U.S. patent application number 15/833591 was filed with the patent office on 2018-06-07 for system and method for effective planning, visualization, and optimization of dental restorations.
This patent application is currently assigned to 3SHAPE A/S. The applicant listed for this patent is 3SHAPE A/S. Invention is credited to Tais Clausen, Rune FISKER, Karl-Josef Hollenbeck, Sune Jorgensen.
Application Number | 20180153659 15/833591 |
Document ID | / |
Family ID | 42635133 |
Filed Date | 2018-06-07 |
United States Patent
Application |
20180153659 |
Kind Code |
A1 |
FISKER; Rune ; et
al. |
June 7, 2018 |
SYSTEM AND METHOD FOR EFFECTIVE PLANNING, VISUALIZATION, AND
OPTIMIZATION OF DENTAL RESTORATIONS
Abstract
Disclosed is a method for planning, visualizing, and/or
optimizing dental restoration on at least a part of the
pre-prepared teeth of a patient, wherein said method include the
steps of: providing at least one 3D digital model of at least a
part of the pre-prepared teeth; designing at least one dental
restoration CAD model based on the 3D digital model of at least a
part of the pre-prepared teeth; providing at least one 3D digital
model of at least a part of the prepared teeth, where the prepared
teeth are provided by preparing the pre-prepared teeth by dental
restorative work, at least partly based on the dental restoration
CAD model; and aligning the 3D models of the pre-prepared and the
prepared teeth.
Inventors: |
FISKER; Rune; (Virum,
DK) ; Hollenbeck; Karl-Josef; (Kobenhavn o, DK)
; Jorgensen; Sune; (Roskilde, DK) ; Clausen;
Tais; (Klagshamn, SE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
3SHAPE A/S |
Copenhagen K |
|
DK |
|
|
Assignee: |
3SHAPE A/S
Copenhagen K
DK
|
Family ID: |
42635133 |
Appl. No.: |
15/833591 |
Filed: |
December 6, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13256452 |
Dec 6, 2011 |
9861457 |
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15833591 |
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PCT/DK10/50063 |
Mar 18, 2010 |
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13256452 |
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61161903 |
Mar 20, 2009 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61C 5/77 20170201; A61C
13/0004 20130101; A61C 5/20 20170201 |
International
Class: |
A61C 13/00 20060101
A61C013/00; A61C 5/77 20170101 A61C005/77 |
Claims
1. (canceled)
2. A computer program product embodied in a non-transitory computer
readable medium, the computer program product comprising computer
readable program code being executable by a hardware data processor
to cause the hardware data processor to: obtain a facial 3D digital
model of the patient with at least a part of the teeth being
visible; obtain a dental restoration CAD model; align the dental
restoration CAD model with the visible teeth in the facial 3D
digital model; and visualize a dental restoration along with the
patient's face by displaying the dental restoration CAD model
aligned with the visible teeth in the facial 3D digital model.
3. The computer program product according to claim 2, the computer
readable program code being executable by the hardware data
processor to cause the hardware data processor to cut and/or remove
teeth from the obtained facial 3D digital model.
4. The computer program product according to claim 2, the computer
readable program code being executable by the hardware data
processor to cause the hardware data processor to obtain a 3D
digital model of at least a part of the patient's pre-prepared
teeth.
5. The computer program product according to claim 4, the computer
readable program code being executable by the hardware data
processor to cause the hardware data processor to align the 3D
digital model of the pre-prepared teeth with the visible teeth in
the facial 3D digital model.
6. The computer program product according to claim 2, wherein the
dental restoration CAD model comprises at least one dental
restoration 3D digital model.
7. The computer program product according to claim 6, the computer
readable program code being executable by the hardware data
processor to cause the hardware data processor to design the at
least one dental restoration 3D digital model based on the 3D
digital model of the pre-prepared teeth and/or on the 3D facial
model.
8. The computer program product according to claim 2, the computer
readable program code being executable by the hardware data
processor to cause the hardware data processor to predict a change
in facial soft-tissue around the patient's mouth resulting from
restorative work on the patient's teeth.
9. The computer program product according to claim 6, the computer
readable program code being executable by the hardware data
processor to cause the hardware data processor to visualize the
dental restoration 3D digital model aligned in the facial model 3D
digital model on a computer screen.
10. A computer program product embodied in a non-transitory
computer readable medium, the computer program product comprising
computer readable program code being executable by a hardware data
processor to cause the hardware data processor to: obtain a facial
3D digital model of the patient with at least a part of the teeth
being visible; obtain a dental restoration CAD model; align the
dental restoration CAD model with the visible teeth in the facial
3D digital model; and visualize a dental restorative work on the
patient by displaying the dental restoration CAD model aligned with
the visible teeth in the facial 3D digital model.
11. The computer program product according to claim 10, the
computer readable program code being executable by the hardware
data processor to cause the hardware data processor to modify
and/or optimize the dental restoration CAD model.
12. A method for visualizing proposed restorations along with the
patient's face, the method comprising: obtaining a facial 3D
digital model of the patient with at least a part of the teeth
being visible; obtaining a dental restoration CAD model; aligning
the dental restoration CAD model with the visible teeth in the
facial 3D digital model; and visualizing proposed restorations
along with the patient's face by displaying the dental restoration
CAD model aligned with the visible teeth in the facial 3D digital
model.
13. The method according to claim 12, wherein the method comprises
cutting and/or removing teeth from facial 3D digital model
14. The method according to claim 12, wherein obtaining the dental
restoration CAD model comprises designing at least one dental
restoration 3D digital model.
15. The method according to claim 14, wherein the dental
restoration 3D digital model at least partly is designed based on
biometric information for optimizing the aesthetic impression of
the dental restoration.
16. The method according to claim 15, wherein the biometric
information is derived from the facial 3D digital model.
17. The method according to claim 15, wherein biometric information
relates the facial midline, the arch midline, the incisal plane,
the interpupillary line, the degree of maxillary anterior tooth
display (Morley ratio), the upper lip drape, and/or the gingival
display.
18. The method according to claim 12, the method comprising
obtaining a 3D digital model of at least a part of the patient's
pre-prepared teeth and aligning the 3D digital model of the
pre-prepared teeth with the visible teeth in the facial 3D digital
model.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S.
application Ser. No. 13/256,452, filed on Dec. 6, 2011, which is a
U.S. national stage application of International Application No.
PCT/DK10/50063, filed on Mar. 18, 2010, which claims the benefit of
U.S. Provisional Application No. 61/161,903, filed on Mar. 20,
20009. The entire contents of each of U.S. application Ser. No.
13/256,452, International Application No. PCT/DK10/50063, U.S.
Provisional Application No. 61/161,903 are hereby incorporated
herein by reference in their entirety.
TECHNICAL FIELD
[0002] The present invention relates to a system and a method for
planning dental restorative work. The invention furthermore relates
to a system and a method for interactive CAD design and realistic
3D presentation and visualization of dental restorations and
subsequent physical realization by means of CAM.
BACKGROUND
[0003] In dental practice, diagnostic wax-ups are created to
visualize and plan restorative treatment, e.g., veneers or crowns
on the anterior/front teeth. Diagnostic wax-ups are traditionally
created in wax on gypsum casts by the dental laboratory for the
dentist who uses it for treatment planning as well as for
visualization and discussion of the restorative result with the
patient. The dialog between dentist and patient is an important
tool for improved patient satisfaction and often enables more
expensive treatments. To transfer the design from the diagnostic
wax-up to the patient's teeth, the dental technician typically
looks at the original diagnostic wax-up and manually tries to
replicate this design for the real restorations, incorporating
potential comments from the dentist and the patient. This manual
replication process is both costly, possibly inaccurate, and time
consuming.
[0004] Because of the manual labor involved, diagnostic wax-ups are
generally expensive, often several hundred US dollars. Creating a
wax-up model is also time-consuming, such that the patient
generally has to return for another appointment to evaluate it.
Because diagnostic wax-ups are models of teeth only, they also fail
to convey the full aesthetic impact of a restorative treatment. The
visual impression of a patient's smile is also determined by the
gingiva and the entire face [1]. Furthermore, a free standing
wax-up model cannot convey the lighting to which teeth are subject
to inside the mouth. In the field of orthodontics, treatment
planning has more commonly involved 3D models of both the teeth and
the face, or even the head. Data sources include 2D color pictures
of the face and CT scans of the head [2, 3].
[0005] WO 2006/065955 discloses methods and systems for orthodontic
treatment including a method for generating a photo-realistic image
of a predicted result of a dental treatment on a patient, the
method comprising: acquiring one or more images of the patient's
pre-treatment face and teeth; generating a 3D digital model of the
patient's pre-treatment face and teeth from the images of the
patient's pre-treatment face and teeth; acquiring a 3D digital
model of the patient's pre-treatment tooth arch; acquiring a 3D
digital model of the patient's predicted tooth arch resulting from
the treatment; generating a 3D digital model of the patient's
predicted face and teeth from the 3D digital models of the
patient's pre-treatment face and teeth, pre-treatment tooth arch,
and predicted tooth arch; and rendering a photo-realistic image
from the 3D digital model of the patient's predicted face and
teeth.
[0006] WO 2004/098378 relates to orthodontic treatment and
discloses a system for use in diagnosis and planning treatment of a
human patient, comprising: a general purpose computer system having
a processor and a user interface; a memory accessible to said
general purpose computer system storing a) a first set of digital
data representing patient craniofacial image information obtained
from a first imaging device, and b) a second set of digital data
representing patient craniofacial image information obtained from a
second image device different from said first image device, said
first and second sets of data representing at least in part common
craniofacial anatomical structures of said patient, at least one of
said first and second sets of digital data including data
representing the external visual appearance or surface
configuration of the face of the patient; and a set of computer
instructions stored on a machine readable storage medium accessible
to said general purpose computer system, wherein said set of
instructions comprises instructions for causing said general
computer system to: 1) automatically, and/or with the aid of
operator interaction, superimpose said first set of digital data
and said second set of digital data so as to provide a composite,
combined digital representation of said craniofacial anatomical
structures in a common coordinate system; 2) displaying said
composite, combined digital representation of said craniofacial
anatomical structures to a user of said system.
