U.S. patent application number 09/854717 was filed with the patent office on 2001-09-13 for customized dental abutments and methods of preparing or selecting the same.
Invention is credited to Osorio, Julian, Ziegler, Andrew.
Application Number | 20010021498 09/854717 |
Document ID | / |
Family ID | 26729995 |
Filed Date | 2001-09-13 |
United States Patent
Application |
20010021498 |
Kind Code |
A1 |
Osorio, Julian ; et
al. |
September 13, 2001 |
Customized dental abutments and methods of preparing or selecting
the same
Abstract
A customized dental abutment is provided which replicates a
tooth being replaced. The dimensions of the abutment are determined
by a computer algorithm that modifies standard tooth type models
according to a series of measurements taken of the site of desired
tooth replacement. Methods of the invention relate to taking a
series of measurements of the site of desired tooth replacement,
determining the type of tooth being replaced, and preparing or
selecting a customized dental abutment based on the measurements
and determination. The preparation or selection is made by
modifying standard measurements for the type of tooth being
replaced in conformity with the measurements taken of the site of
desired tooth replacement.
Inventors: |
Osorio, Julian; (Waban,
MA) ; Ziegler, Andrew; (Arlington, MA) |
Correspondence
Address: |
TESTA, HURWITZ & THIBEAULT, LLP
HIGH STREET TOWER
125 HIGH STREET
BOSTON
MA
02110
US
|
Family ID: |
26729995 |
Appl. No.: |
09/854717 |
Filed: |
May 14, 2001 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
09854717 |
May 14, 2001 |
|
|
|
09416011 |
Oct 8, 1999 |
|
|
|
6231342 |
|
|
|
|
09416011 |
Oct 8, 1999 |
|
|
|
08960046 |
Oct 29, 1997 |
|
|
|
5989029 |
|
|
|
|
60051957 |
Jul 8, 1997 |
|
|
|
Current U.S.
Class: |
433/173 ;
433/223 |
Current CPC
Class: |
A61C 8/0077 20130101;
A61C 8/006 20130101; A61C 8/005 20130101; G16H 20/40 20180101; A61C
13/0004 20130101 |
Class at
Publication: |
433/173 ;
433/223 |
International
Class: |
A61C 008/00; A61C
005/10 |
Claims
What is claimed is:
1. A customized dental abutment, comprising dimensions that
replicate those of a patient's natural dentition, wherein said
dimensions are determined by a computer algorithm that modifies
pre-programmed standard tooth shapes to generate a model of said
customized dental abutment.
2. The dental abutment of claim 1, wherein said dimensions comprise
a mesial-distal angle, a facial-lingual angle, a rotational axis of
a dental implant fixture implanted at a site of desired tooth
replacement, a width, a facial-lingual offset, a mesial-distal
offset, and a height from the gumline to the top of a dental
implant fixture implanted in a patient's mouth for the specific
tooth being replaced, as well as the type of tooth being
replaced.
3. The dental abutment of claim 2, wherein said dimensions further
comprise a height to the occlusal plane and a gingival profile of
said tooth being replaced, and said dimensions, including size,
position, orientation and inclination, of said adjacent and
opposing teeth of said tooth being replaced.
4. A method of preparing a customized dental abutment from a study
cast and impression of a patient's mouth, comprising the steps of:
(a) implanting a dental implant fixture in said study cast at the
site of tooth replacement as determined by said impression; (b)
measuring a mesial-distal angle of said site; (c) measuring a
facial-lingual angle of said site; (d) measuring an axis of
rotation of said fixture; (e) measuring a width of said site; (f)
measuring a facial-lingual offset of said site; (g) measuring a
mesial-distal offset of said site: (h) measuring a height from the
gumline to the top of said dental implant fixture; (i) determining
the type of tooth being replaced; and (j) preparing said abutment
based on said measurements and said determination.
5. The method of claim 4, further comprising the steps of: (a)
measuring a height to the occlusal plane of said site; (b)
determining a gingival profile of said site; (c) determining
dimensions of adjacent teeth; and (d) determining dimensions of
opposing tooth prior to said preparation step.
6. The method of claim 4, further comprising the steps of: (a)
entering said measurements into a computer programmed to generate a
model of said abutment based on said measurements; (b) generating
said model; and (c) creating a prototype of said abutment based on
said model.
