body (51010) and the
cap (51020) are fabricated in a parallel process, i.e., both the
implant and crown are fabricated based on data obtained from the
scan and impression of the original denture. Then, the customized
joint interface (51030) is designed for both parts based on the
aforementioned data. However, in such a parallel fabrication
process, small fabrication failures and inaccuracies can lead to
two joint portions (i.e., two three-dimensional surfaces of the
implant body and the crown portion) that in some cases do not
totally fit together. This is especially an issue when the two
parts are both made of hipped (HIP) zirconia since only small
corrections can be applied to such a material. In an exemplary
fabrication method of the aforementioned prosthesis (51000)
depicted in FIG. 69, the implant body (51010) and the cap (51020)
are instead fabricated in a serial fabrication process. Therefore,
in a first step, the implant body (51010) is fabricated with a
customized surface forming the root portion and the joint portion
(51044). In a further step, the three-dimensional surface is
scanned or an impression is taken, thereby, acquiring data that
actually represents the embodiment of the customized joint as it is
embodied in the fabricated implant body (51010). The data obtained
from the scan of the customized joint (51030) is then utilized for
the fabrication of the cap (51020) having a customized joint
portion that fits to the joint portion of the implant body (51010)
with a high accuracy.
[0305] In stark contrast, the common process using CAD/CAM
technologies making dental crowns and bridges receives the custom
shape of the tooth preparation to form the joint between the
natural tooth (or even of a custom shaped abutment); however, such
joint shapes are not custom generated or designed (i.e.,
originated) in the virtual domain, they are physically man-made and
shaped by the doctor of record in the mouth of the patient of
interest. When in new state-of-the-art developments abutments (the
transgingival middle-pieces that connect the implant screw with the
crown) are custom shaped with respect to the outer shape that
finally receives the crown, the implant facing joint/interface
surface is of a three-dimensional standard (i.e., non-custom)
geometry.
[0306] FIG. 70 illustrates a cross-sectional view of another
exemplary embodiment of the present invention. The prosthesis
(51005) has an anatomically custom-shaped edge to the cross-section
(51055) adjacent the gum line of the gingiva (51065), where the
root-shaped outer surface portion corners to an occlusually-facing
interface portion (51048) to receive the crown cap (51025). The
joint line of the juncture between the implant body (51010) and the
crown cap (51020) shows in the cross-sectional view an individual,
asymmetrical custom-shaped indent over the circumferential edge
(51055) curvature in the direction of the main longitudinal axis of
the prosthesis. The occlusually-facing surface (510488) of the
implants body (51015) correlates in its three-dimensional shape to
the corresponding interface surface (51046) of the crown (51025),
together creating a form-locking fit. Further, in an embodiment of
the prosthesis, the individual, custom-shaped curvature of the
outer joint (partially shown in the cross-sectional view as edge
51055) is designed and manufactured to follow either adjacent the
gum line of the gingiva (51065) of the patient or parallel to a
bone crest shape, or any combination thereof.
[0307] FIG. 71 shows a cross-sectional view of a single tooth
prosthesis (57000) which is a variant of the embodiment of the
dental prosthesis shown and described in context of FIG. 69 and
shows a compound one-piece prosthesis with a first joint between an
implant body (57080) and a transgingival cap (57090) and a second
joint between the transgingival cap (57090) and a crown (57020).
The partially root-shaped implant body (57080) matches the
extraction socket (57085) of a pre-identified patient, without
interfering with or intruding into the surface socket itself. The
implant body (57080) is formed of, for example, commercially pure
titanium (e.g., medical grade 2 commercially pure titanium) or a
medical-grade titanium alloy (e.g., Ti.sub.6Al.sub.4V). The middle
piece, the transgingival cap (57090), is made, for example, of
ceramic material e.g., Y-TZP zirconia, and serves a similar purpose
of an abutment in traditional dental implantology. In an exemplary
embodiment, the transgingival cap (57090) is favorably tooth
colored, e.g., in its white body state, prior to final sintering by
volumetric coloring (e.g., color liquid e.g., Zirkon B4; C3; D4,
Zirkonzahn).