[0007] Thus, in the field of orthodontics, treatment planning
involving 3D models of both the teeth and the face are known.
[0008] US 2008/153061 discloses a method for planning and
performing dental treatments, comprising: an acquisition phase of a
set of data relating to the position, to the conformation and to
the dimension of at least one site inside the oral cavity of a
patient who has to undergo a dental treatment and relating to the
conformation of at least one portion of the face of said patient; a
design phase of a virtual prototype of at least one dental
prosthesis that can be fitted at said site during said treatment
starting from said set of data and by means of a software program
implemented on a computer; a determination phase, by means of said
software program and starting from said set of data and from said
virtual prototype of the dental prosthesis, of at least one virtual
model suitable for visually reproducing said portion of the face
following the fitting of said dental prosthesis; a preparation
phase of said site by means of a dental instrument, with the
assistance of said software and starting from said virtual
prototype of the dental prosthesis and from said virtual model,
before the installation and the manufacture of said dental
prosthesis.
[0009] US 2008/153061 does not describe how to combine the various
sources of geometry information, especially of the teeth, which are
represented in both the scan of the face and that of the oral
cavity. Neither does US 2008/153061 describe how to transfer the
results of the design phase to the actual post-preparation dental
geometry. Furthermore, US 2008/153061 assumes the reading phase of
the virtual impression to be performed by the same dental
instrument that executed the preparation of the oral site.
[0010] WO 2009/091438 discloses a method for designing a custom
dental device, comprising the steps of: obtaining a set of
time-based 3-dimensional images of the oral anatomy of a person
during jaw motion; obtaining 3-dimensional data of a dental object
of the person; registering the 3-dimensional data of the dental
object to at least one of the time-based 3-dimensional images;
using the time-based 3-dimensional images and registered
3-dimensional data to design a dental device.
[0011] WO 2009/091438 assumes that the 3-dimensional images be
acquired at a rate of 50 per second; however, no such scanner
exists at present nor is it disclosed. Furthermore, it appears
unrealistic that the supposedly required accuracy of tracking
dental objects, where the accuracy is about 20 m, can be achieved
with any of the technologies referenced, nor is any new appropriate
technology disclosed.
[0012] In all, it remains a problem to provide improved systems and
methods for planning and visualizing dental restorations on teeth
of a patient.
SUMMARY
[0013] Dental restorations, both indirect restorations and e.g.
partial dentures and implant-retained structures are more and more
often designed using CAD software and a digital model of the
patient's teeth, a digital model usually obtained by means of a 3D
scanner. After design in the CAD software, the restoration can be
produced by CAM software. Present dental CAD software, however,
does not support interaction with the patient, if anything because
the present CAD modeling process generally starts from prepared
teeth--too late for the patient to influence the treatment to a
significant degree. Thus, a main object of the invention is to
provide digital design of dental restorations at an earlier stage
of the design process.
[0014] This is achieved by a method for planning dental restoration
on at least a part of the pre-prepared teeth of a patient, wherein
said method comprises the steps of: [0015] providing at least one
3D digital model of at least a part of the pre-prepared teeth;
[0016] designing at least one dental restoration CAD model based on
the 3D digital model of at least a part of the pre-prepared teeth;
[0017] providing at least one 3D digital model of at least a part
of the prepared teeth, where the prepared teeth are provided by
preparing the pre-prepared teeth by dental restorative work,
preferably at least partly based on the dental restoration CAD
model; and [0018] aligning the 3D models of the pre-prepared and
the prepared teeth.
[0019] Thus it is an advantage that the method provides alignment
or merging of multiple 3D data sources and exploitation of the
results of pre-treatment analysis and planning.
[0020] It is an advantage of the method that the dentist can design
and show a dental restoration CAD model, which is a virtual model,
to the patient, before the dentist starts preparing the patient's
teeth, such that the patient can see what the dental restoration
will look like. Since the dental restoration CAD model is based on
the 3D digital model of patient's pre-prepared teeth, the dental
restoration will give a true image of how the dental restoration
will really look. Thus the patient has a chance to say if he wishes
the dental restoration to have a different shape, size etc. before
the dentist starts preparing the patient's tooth/teeth.
[0021] Then after the dentist has prepared the patient's teeth to
receive or fit to the agreed dental restoration, a 3D digital model
of the prepared teeth is provided. There is now a 3D model of the
pre-prepared teeth and a 3D model of the prepared teeth, and these
two models are then aligned. When aligning the two models it is
possible to obtain a dental restoration with a perfect fit because
both the pre-prepared teeth and the prepared teeth are used in the
design such that the original teeth and the prepared teeth are
taken into account.
[0022] The pre-prepared teeth can be the patient's teeth before any
treatment has been applied. However, the pre-prepared teeth may
also be the patient's teeth prior to the preparation work that is
often required prior to a dental restoration. Therefore the
pre-prepared teeth may have received some (typically minor)
treatment, such as cleaning, polishing, minor grinding and/or the
like, but the pre-prepared teeth have not been prepared for a
dental restoration. A preparation for a dental restoration
typically requires grinding, drilling, removal, endodontic
treatment and/or the like, of relevant tooth/teeth. All in all: by
the present invention a possible dental restoration can be provided
by means of CAD with basis in a 3D model of the pre-prepared
teeth.
[0023] Thus embodiments of the invention relates to planning,
visualizing, optimizing and/or executing dental restorative work by
means of CAD.
[0024] Prior to dental restorative work relevant tooth/teeth are
prepared. Thus, the 3D model of the pre-prepared teeth may also be
prepared. In a further embodiment of the invention a dental
preparation CAD model is designed, preferably at least partly based
on the model of the pre-prepared teeth.
[0025] Thus, the present invention provides procedures to
effectively transfer pre-preparation design work to the actual
preparation procedure, and even to the post-preparation design
phase. This is illustrated in FIG. 1. And furthermore, duplicate
design work for pre-prepared and prepared teeth is avoided.
[0026] A related objective is to avoid the manual production of
diagnostics wax-ups in relation to planning, evaluation and
execution of dental restorations.
[0027] The prior art documents related to orthodontics do not
disclose designing dental restorations, since orthodontics is
related to moving teeth by means of appliances, such as dental
braces, headgear etc., and therefore in orthodontics no dental
restorations are designed.
[0028] Models, such as virtual 3D models, mentioned in relation to
orthodontics are models of the configurations or arrangements of
teeth in the different steps in an orthodontic treatment and
planning, because the teeth will be moved stepwise over longer time
by means of the appliances.
[0029] The prior art document US 2008/0153061 does for example not
disclose the steps of aligning the 3D models of the pre-prepared
and the prepared teeth.
[0030] In some embodiments the method further comprises
transferring the design of the dental restoration CAD model to the
model of the prepared teeth. When transferring the design of the
dental restoration CAD model to the model of the prepared teeth,
the design can be adjusted to fit the model automatically and/or
manually.
[0031] A further object of the invention is to visualize proposed
restorations, possibly along with the patient's face. This is
achieved by providing a facial 3D digital model of the patient,
preferably with at least a part of the teeth being visible and/or
exposed, preferably provided by means of scanning at least a part
of the face of the patient, preferably optical scanning.
[0032] A further embodiment of the invention comprises the step of
at least partly aligning the 3D model of the pre-prepared teeth
and/or the dental restoration CAD model with the visible teeth in
the facial 3D model.
[0033] In a further embodiment of the invention the dental
restoration CAD model is at least partly designed based on the
facial 3D model.
[0034] A further embodiment of the invention comprises the step of
providing a preparation guide for the dentist prior to preparing
the teeth, said preparation guide preferably at least partly based
on the dental preparation CAD model.
[0035] In a further embodiment of the invention said preparation
guide provides assistance in relation to lengthening of crown(s),
location and/or type of the margin, and/or the like, and wherein
the generation of said preparation guide is at least partly based
on the dental restoration CAD model and/or the 3D model of the
pre-prepared teeth and/or the dental preparation CAD model and/or
segmentation of said models.
[0036] In a further embodiment of the invention said preparation
guide comprises instructions for execution of a machine generated
preparation and/or preparation model.
[0037] In a further embodiment of the invention said preparation
guide comprises a dental model of the preparation, such as a gypsum
model and/or a wax-up model, such as a marked-up dental model.
[0038] A further embodiment of the invention comprises the step of
transferring the design of the dental restoration CAD model
comprises aligning the dental preparation CAD model with the 3D
model of the prepared teeth.
[0039] In a further embodiment of the invention aligning is at
least partly based on detecting and/or demarcating and/or aligning
margin lines of the models.
[0040] In a further embodiment of the invention transferring the
design of the dental restoration CAD model comprises morphing part
of the dental restoration CAD model to the 3D model of the prepared
teeth.
[0041] In a further embodiment of the invention morphing is applied
near the margin line of the dental restoration CAD model and/or the
3D model of the prepared teeth.
[0042] In a further embodiment the impact of morphing is highest
near the margin line of the dental restoration CAD model and/or the
3D model of the prepared teeth, with decreasing impact of the
morphing when increasing the distance to the margin line.
[0043] A further embodiment of the invention, the step of
transferring the design of the dental restoration CAD model
comprises creating an inner surface of the dental restoration CAD
model as an offset to the 3D model of the prepared teeth, said
offset preferably in the occlusal/incisal direction from the margin
line of the 3D model of the prepared teeth.
[0044] In a further embodiment of the invention said offset is
provided automatically.
[0045] In a further embodiment of the invention a significant part
of the outer surface of the dental restoration CAD model is
maintained when transferred to the 3D model of the prepared teeth,
the contour of the inner surface of the dental restoration CAD
model is substantially similar to the outer surface of the 3D model
of the prepared teeth and the margin line area of the dental
restoration CAD model and the 3D model of the prepared teeth are
morphed together.
