# Patent

## Title
System and process for duplication of dentures

## Abstract

Systems and processes for the duplication of dentures from existing dentures. The interior and exterior of the dentures are scanned and a best fit procedure is used to create a fully digitized denture. The denture teeth are selected from a library that is the closest fit to the original denture teeth. The library teeth are offset a preset distance to compensate for the best fit. The teeth are then subtracted from the digitized denture. The margins of the denture are then cleaned after subtracting the teeth. The denture base is then ready for manufacturing. The teeth are then installed onto the denture base and provided to the patient.

## Background
FIELD OF THE INVENTION
The present invention relates to the field of denture manufacture and particularly the duplication of existing dentures.
BACKGROUND
Dentures are worn by a considerable number of individuals. The average life span of a denture is approximately seven years, although many individuals continue to wear dentures well beyond that time period. Additionally, dentures become ill-fitting over time due to changes in the patients anatomy. Dentures may also become damaged over time as well. Also, some individuals may want to have a spare denture in case of the loss of the original denture or in the event of an accidental fracture of their primary denture. The cost and time of creating a new denture can often be considerable. Thus, it is often desirable to make a new denture based on an existing denture, particularly if the patient is satisfied with their existing dentures.
The duplication of an existing denture is preferable in most circumstances as the transfer of the shape of the existing dentures maintain the neuromuscular control to the new dentures. Minor modifications are often necessary as well to compensate for worn teeth and denture bases and for changes in the patients anatomy.
There are a number of techniques currently available for providing a patient with a duplicate denture. Many times a temporary denture will be fabricated by the dentist for the patient while the new denture is being fabricated. However, these temporary dentures are usually ill-fitting, uncomfortable and not intended for continued use. Duplicate dentures are normally fabricated based on the prescription and information from the individual's original dentures, if available. Often, there may be a considerable amount of time that has elapsed and such information may not be available. So rather than create a new denture from scratch, it is often more sensible to duplicate a new denture from existing dentures.
There are a number of techniques currently available for duplicating existing dentures. These techniques involve producing a mold by inserting the existing denture into a rigid container such as a duplicating flask, dental flask or other container filled with an elastic material such as alginate or silicon putty. A wax or auto-polymerizing resin template is then fabricated from the mold. This template is tried in the patient's mouth and modifications are made if necessary. Then the final denture is made and provided to the patient. Other variations include forming a wax rim instead of the auto-polymerizing resin or using a silicon putty to create the denture base. These techniques require several try-ins to ensure the proper fit in the patient and the creation of initial templates or wax rims, then the actual denture. This entails considerable time and expense for the patient.
SUMMARY OF THE INVENTION
The present invention provides systems and processes for the precise duplication of dentures from existing dentures. The duplicate dentures can be ready for delivery to the patient in a relatively short time frame. The duplicate denture may even be manufactured in the dentist office.