[0308] Further in the exemplary embodiment, the implant body
(57080) and the transgingival cap (57090) are fused together by the
above described hot-bond technology, where the titanium surface of
the interface (57110) is first silcatised by a coating applied in a
heating process (e.g., Hotbond Tizio silicate coating), then the
two parts of interest (57080 and 57090) are glass soldered (e.g.,
Hotbond Plus, DCM), building together a fused extended implant
body. The outer joint line (shown as an edge 57055) in the
cross-sectional view of the joint (57100) is sub-gingivally
positioned and the transgingival cap or abutment portion (57090) is
permanently fused and sealed reducing significantly the risk of an
opening or gaping under load and of bacteria colonization at the
interface compared to traditional implants. The interface between
the transgingival cap and the crown is discussed in the context of
FIG. 69.
[0309] The embodiment of FIG. 71 has two fully custom-shaped joints
or interfaces, the one (57100) positioned sub-ginivally positioned
e.g., at the bone crest level, and the second (57040) positioned
iso- or supra-gingivally. Each pair of surfaces that build the two
prosthetic interfaces (57110 and 57105) and (57040 and 57035)
create a form locking fit. The respective three-dimensional
surfaces (shown as cross-sectional view) dimensionally correlate
with the outer three-dimensional shape (57070) of the crown (57020)
and dimensionally correlate with each other. According to the
exemplary configuration, the design of the shapes of both joints is
created or originated in the virtual domain using the digital data
representing the anatomical specifics of interest. There is a
minimal thickness of 0.2 mm to be considered for the middle-piece
i.e., the transgingival cap (57090). In the exemplary
configuration, the outer joint line of the interface between the
implant body (57080) and the transgingival cap (57090) (shown in
the cross-sectional view as edges 57055) follows the saddle shaped
3D curvature of the bone crest adjacent the anatomical socket,
while the outer joint line of the interface between the
transgingival cap (57090) and the crown (57020) (shown in the
cross-sectional view as edges 57050) follows the saddle shaped 3D
curvature adjacent the gum line of the gingiva (57090).
[0310] Again, this is not a standard curvature of a cylindrical
mass-produced implant. To the very contrary, this design is
individually performed per specific tooth of a pre-identified
patient. The shape data are derived from clinical images of the
dental anatomy of such patent. In this specific context the design
takes into account, first the anatomical cross-section of the
implant body (57080) substantially matching the shape of the
extraction socket, or matching the root of the tooth being
extracted, and substantially perpendicular to that cross-section,
the 3D curvatures of the two joints between the three parts (e.g.,
made of different materials) in the longitudinal axis of the dental
tooth prosthesis. The substantially parallel gap between the two
adjacent surfaces that build the interface is about 100 microns to
accommodate a minimal thickness of the glass solder for the
sub-gingival joint and for the cement for the iso- or
supra-gingival joint.
[0311] In a further exemplary embodiment, the shape of the surfaces
of each joint extend the outer joint line to the occlusal (i.e., in
the direction of the tip of the crown (57020)) to accommodate for a
maximum stability for the assembly to withstand mastication
forces.
[0312] Note, applicable descriptions of FIG. 69 apply to the
descriptions of FIG. 71 and vice versa.
