SYSTEM AND METHOD FOR FABRICATING A DENTAL TRAY

Abstract

According to an embodiment, a method for generating a digital data set for fabricating a physical dental bleaching tray useable to deliver an bleaching agent is disclosed. The method includes obtaining a three-dimensional digital representation of a patient’s dentition including teeth and gingiva; segmenting two or more teeth into individual tooth; identifying a facial surface of at least one of the segmented tooth; defining a facial surface portion including a surface area that is at least partly bound by a virtual boundary that is non- interfacing with the gingiva; generating a modified three-dimensional digital representation using the defined facial surface portion; and generating, based on the modified three-dimensional digital representation, the digital data set configured to be used in fabricating the physical dental bleaching tray.

Claims

1. A method for fabricating a physical dental bleaching tray useable to deliver a bleaching agent, comprising obtaining a three-dimensional digital representation of a patient’s dentition comprising teeth and gingiva; segmenting two or more of the teeth into individual tooth; identifying a facial surface of at least one of the segmented tooth; defining a facial surface portion comprising a surface area that is at least partly bound by a virtual boundary that is non-interfacing with the gingiva; and fabricating the physical dental bleaching tray comprising at least one cavity for receiving the patient’s teeth and at least one receptacle that is generated based on the surface area, wherein the at least one receptacle is configured to receive a bleaching agent.

2. The method according to claim 1, further comprising generating a modified three-dimensional digital representation using the defined facial surface portion; and generating, based on the modified three-dimensional digital representation, a digital data set configured to be used in fabricating the physical dental bleaching tray.

3. The method according to claim 1, further comprising defining the virtual boundary wherein the virtual boundary comprises a first section comprising an offset curve away from an interface between the at least one of the segmented tooth and gingiva, and a second section comprising another offset curve away from tooth edges of the at least one of the segmented tooth, the first section and the second section in combination bound the surface area of the facial surface portion; and/ or the virtual boundary comprises a first section comprising an offset curve away from an interface between each of more than one of at least two of the segmented tooth and gingiva, and a second section comprising another offset curve away from collective tooth edges of the more than one of the at least two of the segmented tooth, the first section and the second section in combination bound the surface area of the facial surface portion.

4. The method according to claim 1, further comprising defining the virtual boundary wherein the virtual boundary comprises a first section defined by an offset curve away from an interface between the at least one of the segmented tooth and gingiva, and a second section comprising at least one tooth edge of the at least one of the segmented tooth, the at least one tooth edge being non-interfacing with the gingiva; and the first section and the second section in combination bound the surface area of the facial surface portion; and/ or the virtual boundary comprises a first section defined at least in part by an offset curve away from an interface between each of more than one of at least two of the segmented tooth and gingiva, and a second section comprising at least one collective teeth edge of the more than one of at least two of the segmented tooth, the at least one collective teeth edge being non-interfacing with the gingiva; and the first section and the second section in combination bound the surface area of the portion.

5. The method according to claim 1, wherein the first section comprises the offset curve that is in immediate vicinity of the interface between the at least one of the segmented tooth and gingiva; and/ or the second section comprising another offset curve away from tooth edges of the at least one of the segmented tooth and/ or collective tooth edges of the more than one of the at least two of the segmented tooth is in immediate vicinity of the tooth edges and/ or collective tooth edges respectively.

6. The method according to claim 2, wherein generating the modified three-dimensional digital representation using the defined facial surface portion comprises increasing height or projected height of at least a part of the facial surface portion.

7. The method according to claim 2, wherein the modified three-dimensional digital representation comprises a modified three-dimensional digital representation of a patient’s dentition, wherein increasing the height comprises scaling up at least a part of the facial surface portion of the three-dimensional digital representation of the patient’s dentition.

8. The method according to claim 2, wherein the modified three-dimensional digital representation comprises a modified three-dimensional digital representation of a patient’s dentition, wherein increasing the height comprises adding a height increasing virtual surface over at least a part of surface area of the facial surface portion of the three-dimensional digital representation of the patient’s dentition.