A preferred embodiment of the present invention provides systems and processes for duplicating a denture from an existing denture. The denture is scanned and the scanned images are used to create a fully digitized denture. A denture base can be fabricated from this model and denture teeth can be designed or selected from a library that is the closest fit to the original denture. The teeth in the digital model are offset a preset distance. The teeth with offset are then subtracted from the digitized denture. The margins of the denture are then cleaned after subtracting the teeth. The denture base is then ready for manufacturing. The teeth are then installed onto the denture base.
In an alternative embodiment of the present invention, the interior and exterior of the dentures can be scanned as discussed above. The dentist can also provide additional information regarding the dentures and the patient as well to ensure a proper fit. This additional information may be used to change the digitized model of the denture.
Another embodiment of the present invention may use the existing dentures to create bite impressions which are scanned along with the existing dentures. These scans are used to create a digital three dimensional image of the denture. This digital model is then used to fabricate a duplicate denture.
The digitized denture model in another preferred embodiment, may also be used to create a denture base. The teeth are subtracted from the model, and teeth are either selected from a library or the teeth may be directly fabricated from the denture information. The denture teeth are temporarily installed in the denture base. This temporary denture is then tried onto the patient. If the fit is not correct, then the denture is used as a secondary impression tray to create a set of bite impressions. These impressions are scanned and used to select or fabricate another denture base. The teeth are installed again and the denture is tried on the patient. This process is repeated until the patient is satisfied. At that point, the teeth are permanently installed, the denture is finally processed and delivered to the patient.
A preferred embodiment of the present invention creates a best fit for the duplicate denture that maintains the occlusal scheme of the existing denture. The occlusal scheme is maintained while allowing changes to the denture for anatomical, functional and aesthetic reasons.
The term anatomical landmarks refers to the structures on the anatomy of the wearer that define the periphery of the denture. Examples of anatomical landmarks include at least one of a vertical height relation to an upper and lower bite alignment, a lip support, a smile line, a centric relationship and a midline measurement.
These and other features of the claimed inventions will be evident from the ensuing detailed description of preferred embodiments, from the drawings and from the claims.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of the work flow process of one preferred embodiment.
FIG. 2 is an illustration of a denture to be duplicated.
FIG. 3 is an illustration of the scanned images of the denture.
FIG. 4 is an illustration of a digital three dimensional model of the denture.
FIG. 5 is another view of the digital model of the denture.
FIG. 6 is an illustration of the digital denture model.
FIG. 7 is an illustration of the model with an offset added to the teeth.
FIG. 8 is an illustration of the digital denture with the teeth being subtracted.
FIG. 9 is an illustration of the digital denture base being cleaned after the teeth has been subtracted.
FIG. 10 is an illustration of the machined denture base.
FIG. 11 is another view of the machined denture base.
FIG. 12 is a view of the duplicated denture.
FIG. 13 is another view of the duplicated denture.