[0313] FIG. 72 shows an exploded view of a dental prosthesis having
a crown (56030), a trans-gingival portion (56020), an implant body
(56010), and a splint (56000). FIG. 72 further shows, for example,
the three-dimensional extensions of the surfaces shown in
cross-sectional view in FIG. 71. According to the illustrated
configuration, each transversal and lateral cross-section of the
components (56030, 56020, 56010 and 56000) are custom-shaped,
having an individual three-dimensional shape that is substantial
asymmetric, does not include generic concentric shapes, does not
include generic symmetric shapes, and does not include
convolutional shapes. The respective form-locking fit of the
prosthetic interfaces between surfaces (56055) and (56050) and
between surfaces (56040) and (56045) is clearly indicated for those
skilled in the art. The outer circumferential edge (56025) of the
surface (56045) varies in the direction of a mainly longitudinally
axis of the implant body (56010) and in transversal direction with
respect to the distance to such longitudinal axis. For those
skilled in the art, it is clearly indicated that the
three-dimensional shapes of the aforementioned interface surfaces
correlate with the outer surface of the crown (56030) and with each
other. The maximal transversal dimension of the implant body
(56010) adjacent the outer circumferential edge (56025) is
significantly bigger than the minimal transversal dimension of the
implant body (56010) adjacent the outer circumferential edge
(56025).
[0314] FIG. 73 shows a labial view of a dental implant prosthesis
(57000) having a crown portion (57060) and a root portion (57040)
being separated at a junction that shows in the view of the figure
as a circumferential line (57070). In the lateral view of FIG. 73,
the circumferential line (57070) is asymmetrical, having a
different slope or steepness in the direction of the proximal
height of that line on one side (57080) compared to the slope or
steepness in the direction of the proximal height of that line on
the other one side (57085).
[0315] FIG. 74 shows a cross-sectional lateral view of a dental
implant prosthesis having a crown portion (59010) and a root
portion (59020) being shown separated at a junction (59060). In the
cross-sectional view of FIG. 74, the correlating surface lines that
build the form locking fit of junction (59060) are asymmetric,
having a different slope or steepness on one side compared to the
slope or steepness of the other one side.
[0316] FIG. 75 shows a top view (58050) and a cross-sectional
transversal view (58020) of a dental implant body (58000). The
maximal transversal dimension of the implant body shown in the top
view is significantly bigger than the minimal transversal dimension
of the implant body shown in the top view. Its outer
circumferential contour is asymmetric as shown in top view. The
cross-sectional view (58020) indicates a transversal cross-section
of the male portion surface (58010), i.e., a positive rising, of
the prosthesis interface that creates a form-locking fit to an
occlusally facing prosthesis component (as shown for example, in
FIG. 76). The maximal transversal dimension of the implant body
shown in the cross-sectional view (58020) is significantly bigger
than the minimal transversal dimension of the implant body shown in
the cross-sectional view. Its outer circumferential contour is
asymmetric as shown in top view, and correlates in its shape and
orientation to the outer shape of the top view (58050).
[0317] FIG. 76 shows a proximal lateral view of a dental prosthesis
(60000) having a crown portion (60010) and a root-shaped implant
body (60020), being separated at a junction that shows up as a
circumferential line (60030) in the view of the figure. FIG. 76
also shows a cross-sectional lateral view (60050) of the dental
implant body (60020). In the cross-sectional view (60050) of the
implant body (60020), the surface line (60040) of the occlusally
facing surface is asymmetric, having a different slope or steepness
on one side compared to the slope or steepness of the other one
side. In the proximal lateral view of FIG. 76, the circumferential
line (60030) is also asymmetrical, having a different slope or
steepness in the direction of the labial height of the line at
(60045) compared to the slope or steepness in the direction of the
lingual height of the line at (60040).
[0318] FIGS. 77-82 illustrate an example of a method of designing
the "two-piece" dental implant 51000 (shown in FIG. 69) to replace
a non-functional natural tooth 70000 positioned in a jawbone of a
specific pre-identified patient, and FIGS. 83-89 illustrate an
example of a method of designing the "three-piece" dental implant
57000 (shown in FIG. 71). As shown in FIG. 77 the "two-piece" and
"three-piece" design methods can include the steps of receiving
data describing a three-dimensional X-ray image 70010 of at least
portions of the patient's dentition (x-ray image data), and
receiving data describing a surface scan of a dental anatomy and/or
a physical impression of the dental anatomy 70020, defining
impression image data made prior to removal of the non-functional
natural tooth from the jawbone of the specific patient. The steps
can also include forming one or more three-dimensional virtual
models 70030 of at least portions of the non-functional natural
tooth 70000, for example, by combining the x-ray image data of the
x-ray image 70010 (including the location of the bone crest
line/bone-facing gum line 70040) and impression image data of the
surface impression image 70020 (including the location of the outer
gum line 70050), and forming the three-dimensional virtual model or
models 70030 of the non-functional natural tooth 70000 to include a
modeled virtual root portion 70060 and a modeled virtual crown
portion 70070 modeled or otherwise designed based upon to the x-ray
image data of the x-ray image 70010 and the impression image data
of the surface impression image 70020.