[0046] Yet a further embodiment of the invention comprises the step
of transferring the design of the dental restoration CAD model
comprises morphing the dental preparation CAD model with the 3D
model of the prepared teeth, thereby providing a transformation of
the dental preparation CAD model to the 3D model of the prepared
teeth, and subsequently applying this transformation to the dental
restoration CAD model.
[0047] A further embodiment of the invention comprises the step of
modifying the design of the dental restoration CAD model subsequent
to the step of transferring said dental restoration CAD model to
the 3D model of the prepared teeth.
[0048] Yet another embodiment of the invention relates to a method
for planning, visualizing, and/or optimizing dental restorative
work on at least a part of the teeth of a patient, said method
comprising the steps of: [0049] providing a 3D digital model of at
least a part of the face of the patient, preferably with at least a
part of the patient's teeth being visible and/or exposed,
preferably provided by means of optically scanning at least a part
of the face of the patient, [0050] obtaining at least one 3D
digital model of at least a part of the prepared teeth, where the
prepared teeth are prepared by dental restorative work, [0051]
aligning the 3D model of the prepared teeth with the visible teeth
in the 3D facial model, and [0052] designing at least one dental
restoration CAD model based on the 3D model of the prepared teeth
and at least partly based on the 3D facial model.
[0053] In a further embodiment of the invention the 3D model of the
pre-prepared and/or the 3D model of the prepared teeth are provided
by means of scanning, such as scanning intra orally, scanning an
impression of the teeth and/or the antagonist, scanning a cast of
the teeth and/or the antagonist, and/or the like scanning
methods.
[0054] Yet a further embodiment of the invention comprises the step
of calculating margin lines of the 3D models.
[0055] In a further embodiment of the invention the 3D facial model
face, the 3D model of the pre-prepared teeth and/or 3D model of the
prepared teeth and/or the dental restoration CAD model and/or the
dental preparation CAD model comprises information of geometry
and/or texture (color).
[0056] In a further embodiment of the invention color is detected
by means of at least one color sensitive sensor and/or by means of
stacking of color channels.
[0057] In a further embodiment of the invention the 3D facial model
is provided by means of aligning and/or combining multiple
sub-scans of the face, preferably sub-scans provided from different
angles.
[0058] In a further embodiment of the invention at least part of
the sub-scans are at least partially overlapping.
[0059] In a further embodiment of the invention at least a part of
the sub-textures of at least a part of the sub-scans are color
adjusted and/or color interpolated, such as by texture weaving, to
provide the texture of the 3D facial model.
[0060] In a further embodiment of the invention at least part of
the hair of the patient is powdered with a reflective powder.
[0061] In a further embodiment of the invention silhouettes from
multiple sub-scans are extruded and subsequently intersected to
provide a visual hull approximation.
[0062] Yet a further embodiment of the invention comprises the step
of cutting and/or removing at least a part of the teeth from the 3D
facial model.
[0063] In a further embodiment of the invention design of the
dental restoration CAD model is at least partly based on biometric
information for optimizing the aesthetic impression of the dental
restoration, biometric information such as degree of maxillary
anterior tooth display (Morley ratio), upper lip drape and gingival
display.
[0064] In a further embodiment of the invention wherein the facial
midline is substantially aligned with the arch midline, and/or the
incisal plane and the interpupillary line are provided
substantially parallel.
[0065] In some embodiments of the invention the face scanner is
used to measure features of the face of the patient, such as the
facial midline, the arch midline, the incisal plane, and/or the
interpupillary line.
[0066] Yet a further embodiment of the invention comprises the step
of providing a least one X-ray image of at least a part of the
head, the jaw, the pre-prepared and/or the prepared teeth.
[0067] In a further embodiment of the invention multiple X-ray
images obtained from different angles are combined to provide a 3D
X-ray model.
[0068] In a further embodiment of the invention the 3D X-ray model
is aligned with and/or visualized along one or more of the 3D
models and/or the CAD models.
[0069] In a further embodiment of the invention automatic and/or
semi-automatic assistance is provided in the design of the dental
restoration CAD model and/or the dental preparation CAD model,
assistance such as automatic suggestions, evaluation of basic rules
and requirements and/or the like, requirements such as medical
and/or biologic requirements.
[0070] In a further embodiment of the invention a library of
standard restorations and/or standard preparations is provided when
designing the dental restoration CAD model and/or the dental
preparation CAD model, a library such as a library of CAD
models.
[0071] Yet a further embodiment of the invention comprises the step
of estimating the strength of a planned dental restoration, such as
estimating by means of finite-element simulation.
[0072] A further embodiment of the invention comprises the step of
visualizing the dental restoration CAD model, for example for the
patient, dentist and/or dental technician.
[0073] In a further embodiment of the invention the dental
restoration CAD model is visualized side-by-side, along and/or on
top of the model of the pre-prepared teeth.
[0074] A further embodiment of the invention comprises the step of
visualizing the dental restoration CAD model aligned in the facial
model.
[0075] A further embodiment of the invention comprises the step of
predicting and/or visualizing the facial soft-tissue-change
occurring as a result of the dental restorative work.
[0076] In a further embodiment of the invention visualization is
provided in 3D, such as visualization of 3D models and CAD
models.
[0077] In a further embodiment of the invention visualization is
provided by means of at least one computer screen and/or by means
of manufacturing of at least one diagnostic wax-up. Thus, the 3D
models and/or the CAD models can be presented on a computer screen,
however the models may also be physically realized e.g. by 3D
printing in gypsum or wax.
[0078] In a further embodiment of the invention visualization is
provided over a computer network, such as the internet.
[0079] Yet a further embodiment of the invention comprises the step
of predicting and/or visualizing the facial soft-tissue-change
occurring as a result of the dental restorative work.
[0080] Yet a further embodiment of the invention comprises the step
of at least partially segmenting teeth and tissue, such as
gingival, in the 3D model of the pre-prepared teeth and/or in the
3D model of the prepared teeth and/or in the 3D facial model.
[0081] In a further embodiment of the invention segmentation is at
least partly provided by means of a computer implemented algorithm,
such as a shortest-path algorithm applied on a 3D matrix
representing curvature of the tooth surface.
[0082] In a further embodiment of the invention segmentation is at
least partly based on color information in the 3D model(s).
[0083] A further aspect of the invention relates to a method for
planning, visualizing, and/or optimizing dental restoration on at
least a part of the pre-prepared teeth of a patient, where said
method comprises the steps of: [0084] providing at least one 3D
digital model of at least a part of the pre-prepared teeth; [0085]
designing at least one dental restoration CAD model based on the 3D
digital model of at least a part of the pre-prepared teeth; [0086]
where the method further comprises the step of: [0087] simulating
and estimating dynamic occlusal interferences, and wherein said
interferences are deduced at least partly from a plurality of scans
that record said patient's jaw articulation by tracking at least
one reference object fixed to the patient's teeth.
[0088] Yet a further embodiment of the invention comprises the step
of calculating the articulation of the jaw and thereby simulating
and/or estimating dynamic occlusal interferences.
[0089] In some embodiments of the invention the face scanner is
used to measure 3D movements of the jaws and face of the patient in
real time.
[0090] In some embodiments of the invention the face scanner is
used to measure the position of the upper jaw and/or lower jaw with
respect to the skull. Thus the face scanner may then replace a
face-bow, which is traditionally used for this measurement.
[0091] Thus the face scanner can be used to measure planes of the
face, such as centric determination or the midline, it can be used
to measure jaw movement, and/or it can be used to measure the
attachment and/or movement of the jaws relative to the rest of the
skull.
[0092] Thus the measured jaw motions, which are the physically true
motions or movements, are used to simulate the movement in a
dynamic virtual articulator, such that dental restorations can be
designed, where the dental restorations have improved functionality
and aesthetics. Thus the face scanner can perform the relevant
measurements for providing a dental restoration, and thereby
replacing the use of e.g. face-bows etc.
[0093] In a further embodiment of the invention calculation and/or
estimation of the articulation of the jaw and/or the dynamic
occlusal interferences is at least partly based on a plurality of
face scans and at least one 3D model of the pre-prepared and/or
prepared teeth, a 3D model that comprises the antagonist. For
optimal accuracy and precision, it is advantageous to fix one or
more reference spheres or objects to the teeth.
[0094] Yet a further embodiment of the invention comprises the step
of interactively modifying and/or optimizing the design of the
dental restoration CAD model, preferably based on input from a
dentist and/or the patient and/or from considerations relating to
aesthetic appearance, biometrics, medial and/or biological rules
and/or requirements, estimation of strength, soft-tissue change,
occlusal interferences, color issues, cost of restoration and/or
the like.
[0095] Design and/or design modifications of the dental restoration
CAD model can be provided by a dentist and/or dental technician in
cooperation with the patient. However, with digital models the
involved patients do not have to be at the same location because
the models can be distributed, presented and/or visualized via a
computer network. Thus, in a further embodiment of the invention
wherein interactive modification and optimization of the dental
restoration CAD model is provided across a computer network, such
as patient, dentist and/or dental technician being located at
different geographic locations. E.g. the patient may be at home
while the dentist is presenting the dental restoration CAD model,
such as via a web page. Or the dentist and the patient may be at a
dental clinic, together evaluating a dental restoration model for
the patient provided by a dental technician at a dental lab in
another location.
[0096] A further embodiment of the invention comprises the step of
evaluating and/or validating a preparation guide and/or a set of
prepared teeth, preferably at least partly based on a 3D model of
said prepared teeth.
[0097] In a further embodiment of the invention evaluation and/or
validation comprises estimating and/or evaluating a proposed dental
restoration, choice of materials, choice of restorative method,
and/or the like.
[0098] In a further embodiment of the invention a dental
restoration can be one or more inlays, onlays, veneers, crowns,
bridges or combinations thereof and/or a dental restoration can be
a removable partial denture framework and/or an implant-retained
structure.
[0099] In another embodiment of the invention planning,
visualizing, optimizing and/or executing dental restorative work is
combined with planning, visualizing, optimizing and/or executing of
plastic surgery applied to the head and/or face.