7. The method of claim 6, wherein said computer is pre-programmed
to include a series of average shapes for the type of tooth being
replaced.
8. The method of claim 7, wherein said generating step comprises
the steps of: (a) comparing said average shape to said entered
measurements; (b) modifying said average shape in conformity with
said entered measurements; and (c) developing said model based on
said modified shape.
9. The method of claim 6, wherein said creating step comprises the
steps of: (a) building said abutment from said prototype; (b)
polishing said abutment; and (c) sterilizing said abutment.
10. A method of selecting a dental abutment from an inventory of
dental abutments, comprising the steps of: (a) determining a series
of measurements for a tooth being replaced; (b) determining a type
of tooth being replaced; and (c) selecting an abutment based on
said determinations.
11. The method of claim 10, wherein said measurements comprise a
mesial-distal angle, a facial-lingual angle, a rotational axis of a
dental implant fixture implanted at a site of desired tooth
replacement, a width, a facial-lingual offset, a mesial-distal
offset, and a height from the gumline to the top of a dental
implant fixture implanted in a patient's mouth for the specific
tooth being replaced.
12. The method of claim 11, wherein said measurements further
comprise a height to the occlusal plane and a gingival profile of
the tooth being replaced, and the dimensions, including the size,
position, orientation and inclination, of adjacent and opposing
teeth of the tooth being replaced.
13. The method of claim 10, wherein said inventory is a computer
inventory.
Description
FIELD OF THE INVENTION
[0001] The invention relates to customized dental abutments and
methods of preparing or selecting such abutments. More
specifically, the invention relates to customized dental abutments
fabricated through the use of a computer algorithm into which a
series of measurements taken of the site for tooth replacement are
entered.
BACKGROUND OF THE INVENTION
[0002] Dental restorative systems seek to provide cosmetic and
functional replacements for missing teeth. A dental restorative
system that replaces a single tooth typically includes three
components. These are the dental implant fixture, the abutment, and
the crown. The dental implant fixture anchors the restorative
system to the jawbone. The crown replicates the contour and
appearance of the visible portion of the restorative system to
match that of the natural dentition. Finally, the abutment connects
the crown to the dental implant fixture. The abutment also holds
the crown in proper alignment relative to the implant fixture, and
absorbs the stress of chewing. A customized abutment should also
match the size, shape and contour of the original tooth in order to
provide the best possible appearance.
[0003] Standard methods for preparing dental restorative systems
require considerable time, labor, and expense. Methods typically
require that the patient make between six and ten visits to the
dentist's office to complete installation of the restorative
system. An oral surgeon or periodontist is required to surgically
implant the dental implant fixture into the patient's jawbone. A
general dentist or prosthodontist typically performs the
measurement and fitting of the abutment and crown, and a technician
typically sculpts the abutment and crown.
[0004] During the first office visit, an impression of the
patient's existing teeth is made. During the second visit, the
dental implant fixture is installed in the patient's jawbone. At
the third visit, a temporary healing abutment is installed in the
implant fixture. After healing, a fourth visit is necessary to make
an impression of the patient's mouth showing the position of the
implant fixture relative to the natural dentition. From this
impression, a customized abutment is fabricated. At a fifth visit,
the abutment is installed along with a temporary crown. At the
sixth visit, the progress of gum healing is examined and a final
impression of the patient's mouth is made in order to determine if
the abutment needs to be further modified. At the seventh visit,
the crown is installed. The number of office visits required
increases if the abutment or crown needs to be modified before
installation of the final crown.
[0005] The standard procedure therefore requires a considerable
number of visits to the dentist's office for the patient and the
labor of up to three different dental professionals. This time and
labor adds to the high cost of undergoing a tooth replacement by
this method. Accordingly, there remains a need in the art for a
methods and materials that will aid in reducing the time, labor and
cost of dental implant restorations. The present invention
addresses this need by presenting customized dental abutments and
methods of preparing or selecting such abutments in a manner which
is quicker and less costly than standard techniques.