[0319] FIGS. 78-82 further detail exemplary steps of designing the
two-piece dental implant based upon the three-dimensional virtual
model 70030 of at least portions of the non-functional natural
tooth 70000. The steps of designing the dental implant include the
steps of forming a virtual dental implant body 70080 (FIG. 82)
modeling a physical dental implant body having a virtual prosthesis
interface (at 70090, FIG. 81) modeling a physical prosthesis
interface of the physical dental implant body to receive an
occlusally-facing dental prosthesis component 70100. The step of
forming a virtual dental implant body 70080 can include forming the
virtual prosthesis interface (at 70090, FIG. 81) to have a
three-dimensionally contoured implant body surface shape at least
partially correlated to a surface shape of an occlusally-facing
surface of the modeled virtual crown portion 70070 and crown
surface of the nonfunctional tooth 70000.
[0320] As perhaps best shown in FIG. 78, according to an exemplary
two-piece dental implant body configuration, the step of forming a
virtual dental implant body 70080 can include separating a portion
of the three-dimensional virtual model (including the modeled
virtual root portion 70060 and modeled crown portion 70070) along a
virtual outer gum line representation 70050. Note, according to the
illustrated configuration, the separation/transformation procedure
performed on virtual model 70030 can include both digital cutting
and digital thickening of the components 70060, 70070 to the inside
while maintaining the dimensional integrity of the outer surface.
For the two-piece example, this results in the root portion 70060
having a non-infinitesimal thickness as shown, i.e., having a
thickness of a substantial dimension. The virtual root portion
70060 shown in FIG. 78 is represented in digital surface data
format (e.g., STL), is defined by an outer shell 70061, an inner
shell 70062, and an occlusally-facing connecting surface 70063. The
design process step of thickening, generally employed in both
two-peace and the three-these configurations, creates an inner
(smaller) second shell, and then generates the surface boundary
that shows the thickness.
[0321] As perhaps best shown in FIGS. 79 and 81, the step of
forming can also include copying at least portions of the modeled
virtual crown portion 70070 to form a base shape of the virtual
prosthesis interface, reducing dimensions of the at least portions
of the modeled virtual crown portion 70070 to define a virtual
prosthesis interface model at 70110, and as shown in FIG. 81,
combining the virtual prosthesis interface model 70110 having
reduced dimensions with the virtual root body portion model 70060
to form the virtual dental implant body 70080.
[0322] As shown in FIGS. 79-80, according to this configuration,
the steps can also include forming the virtual occlusally-facing
dental prosthesis component 70100 (FIG. 82) modeling an
occlusally-facing dental prosthesis component, such as, for
example, a virtual crown component 70100. According to such
configuration, the step of forming the virtual crown component
70100 includes forming a complementing virtual dental implant
body-receiving (interface) surface 70120 (FIG. 80) modeling a
physical complementing interface surface to receive
occlusally-facing portions of the dental implant body 70080 to
create a form locking fit therebetween. This can be accomplished by
copying at least portions of the modeled virtual crown portion
70070 to form a base shape of the complementing interface surface
70120 of the virtual crown portion 70100, reducing dimensions of
the at least portions of the modeled virtual crown portion 70070 to
form the complementing interface surface model shown at 70130 (FIG.
79), and combining the virtual crown portion model 70070 with the
complementing interface surface model 70130 as shown in FIG. 80 to
form the virtual crown portion 70100 shown in FIG. 82.