DETAILED DESCRIPTION
The present invention provides systems and process for the duplication of dentures. Descriptive embodiments are provided before for explanatory purposes. It is to be expressly understood that the present invention is not be limited to these descriptive embodiments. Other embodiments are considered to be within the scope of the present invention, including without limitation the use of the present invention for other applications, such as denture duplication, dental implants, and other dental and orthodontic applications. The descriptions below discuss the systems of the present invention as used in dental labs, but it is to be expressly understood that these systems could also be implemented in the dentist office or through a network allowing interaction between the dentist and the dental lab through the systems. The processes and systems of the present invention may also be used in combination with all or parts of the following applications, entitled System and Processes for Optimization for Dentures, Ser. No. 12/939,141; System and Process for Forming Anatomical Features in Dentures, Ser. No. 12/939,138; and Removable Handle for Use with Dentures, Ser. No. 12/939,143 all of which are hereby incorporated herein by reference.
The terms denture base generally refers to the part of a denture that fits the oral mucosa of the basal seat, restores the normal contours of the soft tissues of the edentulous or partly edentures mouth, and supports the artificial teeth. The term denture refers to the denture base with the artificial teeth attached.
Overview
A preferred embodiment of the present invention provides systems and processes for duplicating a denture from an existing denture. The denture is scanned and a best fit procedure is used to create a fully digitized denture. An offset is added to the overall dimension of the denture teeth. The denture teeth with the offset are then subtracted from the digitized denture model. The margins of the denture are then cleaned after subtracting the teeth. The denture base is then ready for manufacturing. The teeth are then installed onto the denture base.
Process
A preferred embodiment of the present invention is disclosed that allows new dentures to be created from an existing denture. The patient provides their existing dentures to the dentist for scanning. Digital scans 30, 32 are created from the inside and outside of the original denture 20 as shown in FIGS. 2 and 3. Once the scans are performed, the denture can be returned to the patient. The system, as shown in the work flow diagram of FIG. 1, applies a series of routines to create a digital three dimensional model 40 of the existing denture as shown in FIGS. 4 and 5.
This digitized denture model 40 is then digitally compared with denture teeth from a library to select the best fitting denture teeth 50 in the scanned model as shown in FIG. 6. The denture teeth 50 are then offset by a preset amount as shown in FIG. 7. This adds an overall thickness to the teeth. The teeth are then digitally subtracted from the digitized denture model as shown in FIG. 8. The offset added to the teeth creates slightly larger pockets in the denture base. The margins are then cleaned after the teeth have been subtracted as shown in FIG. 9. This creates a digital model 60 of the denture base for the patient as shown in FIG. 10.
The denture teeth may be either selected from a library or fabricated from the digital model in a number of process. In this preferred embodiment, the denture base is machined in acrylic based on the digital model 60. This can be done relatively quickly. Once the denture base 70 has been fabricated as shown in FIGS. 10 and 11, the teeth 72 are installed and delivered to the patient for try-in and use as shown in FIGS. 12 and 13.
This entire process can be done in a relatively fast time frame. In some instance, the duplication process can take place in the dentist offices. In other instances, the scanned images of the existing denture can be transmitted to a nearby dental lab where the denture is fabricated and courier to the dentist.
In an alternative embodiment of the present invention, the interior and exterior of the dentures can be scanned as discussed above. The dentist can also provide additional information regarding the dentures and the patient as well. For example, the dentist may notice that the dentures are no longer properly fitting due to wear of the denture base or the teeth or due to changes in the patient's anatomy. This additional information may be used to change the digitized model of the denture.
In yet another alternative embodiment of the present invention, the dentist may provide additional information beyond the scanned images of the interior and exterior of the dentures. The dentist may use those existing dentures as an impression tray to take bite impressions of the patient. Those bite impressions are then scanned and used along with the scanned images of the interior and exterior of the dentures to create the digitized denture.
The occlusal scheme of the existing denture is maintained in the duplicate denture. The duplicate denture can be modified to accommodate anatomical, aesthetic and functional changes that might be necessary.
The digitized denture model 40, in another preferred embodiment, may also be used to create a model for a denture base. The teeth are subtracted from the model, and a denture base is directly fabricated from the denture base information. A denture base is then fabricated, the margins are cleaned and teeth are temporarily installed. This try-in denture is then tried onto the patient. If the fit is not correct, then the denture is used as a secondary impression tray to create a set of bite impressions. These impressions are scanned and used to select or fabricate another denture base. The teeth are installed again and the denture is tried on the patient. This process is repeated until the patient is satisfied. At that point, the teeth are permanently installed, the denture is finally processed and installed to the patient.
A preferred embodiment of the present invention may be implemented in a number of ways.
The above descriptions are intended for explanatory purposes and are not meant to the limit the scope of the claimed inventions. Other embodiments may be covered under the claims as well.