[0100] In a further embodiment the method further comprising
planning, visualization, and/or optimization of at least one "snap
on", wherein a "snap-on" CAD model is created by subtracting the 3D
model of the pre-prepared teeth from the dental restoration CAD
model.
[0101] Yet a further embodiment of the invention comprises the step
of manufacturing of a dental restoration for the prepared teeth
based on the dental restoration CAD model, preferably by means of
CAM.
[0102] A further embodiment of the invention comprises the step of
manufacturing of a diagnostic wax-up based on the dental
restoration CAD model, preferably by means of CAM.
[0103] A further embodiment of the invention comprises the step of
manufacturing of a preparation guide for the prepared teeth based
on the dental preparation CAD model, preferably by means of
CAM.
[0104] A further embodiment of the invention comprises the step of
manufacturing of a diagnostic wax-up based on the dental
preparation CAD model and/or the preparation guide, preferably by
means of CAM.
[0105] In a further embodiment of the invention CAM instructions
for manufacturing of the dental restoration are provided and/or
distributed by means of a computer network, such as transferred to
a processing centre via the internet.
[0106] In a further embodiment of the invention any listed step at
least partly is provided by means of CAD or can be provided by
means of CAD.
[0107] In a further embodiment the method further comprises
designing a temporary crown, where the temporary crown is derived
from the CAD design.
[0108] A further embodiment of the invention relates to design
and/or manufacture of snap-ons.
[0109] The entire process of deciding upon--preferably
interactively with the patient--and then designing a dental
restoration is now fully digitally supported.
[0110] The invention furthermore relates to a system comprising
means for carrying out any of the listed methods.
[0111] The invention furthermore relates to a computer program
product having a computer readable medium, said computer program
product comprising means for carrying out any of the listed
methods.
[0112] A preferred embodiment of this invention allows for
interactive design of restorative treatment, thus increasing the
chance for complete patient satisfaction. In terms of interactivity
this invention is based on 3D models, contrary to for example U.S.
Pat. No. 6,786,726 that only relates to 2D digital images.
[0113] One embodiment of the invention provides a method and a
system to plan and execute dental restorative treatment mainly
relying on 3D data and without the need for a physical diagnostic
wax-up. Preferably, also color 3D scans of the patient's head are
obtained and used within the planning process, making it even more
comprehensive and realistic. Methods described this application can
be interactive between the patient and the dentist, thus
ascertaining the patient's accept of the proposed treatment. As
another advantage, the 3D data obtained in the pre-treatment phase
can be exploited when the restoration is actually designed for
manufacture by CAM.
[0114] In one embodiment, the invention concerns a system and
method for planning dental restorative treatment and designing a
dental restoration based on a 3D digital model of the patient's
teeth in the pre-preparation state, where this planning and design
is implemented in software only. Thereby, the system and method has
the advantages of a diagnostic wax-up without its disadvantages of
high costs and tedious and time-consuming manufacture. The dentist
can even design the restoration interactively with the patient.
Once a design has been decided on, the dentist will generally
prepare the teeth accordingly, and generate another 3D model of the
prepared teeth. The final design will be based on the prepared
state, but can exploit the pre-preparation design.
[0115] Optionally in said embodiment, the invention includes a
system and a method to obtain a colored 3D model of the patient's
head. This latter model is usually obtained with another type of
scanner, and it need not have the same high level of detail as the
3D model of the teeth. To visualize the effects of treatment, the
teeth in the head model are replaced by the CAD-designed teeth
(i.e., the teeth as they would appear post-treatment), using some
kind of alignment technique and information from the 3D model of
the teeth prior to CAD design. The result is a composite 3D model
of head and teeth that can visualize the effect of potential
restorative work even better than a 3D model of teeth alone.
[0116] In another embodiment of the invention, the colored 3D model
of the patient's head is required, whereas the digital model of
teeth in their pre-preparation state is not. The design of the
restoration after a model of the prepared teeth is obtained can
take advantage of the information in the face model in the same way
as the previous embodiment.
[0117] The present invention relates to different aspects including
the method described above and in the following, and corresponding
methods, systems, devices, uses, and/or product means, each
yielding one or more of the benefits and advantages described in
connection with the first mentioned aspect, and each having one or
more embodiments corresponding to the embodiments described in
connection with the first mentioned aspect and/or disclosed in the
appended claims.
[0118] In particular, disclosed is a system for planning,
visualizing, and/or optimizing dental restoration on at least a
part of the pre-prepared teeth of a patient, wherein said system
comprises: [0119] means for providing at least one 3D digital model
of at least a part of the pre-prepared teeth; [0120] means for
designing at least one dental restoration CAD model based on the 3D
digital model of at least a part of the pre-prepared teeth; [0121]
means for providing at least one 3D digital model of at least a
part of the prepared teeth, where the prepared teeth are provided
by preparing the pre-prepared teeth by dental restorative work, at
least partly based on the dental restoration CAD model; and [0122]
means for aligning the 3D models of the pre-prepared and the
prepared teeth.
[0123] Definitions
[0124] A 3D model (aka a 3D digital model) can be either point
clouds, surface (faceted/meshed), or volumetric. Faceted/meshed
models are preferred over point clouds, but faceted/meshed models
can be generated from point clouds, for example by triangulation.
Volumetric models can be obtained with a scanner applying
penetrating radiation, such as CT scanners.
[0125] A restoration CAD model is a virtual computer model of a
restoration. Similarly: a preparation CAD model is a virtual
computer model of a preparation. CAD models are created in a
software program and can be based on one or more 3D models of the
patient teeth. Thus, whereas a 3D model is typically a digital
representation of a physical object, a CAD model is a virtual
digital model, however possibly at least partly comprising a
digital representation of at least a part of a physical object.
[0126] A restoration is a classical fixed restoration such as
inlays/onlays, veneers, crowns, bridges, implant-retained
structures etc, but by analogy also removable restorations such as
dentures. A restoration requires dental restorative work.
[0127] A preparation guide is a recommended procedure to execute a
dental preparation. It may be in the form of documents, audiovisual
material, or physical artifacts such as example dental models. It
may contain information concerning which equipment to use and how
to use it. Thus a preparation guide is typically directed at a
dentist, a dental technician, a dental lab and/or the like. A
preparation guide may comprise (software) instructions that can be
executed by a machine used for the preparation.
[0128] A patient is the person for whom a restoration is designed.
There may be medical indications for dental treatment of this
patient, but also cosmetic considerations can be a relevant
motivation for having a dental restoration designed.
BRIEF DESCRIPTION OF DRAWINGS
[0129] The above and/or additional objects, features and advantages
of the present invention, will be further elucidated by the
following illustrative and non-limiting detailed description of
embodiments of the present invention, with reference to the
appended drawings, wherein:
[0130] FIG. 1: Motivation for this invention, outline of flowchart
with graphical illustrations for clarity.
[0131] FIG. 2: Detailed flow chart for variant V1 of the method
described in this invention.
[0132] FIG. 3: Detailed flow chart for variant V2 of the method
described in this invention.
[0133] FIG. 4: Sagital section of a schematic tooth, visualizing
various steps of the method described in this invention.
[0134] FIG. 5: Zoomed sagital section of a schematic tooth,
illustrating step the transfer of the pre-preparation design to the
prepared teeth.
[0135] FIG. 6: Graphical representation of some steps in this
invention.
[0136] FIG. 7: Example screen snapshots of CAD software showing
face model with part of the smile cut out and model of restoration
(affecting teeth 6-11) and tissue (segmented) aligned to that of
the face. For the sake of being able to distinguish face scan and
restoration model in this Figure, the color of the restoration was
intentionally not attempted matched that of the teeth in the face
scan (this is visible even in the black-and-white pictures). (a):
anterior view, (b): lateral view.
DETAILED DESCRIPTION
[0137] In the following description, reference is made to the
accompanying figures, which show by way of illustration how the
invention may be practiced.
[0138] In one embodiment of the invention (in the following termed
"V1" and illustrated in the flow chart in FIG. 2) a pre-treatment
(pre-prepared) 3D model of the patient's teeth is used, preferably
obtained with a 3D scanner. Optionally, another 3D model of the
patient's face (possibly obtained with another type of scanner) is
exploited for optimal alignment and/or aesthetic look of the
restoration.
[0139] In another embodiment of the invention (in the following
termed "V2" and illustrated in the flow chart in FIG. 3), the 3D
facial model is required, while the pre-treatment 3D model is
optional.
[0140] Both V1 and V2 may comprise similar steps, however in a
different combination and with slight differences. Optional steps
and models in V1 and V2 are indicated by dashed borders in the
flowchart elements. Some steps are optional only in V1 or V2. Some
steps may be implemented in software, while others may represent
manual work and/or application of machinery. The software is
preferentially a single program, for optimal ease of use.
[0141] Some steps are also illustrated graphically in FIGS.
4-7.
[0142] Step 1: Obtain 3D digital model of pre-treatment teeth and
gingiva (required in V1, not applicable in V2):
[0143] There are several commercial systems available for obtaining
3D digital models 100 of teeth (e.g., Cadent iTero, 3M ESPE Lava,
3Shape D640). Among these are intra-oral scanners and scanners for
dental impressions or casts thereof (e.g., 3Shape D640). Scanners
can be for example be optical scanners (laser, structured light).
Guidelines in the relevant scanner manufacturer's operations manual
should be followed for obtaining the 3D model 100. This model 100
will in the following also be denoted as the pre-preparation model.
Its contour in FIG. 4 is C100.
[0144] Potentially, scanners with penetrating radiation such as
(cone beam) CT scanners (Imaging Science International's i-CAT,
Kodak/Imtec's Iluma) can be used to obtain model 100. They have the
advantage of providing volumetric models showing also decay inside
the teeth, while disadvantages include concerns about radiation
dose or high price of treatment. A teeth scan is shown in FIG. 6,
step 1.