[0323] Note, as shown in FIG. 79, the dimensions of the
complementing interface surface model 70130 is reduced to be
smaller than the dimensions of the virtual crown portion 70070, and
the dimensions of virtual prosthesis interface model 70110 is
reduced to be smaller than the dimensions of the complementing
interface surface model 70130. These dimensional reductions in the
three-dimensional size of the pairs of surfaces that build an
interface and/or form the form-locking fit, are to account for
manufacturing tolerances and to account for a certain thickness of
the layer of adhesive, cement or glass solder, etc., generally in
the range of 50 to 300 micrometers, but preferably approximately
100 micrometers.
[0324] FIGS. 83-89 further detail exemplary steps of designing the
three-piece dental implant 57000 (FIGS. 71 & 89) based upon the
three-dimensional virtual model 70030 of at least portions of the
non-functional natural tooth 70000. According to an example of the
three-piece dental implant body configuration, as perhaps best
shown in FIG. 83, the step of forming a virtual dental implant body
70200 (FIG. 88) includes separating a portion of the
three-dimensional virtual model 70030 along the virtual bone-facing
gum line representation 70040 to form a modeled virtual root
portion 70210 and a first modeled virtual crown portion 70220 (used
to form the modeled transgingival cap portion), and copying a
portion of the modeled crown portion separated at the outer gum
line 70002 to form a second virtual crown portion model 70230
modeling the physical crown.
[0325] As perhaps best shown in FIG. 84, the step of forming the
virtual dental implant body 70200 further includes copying at least
portions of the modeled first virtual crown portion 70220 to form a
base shape of the prosthesis interface 70240 (FIG. 88) and reducing
dimensions of the at least portions of the modeled first virtual
crown portion 70220 to define a prosthesis interface model 70310.
As shown in FIG. 85, the step of forming also includes combining
the virtual prosthesis interface model 70310 with the virtual root
body portion model 70210 to form the virtual dental implant body
70200 (FIG. 88).
[0326] As shown in FIGS. 84, and 86-88, the steps can also include
forming a virtual occlusally-facing dental prosthesis component
modeling an occlusally-facing dental prosthesis component, such as,
for example, a virtual crown component 70320 (FIG. 88) and/or a
virtual transgingival cap component 70330 (FIG. 88). The virtual
crown component 70320 can be formed by employing the procedures
described with respect to forming the virtual crown component in
the two-piece configuration, to include copying at least portions
of the modeled virtual crown portion 70230 to form a base shape of
a complementing interface surface 70340 (FIG. 87) of the virtual
crown portion, reducing dimensions of the at least portions of the
modeled second virtual crown portion 70230 to form the
complementing interface surface model shown at 70350 (FIGS. 84 and
87), and as shown in FIG. 87, combining the virtual crown portion
model 70230 with the complementing interface surface model 70350 to
form the virtual crown portion 70320 (FIG. 88).
[0327] As shown in FIGS. 84 and 86, the transgingival cap can be
formed using a similar set of procedures. For example, the step of
forming the transgingival cap component 70330 (FIG. 88) can include
forming a complementing virtual dental implant body-receiving
(interface) surface 70410 (FIG. 86) modeling a complementing
interface surface to receive occlusally-facing portions of the
dental implant body. This can be accomplished by copying at least
portions of the first modeled virtual crown portion 70220 (modeling
the transgingival cap portion) cut along the bone-facing gum line
representation 70040 to form a base shape of the complementing
interface surface 70410 of the transgingival cap portion 70330 and
to form the occlusally-facing surface of the transgingival cap
portion 70330, reducing dimensions of the at least portions of the
first modeled virtual crown portion 70220 modeling the
transgingival cap portion shown at 70420, reducing dimensions of
the at least portions of the first modeled virtual crown portion
70220 modeling the complementing interface surface 70410 shown at
70430, and as shown in FIG. 86, combining the virtual transgingival
cap model 70420 with the complementing interface surface model
70430 to form the virtual transgingival cap 70330 (FIG. 88).