## Claims

1. A computer implemented method for duplicating dentures from an existing denture, the method comprising the steps of:
taking a scan of the existing denture comprising existing teeth and an existing denture base;
creating a digital three dimensional model comprising digital scanned teeth and a digital scanned denture base from the scan of the existing denture, wherein the creating comprises:
fitting digital denture teeth from a library to a digital denture in response to the digital three dimensional model;
offsetting the digital scanned teeth by a predetermined amount to create offset digital denture teeth, wherein the offsetting comprises:
selecting denture teeth that are a closest fit to the existing teeth from among the library;
adding a thickness to the digital scanned teeth in response to the selecting, the thickness comprising the predetermined amount;

subtracting the offset digital denture teeth from the digital scanned denture base to create pockets in the digital scanned denture base, said pockets being larger than the digital denture teeth prior to the step of offsetting the digital scanned teeth;
removing margins from the digital denture;

manufacturing a first denture base from the digital three dimensional model, wherein the manufacturing comprises fabricating pockets in the first denture base corresponding to the offset digital denture teeth in response to the digital three dimensional model; and
installing teeth corresponding to the digital denture teeth to the first denture base.

2. The method of claim 1, wherein the step of removing the margins comprises cleaning digital artifacts from the digital denture.

3. The method of claim 1 wherein the step of taking the scan of the existing denture includes:
taking a scan of the interior of the existing denture; and
taking a scan of the exterior of the existing denture; and
merging the scans together to form one model.

4. The method of claim 1 wherein the method further includes:
providing additional information to correct the fit of the existing denture to improve the fit of the duplicate denture.

5. The method of claim 1 wherein the method further includes:
using the existing denture as an impression tray;
taking bite impressions using the existing denture;
scanning the bite impressions; and
creating a digital model of the existing denture in response to the bite impressions.

6. The method of claim 1 further comprising:
receiving try-in fitting data collected by try-in fitting the first denture base in a patient's mouth;
manufacturing a second denture base based on the digital three dimensional model and the try-in fitting data.

7. The method of claim 4 wherein said method further includes adjusting the digital three dimensional model according to measurements of facial anatomical landmarks of a patient, the anatomical landmarks correlating to the periphery of the existing denture comprising at least one of a vertical height relation to an upper and lower bite alignment, a lip support, a smile line, a centric relationship, and a midline measurement.

8. The method of claim 1 wherein the method further includes adjusting the digital three dimensional model according to measurements of facial anatomical landmarks.

9. A computer implemented method for duplicating dentures from an existing denture comprising the steps of:
receiving patient data comprising a scan of an existing denture comprising existing teeth and an existing denture base;
creating a digital three dimensional model comprising digital scanned teeth and a digital scanned denture base from the patient data,
wherein the creating of the digital three dimensional model comprises:
fitting digital denture teeth from a library to a digital denture base in response to the digital three dimensional model;
offsetting the digital scanned teeth by a predetermined amount to create offset digital denture teeth, wherein the offsetting comprises:
selecting denture teeth that are a closest fit to the existing teeth from among the library;
adding a thickness to the digital scanned teeth in response to the selecting, the thickness comprising the predetermined amount;
subtracting the offset digital denture teeth from the digital scanned denture base to create pockets in the digital scanned denture base, said pockets being larger than the digital denture teeth prior to the step of offsetting the digital scanned teeth

removing margins from the digital denture base


manufacturing a first denture base based on the digital three dimensional model; and
installing teeth corresponding to the digital denture teeth to the first denture base.

10. The method of claim 9 wherein the patient data comprises bite impression data.

11. The method of claim 9 wherein the patient data comprises measurements of facial anatomical landmarks of a patient, the anatomical landmarks correlating to the periphery of the existing denture.

12. The method of claim 9 wherein the patient data comprises:
bite impression data; and
measurements of facial anatomical landmarks.

13. The method of claim 9 further comprising:
receiving try-in fitting data collected by try-in fitting the first denture base in a patient's mouth wherein the first denture base comprises a try-in denture base;
manufacturing a second denture base based on the digital three dimensional model and the try-in fitting data wherein the second denture base comprises a permanent denture base.

14. The method of claim 9 wherein the patient data comprises try-in fitting data.

15. The method of claim 9 wherein the step of installing teeth corresponding to the digital denture teeth to the first denture base comprises: fabricating the teeth corresponding to the digital denture teeth from the library in response to the digital three dimensional model, or fabricating the teeth based on the digital scanned teeth.

16. The method of claim 9 wherein the step of manufacturing the first denture base comprises:
fabricating pockets in the first denture base corresponding to the offset digital denture teeth in response to the digital three dimensional model.

17. The method of claim 1 wherein the step of installing teeth corresponding to the digital denture teeth to the first denture base comprises: fabricating the teeth corresponding to the digital denture teeth from the library in response to the digital three dimensional model, or fabricating the teeth based on the digital scanned teeth.