[0145] Step 2: Segment pre-prepared teeth from gingiva (optional in
V1, not applicable in V2): Optical scanners generally obtain a 3D
digital model of an object's surface. While this model describes
geometry, it does not differentiate between any materials or
sub-objects that make up the surface. Specifically for dental
applications, the 3D model does not differentiate between teeth and
gingival, some of which inadvertently will be included in a teeth
scan. For visualization and CAD design of dental restorations, it
can therefore be advantageous to segment the combined 3D model into
teeth and tissue, respectively. Segmentation can be applied by
means of an algorithm implemented in software, yielding model 101.
A segmented teeth model is shown in FIG. 6.
[0146] In one embodiment of the invention, the segmentation
algorithm uses vectors perpendicular to each tooth, or a single
vector, perpendicular to the whole model, and one point in the
middle of each tooth or two points on the distal and mesial sides
of the tooth.
[0147] A preferred version of the separation algorithm is based on
using a 3D shortest path algorithm, preferably capable of handling
negative weights, for example the Bellman-Ford algorithm. The
algorithm is preferably applied on a 3D matrix with elements
representing curvature of the surface of the tooth model 100.
[0148] In another embodiment, the scanner used to generate model
100 can capture color as well. Segmentation can then be based on
color information.
[0149] If step 2 is skipped, models 100 and 101 are identical.
[0150] Step 3: Obtain 3D digital model(s) of face/head (optional in
V1, required in V2):
[0151] There are several systems available for obtaining 3D digital
models of the head, particularly the face (e.g., Konica Minolta
Vivid, Breuckmann faceScan). Head/face and dental scanners are
generally different instruments, because the required resolution
for head/face scans is generally lower, while the volume of
interest is larger. Most optical head/face scanners employ
structured light.
[0152] In a preferred embodiment of this invention, the head/face
scanner can detect not just surface geometry, but also color. Color
(also termed texture) information is important in visualization.
Color can be detected directly by choosing a color-sensitive sensor
in the scanner's camera(s). Another approach is to use a sensor
sensitive to total light intensity only, but take several images
where the illumination is a single base color in each, and then
reconstruct the color by combining those images. This process is
also called stacking of color channels, and typical base colors are
red, green, and blue.
[0153] It is preferable to scan the head/face with the patient
exposing his or her teeth. This constellation can be exploited in
step 6. Generally, the patient will want to smile, because the
aesthetic appearance of a dental restoration is often viewed most
critical for a smile.
[0154] A 3D model of the head may require several scans from
different angles. Multiple such scans have to be aligned to a
combined model. Many algorithms exist for this purpose, for example
Iterative Closest Point. They all require some overlap of at least
pairs of sub-scans. As lighting in every sub-scan generally will
differ, the sub-textures need to be color-adjusted for the combined
texture. For example, texture weaving can be employed to smooth
color differences between different sub-scans [4].
[0155] Due to limited reflectivity, the hair portion of the head is
generally difficult to capture with optical scanners. This
limitation can be overcome by powdering the hair with a reflective
powder. Another method to reconstruct the hair portion in 3D is to
extrude the silhouettes in multiple head images (taken from
different angles) and then to intersect them to form the visual
hull approximation.
[0156] Subsequent to step 3, the flow charts splits into two
branches. These branches are not alternatives, but can both be
executed. They start with steps 4a and 4b, respectively.
[0157] Step 4a: Derive jaw motion (optional in V1, optional in
V2):
[0158] Especially for crown design, it can be advantageous to
account for dynamic occlusal interferences. With a plurality of
face scan models 200, it is possible to deduct the articulation of
the jaw and thus simulate dynamic occlusal interferences given a 3D
model of the teeth 101 that includes the antagonist. To deduct the
articulation from 3D facial models, it may be advantageous to fix
one or more reference sphere(s) to the patient's mandibular teeth,
preferably between the lower lip and the mandibular incisors, and
to track that sphere's motion. The procedure is described for a
single sphere and 2D images in [9], but can be expected to be more
precise with 3D data, and to correctly detect rotational movements
if more than one sphere is used. Additional sphere(s) or object(s)
can also be fixed on the patient's maxillary teeth. With 3D data,
any concurrent movement of the head can be separated from movement
of the jaw during chewing. WO 2009/091439 discloses a procedure
where 3D movements are deducted by tracking dental objects. This is
however much less accurate than using reference sphere(s), because
spheres, unlike dental objects, have a perfect geometric surface
from which it is possible to determine a center position with high
precision and accuracy. Accordingly, many metrological standards
employ reference spheres, e.g. ISO 10360-3.
[0159] Step 4b: Remove teeth (optional in V1, optional in V2):
[0160] If any face/head model 200 shows the teeth (and possibly the
gingival scaffold), it can be advantageous to cut them out, and to
later (e.g. in step 6) display the teeth/gingiva model 101 (V1) or
401 (V2) in their place. The latter model will often have a higher
degree of detail, as a high level of detail is required for
modeling the dental restoration in step 6. The cutting could also
apply to only some of the teeth, for example if the model 101 or
401, resp., only has some teeth, or even a single tooth. Said
cutting is performed in software, where it can be performed
interactively or at least partially automated.
[0161] Interactive cutting can for example be performed in 3D
software by placing a 3D line on the model, cutting out all points
and/or facets inside the line. Possibly, facets can be sub-divided
along the cutting line, such that the cutting line is respected
precisely. One way of entering the cutting line in the 3D software
is to click on some reference points, and use a spline to connect
them. The spline should follow the surface of model 200. Automated
cutting can be performed by detecting teeth (and possibly gingiva)
by software algorithms. For example, teeth can be detected as such
by their color and/or their shape.
[0162] If model 101 or 401, resp., includes a complete set of
teeth, the inner commissure is the preferred section in model 200
to cut out, as delineated by the innermost confluences of the
vermillion of the lips at the corners of the mouth [1].
[0163] Step 5: Align teeth model to face scan (optional in V1, not
applicable in V2):
[0164] In this step, the teeth/gingiva model 101 is aligned with
some head/face model 200, or--if step 4 was performed--the cut head
face model 201. In other words, the position of model 101 becomes
that of the corresponding portion of model 200/201, and both can be
displayed simultaneously in a meaningful way. Alignment is thus a
rigid transformation of at least one model, either into the local
coordinate system of the other, or into some other common
coordinate system.
[0165] The alignment is preferably performed in software,
interactively and/or automatically. Interactive alignment can be
performed in the graphical user interface provided by the software
by dragging a model (translation), or dragging some control points
for rotations. Another way to transform a model is to enter or
adjust the transformation matrix directly.
[0166] The criterion for alignment can be a subjective visual fit
or be defined mathematically. A common such criterion is the sum of
squared distances between the two models. Distances are usually
measured in the direction of the surface normals. Other criteria
could be based on the distances between certain features, such as
the incisal planes, or the midline(s) between incisors.
[0167] Automatic alignment can be performed using the same
algorithms as in step 3. Possibly, the user will have to place
control points for corresponding points of the models to be
aligned, those serving as a first guess for the automated fine
alignment. Automated alignment is an optimization of the
mathematically defined fit criterion. In case the head/face model
200 does not expose the teeth on the surface, alignment with the
teeth/gingiva model 101, alignment can still be possible if the
head/face model is a cephalogram (x-rays of the head) [5].
[0168] Step 6: Design restoration in CAD system (required in V1,
required in V2):
[0169] This step is largely identical in both variants (i.e. V1 and
V2), but starts from the pre-prepared teeth in variant V1, while in
variant V2, it starts from the prepared teeth. The earlier position
in the work flow in variant V1 allows some additional possibilities
in this variant.
[0170] Common features in step 6 in both variants V1 and V2:
[0171] Dental restorations that can be designed in a CAD system
include inlays, onlays, veneers, crowns, bridges, combinations
thereof, and others. By analogy, the term "restoration" also covers
removable partial denture frameworks and implant-retained
structures. Several dental CAD software packages that allow such
design are available, for example 3Shape DentalDesigner. Model 300
is that of the restoration only. In this step 6, it is only a
digital model. Its contour in FIG. 4 is C300. The restoration
implies requirements for the preparation. As model 300 is digital,
the preparation is also virtual in this step 6. For a given
restoration model 300, there can be many possible virtual
preparations C102, however some may be more advisable than others
(see step 7). An example contour of a virtual preparation in FIG. 4
is C102. Mainly, C102 is offset from C300 by the cement space. Note
that the thickness of the cement space in FIG. 4 is exaggerated for
graphical clarity only.
[0172] The software used in this step 6 should preferably assist
the dentist/dental technician in designing the restoration, for
example by making automatic suggestions and/or evaluating basic
rules and requirement.
[0173] Basic rules and requirements, preferably implemented in the
software, may include the minimum thickness for the restoration
(generally dependent on material) and biologic width. Other rules
could ascertain the mandatory continuous circumferential height of
a preparation for a crown. The strength of a restoration could be
determined numerically, for example by measuring the thickness or
preferably a finite-element simulation. Yet another rule could be
to not to penetrate the antagonist and proximal teeth.
[0174] In the common case of the head model 101 not being a
volumetric one, it can be advantageous to integrate x-ray images in
this step 6, because the extent of decay visible in these will
constrain the choice of restoration. If multiple x-ray images are
taken from different angles, it will be possible to create an
approximate 3D model from the silhouettes in all images,
analogously to how the hair can be reconstructed in 3D in step 3.
The resolution in 3D of this model will however generally be poor,
because only few X-rays can be taken. Because of this poor quality,
said integration of x-ray images in step 6 may not be a proper
alignment to the other models, but at least a concurrent
visualization in the software. Possibly, the software can detect
the image planes of the x-rays in the 3D model of the teeth (101 in
variant V1, 401 in variant V2) by a best fit between their
sections, and then automatically set the view port in the 3D
visualization of the latter models to match the image planes of the
x-rays.
[0175] A major advantage of this invention is that it enables a
dialog between the patient and the dentist regarding the treatment,
optionally involving the lab also. For example, the dentist can
visualize the proposed restoration on a computer screen.