[0328] Note, the dimensions of the complementing interface surface
model 70230 is reduced to be smaller than the dimensions of the
virtual crown portion 70070, the dimensions of the transgingival
cap portion model 70420 is reduced to be smaller than the
dimensions of complementing interface surface model 70430, and the
dimensions of virtual prosthesis interface model 70310 is reduced
to be smaller than the dimensions of the complementing interface
surface model 70430. These dimensional reductions in the
three-dimensional size of the pairs of surfaces that build an
interface and/or form the form-locking fit are to account for
manufacturing tolerances and to account for a certain thickness of
the layer of adhesive, cement or glass solder, etc., generally in
the range of 50 to 300 micrometers, but preferably approximately
100 micrometers.
[0329] One of ordinary skill in the art will recognize that various
aspects of the invention as explained above can readily be combined
with each other.
[0330] The meaning of "CAD" shall include but shall not be limited
to any and all technology of computer aided design.
[0331] The meaning of "CAM" shall include but shall not be limited
to any and all technology of computer aided manufacturing.
[0332] The meaning of "CNC" shall include but shall not be limited
to any and all technology of computer numerical control as it
relates to manufacturing machinery and systems, including but not
limited to rapid prototyping devices and systems.
[0333] The meaning of "rapid prototyping" shall include but shall
not be limited to all technologies qualified for manufacturing of
copies of virtual three-dimensional objects and also technologies
qualified for mass customization or the mass production of copies
of customized or adapted geometries to the needs of an individual
patient. Rapid prototyping in this context shall include but not be
limited to manufacturing technologies based on the digital data, by
a process that includes depositing material, in accordance with the
digital data, layer-by-layer in a plurality of layers each
constituting a two-dimensional cross section of a solid object
having an edge defined by data of the three-dimensional surface,
the layers being stacked in a third dimension to form the solid
object having a three-dimensional surface defined by the data. All
such rapid prototyping technologies can be used directly to
manufacture the part of interest, for example, by selective laser
sintering or indirectly by fabricating first, e.g., a resin or wax
sample of the part of interest and second using for example,
"lost-wax" casing to duplicate such sample and fabricate therewith
the part of interest. It also includes sintering techniques where
the "green" body is printed in response to computerized numerical
controlled (CNC) data and then sintered to its final material
properties. Sintering in this context includes pressure and
heat.
[0334] The meaning of "rapid prototyping" shall be used in its
broadest technical sense, where individualized parts are made from
virtual representations, and shall include respective additive,
subtractive and forming technologies used to three-dimensionally
shape work pieces. The meaning of "additive shaping" shall include
but shall not be limited to selective laser melting, selective
laser sintering, stereo-lithography, 3-D printing or depositing of
wax, wax-bound powders, adhesive-bound powders, slurries. The
meaning of "subtractive shaping" shall include but shall not be
limited to 3D laser shaping, CNC-grinding, CNC-turning, and
CNC-milling technologies, and other machining and finishing
technologies. The meaning of "shape forming" shall include but
shall not be limited to near net-shape forming technologies,
CNC-stamping, and CNC-pressing and casting technologies.
[0335] The meaning of "body" of an artificial tooth shall include
but shall not be limited to the part of the prosthesis representing
a root structure for periodontal or osseointegration or the
combined part of the prosthesis representing a root structure for
periodontal or osseointegration and a support structure for a crown
or a bridge.
[0336] The meaning of "prosthesis" shall include any substantially
artificially shaped part of any natural and artificial material. In
this sense a dental prosthesis for periodontal integration would
have to be distinguished to any human tooth used for intentional
re-implantation.
[0337] Whenever the context requires, the word "prosthesis" shall
be deemed to include the word "implant" and vice versa.
[0338] "3D" shall mean three-dimensional.
[0339] The meaning of "CT" shall include but shall not be limited
to any and all technology of computed tomography.