SUMMARY OF THE INVENTION
[0006] Dental abutments of the present invention are customized to
replicate a tooth being replaced. A series of measurements of the
tooth site is taken, including measurements of the mesial-distal
angle, the facial-lingual angle, the rotational axis of a dental
implant fixture implanted at the site of desired tooth replacement,
the width, the facial-lingual offset, the mesial-distal offset, and
the height from the gumline to the top of a dental implant fixture.
In addition to these measurements, a determination of the tooth
type (e.g., lateral incisor, first bicuspid, etc.) is made.
Additional measurements may include the height to the occlusal
plane and the gingival profile of the tooth being replaced. The
dimensions, including the size, position, orientation and
inclination, of the adjacent and opposing teeth may also be
made.
[0007] According to the invention, an abutment is customized by
entering measurements into an algorithm that modifies a standard
tooth shape for the type of tooth being replaced. The result is a
customized abutment that regulates characteristics of the tooth
being replaced.
[0008] Methods of the present invention provide for the preparation
of a customized dental abutment in a manner that reduces the amount
of time, labor and cost involved in dental restorative system
installation. It has now been realized that taking a series of
measurements of the site of tooth replacement allows for the
quicker and easier development of a customized dental abutment.
Accordingly, methods of the present invention allow for the design
and construction of a customized dental abutment based on such
measurements.
[0009] A method of the invention comprises implanting a dental
fixture into a study cast that was previously made of the patient's
mouth. This study cast works as a model of the patient's mouth and
shows the site of desired tooth replacement as well as its relation
to the surrounding teeth. The dental fixture is preferably placed
in the study cast using an impression coping device as described in
co-owned, co-pending U.S. Ser. No. 08/851,836, incorporated by
reference herein.
[0010] Once the dental implant fixture is placed in the correct
position in the study cast, a preferred method of the invention
provides for taking a series of measurements. The measurements
include the mesial-distal angle of the site of tooth replacement,
the facial-lingual angle of the site, the rotational axis of the
fixture, the width of the site, the facial-lingual offset of the
site, the mesial-distal offset of the site and the height from the
gumline to the top of a dental implant fixture implanted in a
patient's mouth. The specific tooth being replaced (e.g., lateral
incisor, first bicuspid, etc.) is also determined from its position
in the mouth. Based on these measurements a customized dental
abutment is fabricated. Other measurements may be used to guide the
manufacture of a customized dental abutment. These measurements
include the height of the occlusal plane, the gingival profile, and
the dimensions (e.g., height, width, etc.) of the adjacent and
opposing teeth.
[0011] In a particularly preferred method of the invention, a
computer program is used to generate a model of the customized
abutment based on these measurements. The computer is programmed to
generate a model of the customized abutment based on the particular
tooth being replaced and on the measurements and tooth and fixture
positions. The computer is pre-programmed to contain a series of
standard tooth shapes for each type of tooth. The standard shape
for the particular type of tooth being replaced is then modified to
conform to the measurements taken. From this customized model, the
computer program generates a file from which a wax prototype of the
abutment is generated. From the wax prototype, the abutment is
built. The technician need only polish and sterilize the abutment
before it can be permanently implanted in the patient's jaw.
[0012] Another method of the invention relates to selection of a
customized dental abutment from an inventory of such abutments. The
inventory is preferably a computer inventory. Measurements such as
the mesial-distal angle, the facial-lingual angle, the rotational
axis of the dental implant fixture, the width, the facial-lingual
offset, the mesial-distal offset, and the height from the gumline
to the top of a dental implant fixture implanted in a patient's
mouth are taken and compared to the inventory to select a model
that most closely replicates the actual tooth being replaced. In
addition to these measurements, a determination of the type of
tooth (e.g., lateral incisor, first bicuspid, etc.) being replaced
is made. Additional measurements may include the height to the
occlusal plane and the gingival profile of the tooth being
replaced, and the dimensions, including the size, position,
orientation and inclination, of the adjacent and opposing teeth of
the tooth being replaced.
[0013] Methods and materials of the present invention reduce the
number of visits that a patient must make to the dentist office, as
well as the time and labor required to complete a dental
restoration. The present invention allows for the patient to make
as few as three visits to a dentist's office. The first visit would
entail making the study cast for use in fabricating the abutment.