Preferably, the CAD software that the dental technician/dentist
uses for the virtual design of the restoration itself provides such
visualization and can be used interactively to update the design in
dialog with the patient. The technician/dentist could propose
visual appearance and aesthetic as well as explain functional
advantages and disadvantages of potential restorations, along with
cost. A physical diagnostic wax-up could also be manufactured by
CAM, still more cheaply and quickly than traditional diagnostic
wax-ups.
[0176] It is advantageous to be able to render the available 3D
models photo-realistically. Graphics functionality on PCs, like
OpenGL, aids towards this goal. Proper, or even adjustable,
coloring of gingiva and teeth, respectively, or regions thereof, in
teeth/gingival models (101 in variant V1, 401 in variant V2) is
likewise advantageous. Even if said models were obtained with a
color-enabled scanner, the lighting used to capture it is generally
different from that applied when capturing model 200, leading to a
visual mismatch in the display of all models aligned (step 5).
Special computer graphical techniques, like ray tracing, can
improve the visual appearance, along with the modeling of more than
one light source.
[0177] When a face/head model 201 is available, biometric
information can be exploited for optimizing the aesthetic
impression of the dental restoration [6]. For example, it often
appears ideal to align the facial midline with the arch midline, or
to achieve parallelism between the incisal plane and the
interpupillary line. Metrics for of smile anatomy include the
degree of maxillary anterior tooth display (Morley ratio), upper
lip drape, and gingival display [1].
[0178] If the dental restoration deviates significantly from the
existing conditions, it may have effect on the soft tissue near the
mouth. 3D facial soft-tissue-change prediction after simulated
orthognathic surgical planning has been presented in the literature
[e.g., 7], and an analogous procedure could be applied in the
context of this invention. The outcome of any (optional)
soft-tissue change simulation could be visualized as model 202.
[0179] If step 4a has been performed and a trajectory of the
mandibular teeth has been determined, dynamic occlusal
interferences can be tested in the present invention, allowing the
dentist/dental technician to modify model 300 in order to avoid
such interferences. This procedure may be at least partially
automated removing any parts of model 300 that collide with the
antagonist given said trajectory.
[0180] When the CAD design is finished, a physical diagnostic
wax-up model of the digital model 300, or parts thereof, can be
manufactured by CAM. Such manufacturing requires essentially no
manual labor and is much less expensive than traditional manual
production. The physical wax-up gives the dentist and/or patient
another opportunity of evaluating the proposed treatment before it
is executed. This may be a relevant procedure especially when the
restoration design is performed in a dental lab at another location
or the dentist is very traditional. If a physical diagnostic wax-up
is created, the lab technician may be required to grind on the
pre-preparation model before scanning. In case no physical model
exists one can be manufactured by CAM.
[0181] In another embodiment of the invention the CAD design can
used to create "snap on"s, which can mounted directly on the
patient teeth visualizing the treatment result. The "snap on"s are
directly created by subtracting the pre-prepared teeth from the
design. I.e. the 3D model of the pre-prepared teeth is subtracted
from the CAD model of the designed "snap-on." The resulting
subtracted design provides the a model of the snap-on's that
subsequently can be manufactured by CAM whereupon the snap-on's are
ready-to-use.
[0182] Communication networks provide other means of establishing
interactivity with patient and/or dentist in a situation where the
restoration design is performed in another location. For example,
the patient and/or dentist could follow the design process via a
life internet connection to the designer's computer.
[0183] Variant V1 only: In one embodiment of this invention, the
dentist or dental technician demarcates the desired margin for the
restorative design on the teeth model 101 in the software. In
another embodiment, the dentist chooses a desired surface of the
restoration, e.g., from a crown library (potentially but not
necessarily the same as in the corresponding parts in model 101),
and the software calculates a margin line. Any combination of said
embodiments is also possible, particularly for bridges. Possible
automatic suggestions in the software include margin placement,
particularly apical placement dependent on tooth number. The
dentist may also be offered a selection among a library of standard
restorations, which then can be modified.
[0184] In this step 6, but also with relevance for the preparation
(step 7 below), also temporary crowns can be designed. The
temporary crown will be directly derived from the full CAD design
in step 6, but with additional cement space e.g. 0.2 mm between the
virtual preparation and the inside of the temporary crown. The
increased cement space is created to accommodate for inaccuracies
in the actual preparation performed by the dentist.
[0185] Step 7: Generate preparation guide (optional in V1, not
applicable in V2):
[0186] In a preferred embodiment of the invention the software
assists the dentist with the preparative work. In many cases,
general preparation guides are provided by manufacturers of dental
material and equipment. To ease the dentist's work and to improve
the restorative strength and overall quality, the invention may
provide the preparation guides automatically for the particular
design obtained at the end of step 6.
[0187] Possibly, the software can assist with planning crown
lengthening. In this context, step 2 can be beneficial, preventing
the margin from being placed too sub-gingivally. Also the type of
margin (bevel, shoulder) could be suggested by the software.
[0188] Besides proposing details of the preparation, the software
that generates a preparation guide can possibly also validate a
preparation that the dentist and/or dental technician have devised
by other means. For example, the software can evaluate restorative
strength and/or choice of materials, and/or even the choice of
restorative treatment method.
[0189] The preparation guide can take many forms including
instruction text, multiple 2D screen shoots, 3D animations,
computer visualization, videos and/or instructions for
machined/robot preparation. A preparation guide may also include a
physical model of the desired, positive, preparation, or a physical
negative representation which can be tested in the mouth of the
patient. For example in the case where model 100 is a scanned cast
model, the dental technician could prepare this cast. Because the
virtual preparation is also available in digital form (the dental
preparation CAD model, contour C102 in FIG. 4), it could also be
manufactured by CAM.
[0190] Step 8: Prepare teeth (required in V1, required in V2):
[0191] Based on the agreed restorative treatment and with or
without any guide from step 7, the dentist prepares the patient's
teeth. The preparation is typically performed by the dentist
grinding down the teeth such that the restorative work can be glued
on. In variant V1, the preparation will be for the restoration
designed in step 6, whereas in variant V2, no prior design
determines the preparation work.
[0192] Snap-ons (a commercial product by Snap-on Smile) require no
invasive preparation.
[0193] Step 9: Obtain 3D digital model of prepared teeth and
gingiva (required in V1, required in V2):
[0194] In terms of procedure, this scanning step is identical to
step 1, however in this step, the prepared teeth are scanned. The
contour of the actual preparation in FIG. 4 is C400. For the sake
of simplicity in the figure, it is identical with that of the
virtual preparation C102, but this need not be the case.
[0195] Step 10: Segment prepared teeth from gingiva (optional in
V1, optional in V2):
[0196] The segmentation of teeth and gingival in the prepared model
can be executed analogously to step 2, but applied to the prepared
model instead of the pre-prepared model. If this step is skipped,
models 400 and 401 are identical.
[0197] Step 11: Align (required in V1, required in V2):
[0198] Logically and procedurally, this step is similar in variants
V1 and V2; however this step relates to different models in either
variant.
[0199] Variant V1: Alignment of restoration designed for the
pre-prepared teeth (step 6, model 101), prepared teeth (model 401)
can be performed by the same software algorithms as described in
step 3. Again, it is important to have some overlap in the models.
Such areas will generally exist unless the preparation affects all
teeth. The model of the restoration 300 is already in the same
local coordinate system as model 101, based on which it was
designed. Therefore, model 300 is also aligned with model 401
without any further processing. If the head/face scan (model 201)
is available, it can be aligned to models 101/300 and 401 such that
all three models match. FIG. 7 shows a typical result of this step
11 for such constellation.
[0200] Variant V2: Alignment of prepared teeth (model 401) and the
head/face scan (model 201) can be performed by the same software
algorithms as described in step 3.
[0201] Step 12: Transfer CAD design from pre-prepared to prepared
teeth (required in V1, not applicable in V2):
[0202] Due to the manual preparation the actual preparation C402
(FIG. 5) will in general differ, at least slightly, from the
virtual preparation C102 created in the design step 6. Thus, the
restoration design needs to be modified accordingly, but preferably
the transfer should maintain as much of the design created in step
6 as possible. This procedure is preferably implemented in
software.
[0203] The automation provided by this step 12 is what lacks in the
manual and subjective process that is the current state of
technology. Typically today, to transfer the design, the dental
technician looks at the original diagnostic wax-up and manually
tries to replicate this design for the real restorations,
incorporating potential comments from the dentist and the patient.
This manual replication process is both costly, inaccurate, and
time consuming.
[0204] A preferred algorithm for this step 12 starts by demarcating
the margin line in both the virtual preparation (600 in FIG. 5) and
the actual preparation (601 in FIG. 5). While the margins are
points in the 2D cross section that is FIG. 5, in reality they are
curves in 3D, and can for example be represented by (B-)splines.
Dental CAD software like 3Shape's DentalDesigner can automatically
detect margin lines and place said splines, but user interaction
should also be allowed. The transformation between 600 and 601 is
denoted T.
[0205] A free form deformation (FFD) model can used to generalize T
to surfaces. This process is often also called "morphing". The
morphing operation affects the near-margin portion of model 300,
with decreasing impact for surface portions with decreasing
distances from the margin. The relevant parameters of the algorithm
can be adjusted by the user. A similar procedure for "crown
matching" has been proposed in [8], however outside the scope of
dental restorations. Colloquially speaking, morphing is like
stretching a rubber balloon by pulling or pushing its "lips" (the
thick ring through which the air is blown in, which corresponds to
the margin line).
[0206] Note that in the example shown in FIG. 5, the prepared
margin is located gingivally from the virtual one, so therefore the
exterior surface of model 300 needs to be extended to arrive at
model 301. The opposite case is however also possible. If the
preparation ends up removing less material than assumed when
creating model 300, the exterior surface of model 301 can be
smaller than that of model 300. In other words, morphing can both
be a contraction and a stretching operation. For a given tooth,
morphing can even be a combination of contraction and stretching
along various sections of the margin, namely when there are
deviations between the virtual and actual preparation in both the
gingival and the occusal/incisal direction.