[0340] "CBCT" shall mean cone beam computed tomography and shall
include "DVT" technology.
[0341] "DVT" shall mean digital volume tomography.
[0342] "Three-dimensional X-ray image" shall include but shall not
be limited to voxel data, volumetric X-ray data, at least two
two-dimensional X-ray images in DICOM format, a stack of
two-dimensional X-ray images, data received from CBCT or other CT,
MRT, ultrasonic and TOF devices, or any combination thereof.
[0343] The meaning of "MRT" shall include but shall not be limited
to any and all technology of magnetic resonance tomography.
[0344] The meaning of "TOF" shall include but shall not be limited
to any and all technology employing Time-of-Flight procedures.
[0345] The meaning of "imaging" and "scanning" shall include but
shall not be limited to any and all technology of acquiring
two-dimensional and/or three-dimensional data of physical objects
or parts of a human body.
[0346] The meaning of clinical "imaging data" shall include but
shall not be limited to in-vivo and in-vitro processes that result
in any anatomical data of the anatomy of a human being. In this
context the term data shall include but shall not be limited to
two-dimensional and three-dimensional data.
[0347] The meaning of three-dimensional data shall include but
shall not be limited to surface (e.g., triangulated data) and
volumetric (e.g., voxel) data.
[0348] The meaning of "periodontal tissue" shall include but shall
not be limited to any soft tissue surrounding a tooth.
[0349] The meaning of "periodontal ligature", "ligament" or
"periodontal ligament" shall include but shall not be limited to
the fibrous connective tissue (e.g., human gingival fibroblasts)
interface usually located between a human tooth and the anatomical
structure of the jaw of a human being.
[0350] The meaning of each one of the following: "periodontal
integration", "parodontal integration", "integration into the
periodont", "integration into the parodont", "integration into the
dental soft-tissue", "integration into the dental ligament" and
alike word constructions shall include but shall not be limited to
the integration into the periodontal ligament structure or
perio-type tissue or any other biological structure of the human
dental anatomy except osseointegration. In this sense the term
periodontal integration shall include but shall not be limited to
the integration of a prosthesis to be adopted and held by
periodontal ligament tissue of a human being.
[0351] In this sense a prostheses for periodontal integration would
have to be distinguished to any osseointegrated implant.
[0352] The meaning of "cavity" shall include but shall not be
limited to the periodontal cavity, a cavity of the jaw bone
structure, a cavity of the alveolus or a combination thereof.
[0353] The meaning of "extraction socket" shall include prepared or
unprepared extraction sockets. The meaning of "prepared" shall
include but shall not be limited to being surgically pared,
abraded, scraped or curetted by mechanical instruments or laser
technology based devices.
[0354] The meaning of "replacement", "to replace", "to be replaced"
shall include but shall not be limited to any substitution, where
one object fills the former position of another object. In the
context of the foregoing such substitution can be performed at any
time, so that for example, the term replacement shall not be
limited to a replacement in a timely manner.
[0355] The meaning of a "manufactured one-piece" object shall not
be limited to homogeneous objects, and shall include but shall not
be limited to manufactured assemblies, objects that are coated,
objects that are consisting of more than one pieces or materials
bonded together or any combination thereof.
[0356] The meaning of a "clinical one-step" process or a "clinical
one-step" method shall include but shall not be limited to a series
clinical process or method steps performed in one or more clinical
events as long as no further iteration is required that includes
clinical process or method steps and process or method steps that
cannot be performed chair-side.
[0357] The meaning of "immediate load" of an implant shall include
but shall not be limited to any all integration concepts of
implants where the occlusal portion of the implant (e.g., the crown
portion facing the opponent jaw) is not protected against the
alternate load of mastication by additional protective means.
[0358] The meaning of "configured to be integrated into the
existing occlusion of the patients dentition" shall include but
shall not be limited to any shaping of a crown or a crown-like
portion of a prosthesis that contacts or otherwise substantially
fills the gap between adjacent crowns, and any shaping that
contacts or otherwise substantially interacts with the opponent
crowns of the dentition in the process of masticating food.