At the second visit, the dental implant fixture is installed and an
impression of the position of the dental implant fixture and its
relation to the natural dentition is made. The study cast and
impression are then used to fabricate a customized dental abutment,
as described above. No further modifications to the abutment are
necessary using the above process, so the abutment and crown can be
installed at the third and final visit to the dentist's office. The
abutment is fabricated to eliminate the need for a healing
abutment, as described in co-owned, co-pending U.S. Ser. No.
08/372,323, incorporated by reference herein.
[0014] The invention will be understood further upon consideration
of the following drawings, description and claims.
DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows a complete dental restorative system including
dental implant fixture 10, customized abutment 12, and crown
14.
[0016] FIG. 2A shows the various faces of an abutment of the
invention installed in a dental implant fixture.
[0017] FIG. 2B shows a facial view of the abutment of FIG. 1A.
[0018] FIG. 2C shows a side (mesial or distal) view of the abutment
of FIG. 1A.
[0019] FIG. 3 shows an impression coping device for use in
fabricating customized dental abutments of the invention.
[0020] FIG. 4A illustrates some of the various measurements taken
in order to fabricate a customized dental abutment of the
invention.
[0021] FIG. 4B illustrates some of the various measurements taken
in order to fabricate a customized dental abutment of the
invention.
[0022] FIGS. 5A-5H illustrate the various stages undergone in
designing a computer model of a standard tooth shape for use in
building a customized dental abutment of the invention.
[0023] Like reference characters in the respective drawn figures
indicate corresponding parts.
DETAILED DESCRIPTION OF THE INVENTION
[0024] The present invention relates to methods and materials for
use in dental restorative systems. A dental restorative system
replaces a tooth in a patient's mouth. A dental restorative system
is shown in FIG. 1 and comprises a dental implant fixture 10, which
is implanted in the mouth of a patient at the site of desired tooth
replacement. The dental implant fixture anchors the other
components of the system in proper position and alignment with
respect to the natural dentition. The system also includes an
abutment 12, which is installed in the dental implant fixture and
over which the crown 14 is affixed. The crown is the visible
portion of the restorative system, so it must be contoured and
shaped to look like a natural tooth. The underlying abutment should
also be fabricated to match the size, shape and contour of the
replaced tooth.
[0025] More specifically, present invention provides customized
dental abutments for use in dental restorative systems and methods
of preparing or selecting such abutments. An abutment of the
invention is fabricated based on the application of a series of
measurements taken at the site of tooth replacement to a standard
shape for the type of tooth being replaced.
[0026] A preferred abutment of the invention is shown in FIG. 2A. A
series of measurements is taken with respect to the different faces
of the abutment 12. FIG. 2A shows the mesial agent 16 and the
distal agent 18 of a typical abutment. The mesial agent is the side
facing the focial midline and the distal capect is the side facing
away from the facial midline. A side view of an abutment is also
shown in FIG. 2C, and this figure represents either a distal or a
mesial face.
[0027] FIG. 2A also shows the facial agent 20 and lingual agent 22
of an abutment. The facial agent of the abutment faces toward the
cheeks or lips, and the lingual agent of the abutment faces toward
the tongue. A view of the facial agent of an abutment is also shown
in FIG. 2B. Finally, FIG. 2A also shows an occlusal plane 24. The
occlusal plane is the surface of the tooth that comes in contact
with the surfaces of opposing teeth.
[0028] In methods of the invention, the foregoing measurements are
made with respect to their orientation to an implanted dental
fixture. Such measurements are used to fabricate a customized
dental abutment of the invention. Prior to the taking of such
measurements, however, some preparative actions should be taken by
the dentist, prosthodontist and/or oral surgeon. For example, a
study cast of the patient's existing teeth is made. Then, a dental
fixture, such as that manufactured by Life Core, is implanted in a
bore hole made in a patient's jaw at the site of desired tooth
replacement. The implant site is surgically prepared by drilling
into the jawbone after the gingival tissue surrounding the point of
insertion of the implant has been retracted. An implant fixture may
comprise a male hexagonal interface at its exposed end, as well as
a hollow bore, which is open from the exposed end of the fixture
and extends into the fixture.