[0207] Away from the margin towards the interior portions of the
preparation/restoration, morphing need not be applied. Instead, the
inner surface of the restoration can be computed in the normal
fashion, i.e., the surface is created by an offset of the
preparation above the margin line controlled by several
parameters.
[0208] Away from the margin along the exterior of the restoration
and beyond the radius of influence of the morphing operation
(section 600 to 602 in FIG. 5), the surfaces of pre-prepared design
and final design are identical, i.e. contours C300 and C301 overlay
each other.
[0209] By combining the identical, the morphed, and the
preparation-generated surface the final CAD design 301 (contour
C301) is completed. When creating the final CAD design, material
and manufacturing process requirements should be included, e.g. the
actual design can be split into two files for pressing. If step 7
was skipped and thus model 102 is not truly available (it is the
same as model 101), the virtual margin line can also be taking from
the model of the restoration 300.
[0210] Further modifications to the design of the restoration can
be made with the same procedures as mentioned under step 6. If
color was adjusted in step 6, it may be advantageous to transfer
the color information to the design and later manufacture of the
restoration.
[0211] Only in the unlikely event of the actual preparation
matching the virtual one, and no other modifications being
desirable, will models 300 and 301 be identical.
[0212] Step 13: Produce (optional in V1, optional in V2):
[0213] Once model 301 has been finalized, it can be produced using
CAM (Computer Aided Manufacturing). Both rapid prototyping (RP)
machines and milling machines can be used for the actual
production. A CAM software (e.g. 3Shape CAMbridge) prepares the
data (including model 301) for production. For RP machines this
preparation typically involves 3D rotation, placement (nesting),
supports, slicing, ID-tags, etc. For milling machines the
preparation typically involves 3D rotation, placement (nesting),
sprues (connector pins), drops, engraving, milling path generation
and post processing, etc. Some dental CAD/CAM solutions include the
same internal steps of preparation for production and are thus
technically suitable for the method described in this invention,
but are currently not open to 3D models generated by other
manufacturers' equipment (e.g., Sirona CEREC).
[0214] The production process can either manufacture the
restoration immediately (e.g., from blocks of zirconia), or
indirectly. In the indirect process, for example wax is milled or
printed and then cast using traditional "lost wax" techniques. Many
manufacturers offer RP (SLA, SLS, SLM, DLP, FDM, Polyjet, etc.)
and/or milling machines suitable for such work, e.g., Roland,
3DSystems, EnvisionTec, Solidscape, DWS, EOS, ProMetal, and
others.
[0215] Manufacturing may in many cases be performed at another
location than the preceding steps. Digital models and designs can
for example be transferred to a processing center via the
internet.
[0216] Although some embodiments have been described and shown in
detail, the invention is not restricted to them, but may also be
embodied in other ways within the scope of the subject matter
defined in the following claims. In particular, it is to be
understood that other embodiments may be utilised and structural
and functional modifications may be made without departing from the
scope of the present invention.
[0217] In device claims enumerating several means, several of these
means can be embodied by one and the same item of hardware. The
mere fact that certain measures are recited in mutually different
dependent claims or described in different embodiments does not
indicate that a combination of these measures cannot be used to
advantage.
[0218] It should be emphasized that the term "comprises/comprising"
when used in this specification is taken to specify the presence of
stated features, integers, steps or components but does not
preclude the presence or addition of one or more other features,
integers, steps, components or groups thereof.
[0219] The features of the method described above and in the
following may be implemented in software and carried out on a data
processing system or other processing means caused by the execution
of computer-executable instructions. The instructions may be
program code means loaded in a memory, such as a RAM, from a
storage medium or from another computer via a computer network.
Alternatively, the described features may be implemented by
hardwired circuitry instead of software or in combination with
software.
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Embodiments
[0229] 1. A method for planning, visualizing, and/or optimizing
dental restoration on at least a part of the pre-prepared teeth of
a patient, wherein said method comprises the steps of: [0230]
providing at least one 3D digital model of at least a part of the
pre-prepared teeth; [0231] designing at least one dental
restoration CAD model based on the 3D digital model of at least a
part of the pre-prepared teeth; [0232] providing at least one 3D
digital model of at least a part of the prepared teeth, where the
prepared teeth are provided by preparing the pre-prepared teeth by
dental restorative work, at least partly based on the dental
restoration CAD model; and [0233] aligning the 3D models of the
pre-prepared and the prepared teeth.
[0234] 2. A method according to embodiment 1, further comprising
the step of designing a dental preparation CAD model, at least
partly based on the model of the pre-prepared teeth.
[0235] 3. A method according to any of the preceding embodiments,
further comprising transferring the design of the dental
restoration CAD model to the model of the prepared teeth.
[0236] 4. A method according to any of the preceding embodiments,
further comprising the step of providing a facial 3D digital model
of the patient, with at least a part of the teeth being visible
and/or exposed, provided by means of optically scanning at least a
part of the face of the patient.
[0237] 5. A method according to embodiment 4, further comprising
the step of at least partly aligning the 3D model of the
pre-prepared teeth and/or the dental restoration CAD model with the
visible teeth in the facial 3D model.
[0238] 6. A method according to any of embodiments 4 to 5, wherein
the dental restoration CAD model is at least partly designed based
on the facial 3D model.
[0239] 7. A method according to any of the embodiments 1 to 6,
further comprising the step of providing a preparation guide for
the dentist prior to preparing the teeth, said preparation guide at
least partly based on the dental preparation CAD model.
[0240] 8. A method according to embodiment 7, wherein said
preparation guide provides assistance in relation to lengthening of
crown(s), location and/or type of the margin, and/or the like, and
wherein the generation of said preparation guide is at least partly
based on the dental restoration CAD model and/or the 3D model of
the pre-prepared teeth and/or the dental preparation CAD model
and/or segmentation of said models.
[0241] 9. A method according to any of embodiments 7 to 8, wherein
said preparation guide comprises instructions for execution of a
machine generated preparation and/or preparation model.
[0242] 10. A method according to any of embodiments 7 to 9, wherein
said preparation guide comprises instruction text, multiple 2D
screen shoots, 3D animations, computer visualization, videos and/or
instructions for machined/robot preparation.
[0243] 11. A method according to any of embodiments 7 to 10,
wherein said preparation guide comprises a dental model of the
preparation, such as a gypsum model and/or a wax-up model, such as
a marked-up dental model.
[0244] 12. A method according to any of the embodiments 5-11,
wherein the preparation guide includes a physical model of the
desired preparation or a negative representation of the desired
preparation which can be tested in the mouth of the patient.
[0245] 13. A method according to any of embodiments 1 to 11,
wherein the step of transferring the design of the dental
restoration CAD model comprises aligning the dental preparation CAD
model with the 3D model of the prepared teeth.
[0246] 14. A method according to embodiments 13, wherein aligning
is at least partly based on detecting and/or demarcating and/or
aligning margin lines of the models.
[0247] 15. A method according to any of embodiments 1 to 14,
wherein the step of transferring the design of the dental
restoration CAD model comprises morphing part of the dental
restoration CAD model to the 3D model of the prepared teeth.
[0248] 16. A method according to embodiment 15, wherein morphing is
applied near the margin line of the dental restoration CAD model
and/or the 3D model of the prepared teeth.
[0249] 17. A method according to any of embodiments 15 to 16,
wherein the impact of morphing is highest near the margin line of
the dental restoration CAD model and/or the 3D model of the
prepared teeth, with decreasing impact of the morphing when
increasing the distance to the margin line.
[0250] 18. A method according to any of embodiments 1 to 17,
wherein the step of transferring the design of the dental
restoration CAD model comprises creating an inner surface of the
dental restoration CAD model as an offset to the 3D model of the
prepared teeth, said offset starting from the margin line of the 3D
model of the prepared teeth in the occlusal/incisal direction.
[0251] 19. A method according to embodiment 18, wherein said offset
is provided automatically.
[0252] 20. A method according to any of embodiments 1 to 19,
wherein a significant part of the outer surface of the dental
restoration CAD model is maintained when transferred to the 3D
model of the prepared teeth, the contour of the inner surface of
the dental restoration CAD model is substantially similar to the
outer surface of the 3D model of the prepared teeth and the margin
line area of the dental restoration CAD model and the 3D model of
the prepared teeth are morphed together.
[0253] 21. A method according to any of embodiments 1 to 20,
wherein the step of transferring the design of the dental
restoration CAD model comprises morphing the dental preparation CAD
model with the 3D model of the prepared teeth, thereby providing a
transformation of the dental preparation CAD model to the 3D model
of the prepared teeth, and subsequently applying this
transformation to the dental restoration CAD model.
[0254] 22. A method according to any of embodiments 1 to 21,
further comprising the step of modifying the design of the dental
restoration CAD model subsequent to the step of transferring said
dental restoration CAD model to the 3D model of the prepared
teeth.
[0255] 23. A method for planning, visualizing, and/or optimizing
dental restorative work on at least a part of the teeth of a
patient, said method comprising the steps of: [0256] providing a 3D
digital model of at least a part of the face of the patient, with
at least a part of the patient's teeth being visible and/or
exposed, provided by means of optically scanning at least a part of
the face of the patient, [0257] obtaining at least one 3D digital
model of at least a part of the prepared teeth, where the prepared
teeth are prepared by dental restorative work, [0258] aligning the
3D model of the prepared teeth with the visible teeth in the 3D
facial model, and [0259] designing at least one dental restoration
CAD model based on the 3D model of the prepared teeth and at least
partly based on the 3D facial model.
[0260] 24. A method according to any of the preceding embodiments,
wherein the 3D model of the pre-prepared and/or the 3D model of the
prepared teeth are provided by means of scanning, such as scanning
intra orally, scanning an impression of the teeth and/or the
antagonist, scanning a cast of the teeth and/or the antagonist, CT
scanning and/or the like scanning methods.
[0261] 25. A method according to any of the preceding embodiments,
further comprising the step of calculating margin lines of the 3D
models.