[0359] In dentistry, the term occlusion is used to refer to the
manner in which the teeth from upper and lower arches come together
when the mouth is closed. The meaning of "occlusion" shall mean but
shall not be limited to the manner the teeth of the upper or lower
arch are fitting and coming in contact with each other while the
mouth is closed or during chewing (articulation). It shall also
include the fit and contact of adjacent teeth within one arch. The
meaning of "integrated into the occlusion" shall include but shall
not be limited to the configuration and integration of the fit and
contact situation of a prosthesis within the existing or new build
occlusion within the same and the opponent arch.
[0360] The words used in this specification to describe the
invention and its various embodiments are to be understood not only
in the sense of their commonly defined meanings, but to include by
special definition in this specification structure, material or
acts beyond the scope of the commonly defined meanings. Thus, if an
element can be understood in the context of this specification as
including more than one meaning, then its use in a claim must be
understood as being generic to all possible meanings supported by
the specification and by the word itself.
[0361] The various embodiments and aspects of embodiments of the
invention disclosed herein are to be understood not only in the
order and context specifically described in this specification, but
to include any order and any combination thereof. Whenever the
context requires, all words used in the singular number shall be
deemed to include the plural and vice versa. Words which import one
gender shall be applied to any gender wherever appropriate.
Whenever the context requires, all options that are listed with the
word "and" shall be deemed to include the world "or" and vice
versa, and any combination thereof. The titles of the sections of
this specification and the sectioning of the text in separated
paragraphs are for convenience of reference only and are not to be
considered in construing this specification.
[0362] Insubstantial changes from the claimed subject matter as
viewed by a person with ordinary skill in the art, now known or
later devised, are expressly contemplated as being equivalent
within the scope of the claims. Therefore, obvious substitutions
now or later known to one with ordinary skill in the art are
defined to be within the scope of the defined elements.
[0363] In the drawings and specification, there have been disclosed
embodiments of the invention, and although specific terms are
employed, the terms are used in a descriptive sense only and not
for purposes of limitation, the scope of the invention being set
forth in the following claims. It must be understood that the
illustrated embodiment has been set forth only for the purposes of
example and that it should not be taken as limiting the invention.
It will be apparent to those skilled in the art that alterations,
other embodiments, improvements, details and uses can be made
consistent with the letter and spirit of the disclosure herein and
within the scope of this disclosure patent, which is limited only
by the following claims, construed in accordance with the patent
law, including the doctrine of equivalents.
[0364] This patent application is a non-provisional continuation
application and claims priority to and the benefit of now-pending
U.S. patent application Ser. No. 13/247,843, filed on Sep. 28,
2011, which itself claims priority to and the benefit of U.S.
Patent Application No. 61/454,450 filed on Mar. 18, 2011, and which
is a continuation-in-part of and claims priority to and the benefit
of U.S. patent application Ser. No. 12/763,001, filed Apr. 19,
2010, now U.S. Pat. No. 8,602,780, and is a continuation-in-part of
and claims priority to and the benefit of U.S. patent application
Ser. No. 11/724,261, filed Mar. 15, 2007, now U.S. Pat. No.
7,708,557, and is a continuation-in-part of U.S. patent application
Ser. No. 11/549,782 filed on Oct. 16, 2006, now U.S. Pat. No.
8,454,362, each incorporated by reference in its entirety.
[0365] In the drawings and specification, there have been disclosed
a typical preferred embodiment of the invention, and although
specific terms are employed, the terms are used in a descriptive
sense only and not for purposes of limitation. The invention has
been described in considerable detail with specific reference to
these illustrated embodiments. It will be apparent, however, that
various modifications and changes can be made within the spirit and
scope of the invention as described in the foregoing specification.
In the claims which follow, reference characters if used to
designate claim steps are provided for convenience of description
only, and are not intended to imply any particular order for
performing the steps.
* * * * *