[0029] An impression of the positional and rotational alignment of
the dental fixture with respect to the natural dentition must then
be taken. The impression ensures that the abutment and crown will
have the proper alignment to fit into the natural dentition. An
impression is preferably made through the use of an impression
coping device as shown in FIG. 3, and as described in co-owned,
co-pending U.S. Ser. No. 08/851,836, incorporated by reference
herein. Such an impression coping device comprises a head 17 having
a first end 19 that is preferably castellated so that it releasably
attaches to a dental implant fixture. The castellated end comprises
a plurality of axially extending, radially resilient fingers 21
that deflect as they are friction fitted over a mating surface,
such as the male hexagonal interface described above, of a dental
implant fixture. The coping device also has a guide stem 23, which
fits into the hollow bore of the dental implant fixture.
[0030] A coping device as described above is fitted into the dental
implant fixture and an impression material, such as, for example,
polyether siloxane or polyvinyl siloxane, is poured over the coping
device and surrounding teeth. Upon curing, an impression of the
natural dentition and their positional and rotational alignment
with respect to the dental implant fixture is preserved. A second
end of the coping device also contains one or more radially
arranged flanges 25 to anchor the impression molding material to
the coping device and facilitate its removal from the mouth upon
curing. The skilled artisan is aware that other coping devices for
making impressions are available and may be used to make an
impression as described above.
[0031] After the study cast and impression are completed, methods
of the invention provide for the fabrication of a customized dental
abutment from the study cast and impression. A dental implant
fixture is first implanted in the study cast at the site of desired
tooth replacement. The impression is used to guide the proper
rotational and positional alignment of the dental implant fixture
in the study cast. The impression coping device containing the
attached impression material is attached to an analog fixture,
which is then cast in the study cast. The space surrounding the
analog fixture is then filled and allowed to cure so that the
analog fixture becomes part of the study cast, thus maintaining the
proper positional and rotational alignment of the dental fixture
with respect to the patient's natural dentition.
[0032] After the analog fixture is properly placed in the study
cast, measurements may be made. Measurements may be taken by
several means including, but not limited to, a stent, a mold of the
teeth, an optical device, or other measuring instrument. FIG. 4A
illustrates some of the measurements that are taken. The rotational
axis of the fixture 10 is shown as 28. The mesial-distal angle with
respect to this axis is shown as 30, and the facial-lingual angle
with respect to this axis is shown as 32. The height from the
gumline to the top of the dental implant fixture is shown as
34.
[0033] Other measurements are shown in FIG. 4B. The width of the
gap between the teeth adjacent the tooth to be replaced is shown at
36. The facial-lingual offset, or the distance from the mid-point
of the dental implant fixture to the facial surface of the tooth,
is shown at 38. The mesial-distal offset is shown at 40. The
mesial-distal offset corresponds to one half of the difference in
the distances measured from the fixture to each adjacent tooth. For
example, if the distance from the dental implant fixture to the
first adjacent fixture is x and the distance from the dental
implant fixture to the second adjacent tooth is y, the
mesial-distal offset is (x-y)/2. Finally, the height to the
occlusal plane, or the distance from the gumline to the surface of
the tooth that contacts opposing teeth, is shown at 42.
[0034] Measurements of any or all of these parameters are taken to
guide the fabrication of an abutment that closely approximates the
size, shape and position of the tooth being replaced. In an
embodiment of the invention, the mesial-distal angle,
facial-lingual angle, rotational axis of a dental implant fixture
implanted at the site of desired tooth replacement, width,
facial-lingual offset, mesial-distal offset and height from the
gumline to the top of a dental implant are all measured. A
determination of the type of tooth being replaced (e.g., lateral
incisor, first bicuspid, etc.) is also made. From these
measurements, a customized abutment of the invention may be
prepared. In a preferred embodiment, other measurements, such as
the height to the occlusal plane, gingival profile (i.e., profile
of gumline with respect to the tooth) and dimensions (e.g., width,
height to occlusal plane, etc.) of the adjacent and opposing teeth
are also taken prior to preparing the customized abutment.
[0035] In a preferred embodiment, a model of a customized dental
abutment of the invention is generated by a parametrix solid
modeling system computer program, such as SolidWorks.TM.
manufactured by SolidWorks, Inc. (Concord, Mass.). A series of
average measurements for each of the various types of teeth are
used to pre-program the computer to generate baseline models. Such
average measurements may be found, for example, in Wheeler, Dental
Anatomy, Physiology and Occlusion (5th ed. 1974), incorporated by
reference herein.