[0262] 26. A method according to any of the preceding embodiments,
wherein the 3D facial model of the face, the 3D model of the
pre-prepared teeth and/or 3D model of the prepared teeth and/or the
dental restoration CAD model and/or the dental preparation CAD
model comprises information of geometry and texture (color).
[0263] 27.A method according to embodiment 26,wherein color is
detected by means of at least one color sensitive sensor and/or by
means of stacking of color channels.
[0264] 28. A method according to any of the embodiments 4 to 27,
wherein the 3D facial model is provided by means of aligning and/or
combining multiple sub-scans of the face, sub-scans provided from
different angles.
[0265] 29. A method according to embodiment 28, wherein at least
part of the sub-scans are at least partially overlapping.
[0266] 30. A method according to any of the embodiments 28 to 29,
wherein at least a part of the sub-textures of at least a part of
the sub-scans are color adjusted and/or color interpolated, such as
by texture weaving, to provide the texture of the 3D facial
model.
[0267] 31. A method according to any of embodiments 4 to 30,
wherein at least part of the hair of the patient is powdered with a
reflective powder.
[0268] 32. A method according to any of embodiments 28 to 31,
wherein silhouettes from multiple sub-scans are extruded and
subsequently intersected to provide a visual hull
approximation.
[0269] 33. A method according to any of the embodiments 4 to 32,
further comprising the step of cutting and/or removing at least a
part of the teeth from the 3D facial model.
[0270] 34. A method according to any of the embodiments 4 to 33,
wherein design of the dental restoration CAD model is at least
partly based on biometric information for optimizing the aesthetic
impression of the dental restoration, biometric information such as
degree of maxillary anterior tooth display (Morley ratio), upper
lip drape and gingival display.
[0271] 35. A method according to embodiment 34, wherein the facial
midline is substantially aligned with the arch midline, and/or the
incisal plane and the interpupillary line are provided
substantially parallel.
[0272] 36. A method according to any of the preceding embodiments,
wherein the face scanner is used to measure features of the face of
the patient, such as the facial midline, the arch midline, the
incisal plane, and/or the interpupillary line.
[0273] 37. A method according to any of the preceding embodiments,
further comprising the step of providing a least one X-ray image of
at least a part of the head, the jaw, the pre-prepared and/or the
prepared teeth.
[0274] 38. A method according to embodiment 37, wherein multiple
X-ray images obtained from different angles are combined to provide
a 3D X-ray model.
[0275] 39. A method according to embodiment 38, wherein the 3D
X-ray model is aligned with and/or visualized along one or more of
the 3D models and/or the CAD models.
[0276] 40. A method according to any of the preceding embodiments,
wherein automatic and/or semi-automatic assistance is provided in
the design of the dental restoration CAD model and/or the dental
preparation CAD model, assistance such as automatic suggestions,
evaluation of basic rules and requirements and/or the like,
requirements such as medical and/or biologic requirements.
[0277] 41. A method according to any of the preceding embodiments,
wherein a library of standard restorations and/or standard
preparations is provided when designing the dental restoration CAD
model and/or the dental preparation CAD model, a library such as a
library of CAD models.
[0278] 42. A method according to any of the preceding embodiments,
further comprising the step of estimating the strength of a planned
dental restoration, such as estimating by means of finite-element
simulation.
[0279] 43. A method according to any of the preceding embodiments,
further comprising the step of visualizing the dental restoration
CAD model, for example for the patient, dentist and/or dental
technician.
[0280] 44. A method according to any of the preceding embodiments,
wherein the dental restoration CAD model is visualized
side-by-side, along and/or on top of the model of the pre-prepared
teeth
[0281] 45. A method according to any embodiments 4 to 43, further
comprising the step of visualizing the dental restoration CAD model
aligned in the facial model.
[0282] 46. A method according to any of the preceding embodiments,
further comprising the step of predicting and/or visualizing the
facial soft-tissue-change occurring as a result of the dental
restorative work.
[0283] 47. A method according to any of the preceding embodiments,
wherein visualization is provided in 3D, such as visualization of
3D models and CAD models.
[0284] 48. A method according to any of the preceding embodiments,
wherein visualization is provided by means of at least one computer
screen and/or by means of manufacturing of at least one diagnostic
wax-up.
[0285] 49. A method according to any of the preceding embodiments,
wherein visualization is provided over a computer network, such as
the internet.
[0286] 50. A method according to any of the preceding embodiments,
further comprising the step of predicting and/or visualizing the
facial soft-tissue-change occurring as a result of the dental
restorative work.
[0287] 51. A method according to any of the preceding embodiments,
further comprising the step of at least partially segmenting teeth
and tissue, such as gingival, in the 3D model of the pre-prepared
teeth and/or in the 3D model of the prepared teeth and/or in the 3D
facial model.
[0288] 52. A method according to embodiment 51, wherein
segmentation is at least partly provided by means of a computer
implemented algorithm, such as a shortest-path algorithm applied on
a 3D matrix representing curvature of the tooth surface.
[0289] 53. A method according to any of embodiments 51 to 52,
wherein segmentation is at least partly based on color information
in the 3D model(s).
[0290] 54. A method for planning, visualizing, and/or optimizing
dental restoration on at least a part of the pre-prepared teeth of
a patient, where said method comprises the steps of: [0291]
providing at least one 3D digital model of at least a part of the
pre-prepared teeth; [0292] designing at least one dental
restoration CAD model based on the 3D digital model of at least a
part of the pre-prepared teeth; [0293] where the method further
comprises the step of: [0294] simulating and estimating dynamic
occlusal interferences, and [0295] wherein said interferences are
deduced at least partly from a plurality of scans that record said
patient's jaw articulation by tracking at least one reference
object fixed to the patient's teeth.
[0296] 55. A method according to any of the preceding embodiments,
wherein the face scanner is used to measure 3D movements of the
jaws and face of the patient in real time.
[0297] 56. A method according to any of the preceding embodiments,
wherein the face scanner is used to measure the position of the
upper jaw and/or lower jaw with respect to the skull.
[0298] 57. A method according to any of the preceding embodiments,
further comprising the step of interactively modifying and/or
optimizing the design of the dental restoration CAD model, based on
input from a dentist and/or the patient and/or from considerations
relating to aesthetic appearance, biometrics, medial and/or
biological rules and/or requirements, estimation of strength,
soft-tissue change, occlusal interferences, color issues, cost of
restoration and/or the like.
[0299] 58. A method according to embodiment 57, wherein interactive
modification and optimization of the dental restoration CAD model
is provided across a computer network, such as patient, dentist
and/or dental technician being located at different geographic
locations.
[0300] 59. A method according to any of the preceding embodiments,
further comprising the step of evaluating and/or validating a
preparation guide and/or a set of prepared teeth, at least partly
based on a 3D model of said prepared teeth.
[0301] 60. A method according to embodiment 59, wherein evaluation
and/or validation comprises estimating and/or evaluating a proposed
dental restoration, choice of materials, choice of restorative
method, and/or the like.
[0302] 61. A method according to any of the preceding embodiments,
wherein a dental restoration can be one or more inlays, onlays,
veneers, crowns, bridges or combinations thereof and/or a dental
restoration can be a removable partial denture framework and/or an
implant-retained structure.
[0303] 62. A method according to any of the preceding embodiments
further comprising planning, visualization, and/or optimization of
plastic surgery applied to the head and/or face.
[0304] 63. A method according to any of the preceding embodiments
further comprising planning, visualization, and/or optimization of
at least one "snap on", wherein a "snap-on" CAD model is created by
subtracting the 3D model of the pre-prepared teeth from the dental
restoration CAD model.
[0305] 64. A method according to any of the preceding embodiments,
further comprising the step of manufacturing of a dental
restoration for the prepared teeth based on the dental restoration
CAD model, by means of CAM.
[0306] 65. A method according to any of the preceding embodiments,
further comprising the step of manufacturing of a diagnostic wax-up
based on the dental restoration CAD model, by means of CAM.
[0307] 66. A method according to any of the preceding embodiments,
further comprising the step of manufacturing of a preparation guide
for the prepared teeth based on the dental preparation CAD model,
by means of CAM.
[0308] 67. A method according to any of the preceding embodiments,
further comprising the step of manufacturing of a diagnostic wax-up
based on the dental preparation CAD model and/or the preparation
guide, by means of CAM.
[0309] 68. A method according to any of the preceding embodiments,
wherein CAM instructions for manufacturing of the dental
restoration are provided and/or distributed by means of a computer
network, such as transferred to a processing centre via the
internet.
[0310] 69. A method according to any of the preceding embodiments,
wherein any listed step at least partly is provided by means of CAD
or can be provided by means of CAD.
[0311] 70. A method according to any of the preceding embodiments,
further comprising designing a temporary crown, where the temporary
crown is derived from the CAD design.
[0312] 71. A system for planning, visualizing, and/or optimizing
dental restoration on at least a part of the pre-prepared teeth of
a patient, wherein said system comprises: [0313] means for
providing at least one 3D digital model of at least a part of the
pre-prepared teeth; [0314] means for designing at least one dental
restoration CAD model based on the 3D digital model of at least a
part of the pre-prepared teeth; [0315] means for providing at least
one 3D digital model of at least a part of the prepared teeth,
where the prepared teeth are provided by preparing the pre-prepared
teeth by dental restorative work, at least partly based on the
dental restoration CAD model; and [0316] means for aligning the 3D
models of the pre-prepared and the prepared teeth.
[0317] 72. A computer program product having a computer readable
medium, said computer program product providing a system for
planning, visualizing, optimizing and/or executing dental
restoration on at least a part of the teeth, such as the
pre-prepared teeth, of a patient, said computer program product
comprising means for carrying out any of the steps of any of the
methods according to any of embodiments 1 to 70.
[0318] 73. A computer program product comprising program code means
for causing a data processing system to perform the method of any
one of embodiments 1-70, when said program code means are executed
on the data processing system.
[0319] 74. A computer program product according to embodiment 73,
comprising a computer-readable medium having stored there on the
program code means.
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