[0036] A standard shape is generated for each of the various types
of teeth. The standard shape represents the average tooth shape for
the type of tooth being replaced. The collection of standard shapes
represents the inventory from which a Customized abutment is
contoured. For example, to generate a standard shape for a right
maxillary lateral incisor the shape shown in FIG. 5A is first drawn
using the computer program. Points in each plane of a
three-dimensional co-ordinate system are added and connected until
the shape approximates that shown in FIG. 5A. The top of this shape
is then removed along one plane of the model to give the shape
shown in FIG. 5B. To this shape is then added a frusto-conical
shape as shown in FIG. 5C. The interface between the abutment and
the dental implant fixture is then built into the model. As shown
in FIG. 5D, the interface may have a hexagonal shape. Further
refinements of the interface are shown in FIG. 5E. Finally, an
opening in the abutment model must be made for insertion of the
mechanism that secures the abutment to the dental implant fixture.
This step is shown in FIG. 5F. This model may then be modified
using the parametrix solid modeling system computer program to add
contours and other variations in the shape so that it more closely
approximates the contours of a natural tooth as shown in FIGS. 5G
and 5H. Other methods of generating a similar model by use of
parametrix solid modeling system computer program are possible.
[0037] The measurements taken at the site of desired tooth
replacement and the determination of the type of tooth being
replaced are then entered into the modeling program. The program
then compares the measurements taken of the site to the
pre-programmed standard shapes for the type of tooth being
replaced. If a particular measurement differs from the average
measurement for that tooth, the computer modifies the standard
shape to conform to the measurement taken of the site of desired
tooth replacement. The computer program also scales the model to
conform to the measurements of the site of desired tooth
replacement that are entered. In other words, the computer modifies
the model in accordance with the measurements that are entered
while maintaining proper geometry of the model.
[0038] The model generated by the computer is then used to create a
prototype of the customized abutment. A prototype, preferably made
of wax, of the abutment may be created, for example, on a Sanders
Prototype, Inc. Model Maker 6 Pro.RTM. rapid prototyping machine.
From this prototype a cast of the abutment is made. The abutment is
then fabricated from this cast, polished and sterilized, resulting
in the customized dental abutment of the invention.
[0039] Methods of the invention also relate to selection of a
customized dental abutment from an inventory of abutments. The
inventory is preferably a pre-programmed computer inventory. A
computer program, such as that described above, is used to generate
an inventory of abutments of various parameters by creating
versions of the type of tooth which vary according to the
measurements described above. By taking measurements of the site of
desired tooth replacement and determining the type of tooth to be
replaced, a model of an abutment can be selected from the
inventory. The measurements and tooth type are entered into the
computer pre-programmed with the inventory of abutments. The
measurements are compared to the available models for that tooth
type, and a model that most closely approximates the measurements
is selected. This model is then used to generate a prototype from
which a customized dental abutment may be cast, as described
above.
[0040] A customized dental abutment so fabricated is then sent to
the dental practitioner for installation into the dental implant
fixture implanted into the patient's jawbone. After the site of the
implanted dental fixture is healed, the customized dental abutment
of the invention is secured in place in the dental implant fixture
by, for example, screwing it into place in the dental implant
fixture. The use of a healing abutment is not required as described
in co-owned, co-pending U.S. Ser. No. 08/372,323, incorporated by
reference herein. A crown that approximates the size and color of
the natural dentition is attached to the abutment with an adhesive
and/or a lateral set screw. A dental technician sculpts the crown
with reference to the previously-prepared analog fixture and
abutment. The crown is sculpted from, for example, wax or ceramic.
The skilled artisan is aware that numerous methods may be used to
sculpt a crown from an analog fixture and abutment.
[0041] An dental restoration is therefore performed without the
high number of office visits required by standard methods, and
without the amount of cost and labor involved in standard methods.
Additional aspects and advantages of the invention are apparent
upon consideration of the foregoing. Accordingly, the scope of the
invention is limited only by the scope of the appended claims.
* * * * *