9. The method according to claim 1, wherein the modified three-dimensional digital representation comprises a modified three-dimensional structure defined by a layer comprising a cavity for receiving patient’s dentition with a receptacle for receiving an bleaching agent, and the method further comprising forming the three-dimensional layer over a modified three-dimensional digital representation of a patient’s dentition having the increased height in at least a part of the surface area of the facial surface portion of the three-dimensional digital representation.

10. The method according to claim 2, wherein the modified three-dimensional digital representation comprises a three-dimensional digital structure defined by a layer comprising a cavity for receiving patient’s dentition with a receptacle for receiving an bleaching agent, and the method further comprising forming the three-dimensional layer over the three-dimensional digital representation of a patient’s dentition to define the cavity; projecting a plurality of vectors from at least a part of surface of the facial surface portion in a direction away from the at least a part of surface to define the projected height, and generating a surface using height points associated with the projected height to define the receptacle.

11. The method according to claim 1, wherein fabricating the physical dental bleaching tray comprises fabricating, using the digital data set, a physical three-dimensional model of the modified three-dimensional digital representation of a patient’s dentition; and thermoforming or vacuum-forming a polymeric sheet material over the physical three-dimensional model to generate the physical dental bleaching tray; or fabricating, using the digital data set, the three-dimensional digital structure using additive manufacturing to generate the physical dental bleaching tray.

12. The method according to claim 1, wherein at least one of the segmenting, identifying the facial surface, defining the virtual boundary, generating the modified three-dimensional digital representation, or generating the three-dimensional digital structure is performed automatically.

13. The method according to claim 1, wherein the virtual boundary, at least in part, is manipulable and comprises a plurality of control points, the method further comprising manually modifying the manipulable virtual boundary using the plurality of control points; and/ or the height or projected height, at least in part, is manipulable and comprises a plurality of control points, the method further comprising manually changing the height or projected height using the plurality of control points.

14. The method according to claim 1, further comprises identifying occlusal surface of the at least one of the segmented tooth; modifying the generated modified three-dimensional digital representation based on the identified occlusal surface, the modification corresponding to a pocket of the physical dental bleaching tray; and fabricating the physical dental bleaching tray to additionally include the pocket.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0074] The embodiments of the disclosure, together with its advantages, may be best understood from the following illustrative and non-limiting detailed description taken in conjunction with the accompanying figures in which

[0075] FIG. 1 shows a three-dimensional digital representation of a patients dentition according to an embodiment;

[0076] FIG. 2 shows the three-dimensional representation of the upper jaw according to an embodiment;

[0077] FIG. 3 shows a modified digital representation of an upper jaw; and

[0078] FIG. 4 shows a bleaching tray according to an embodiment.

DETAILED DESCRIPTION

[0079] In the following description, reference is made to the accompanying figures, which show by way of illustration how the invention may be practiced.

[0080] FIG. 1 shows a three dimensional digital representation of a patients dentition in the form of the upper jaw 1, comprising representations of the patients teeth 2 and gingiva 3 in the upper jaw.

[0081] The three dimensional representation of the upper jaw 1 is based on a digital scan of the upper jaw. The digital scan can be obtained in different ways, the most common are typically either by directly intra oral scanning the upper jaw or by taking a physical impression of the upper jaw and subsequently provide a cast thereof which is scanned or by inverting a scan of the impression tray.

[0082] The digital scan is subsequently processed. Data may be cleaned up and a mesh model is generated that enables the digital scan to be visualized on a monitor.

[0083] Furthermore gingiva and teeth are identified in a segmentation process. As shown in FIG. 1 the segmentation has provide a tooth and gingiva boundary line 4 defining the boundary between the gingiva and the teeth. Interproximal edges 5 are furthermore identified. The interproximal edges identifies the respective mesial and distal edges of a tooth and together with the tooth and gingiva boundary line 4 and the incisal edge 6 of each tooth in the upper jaw can be determined from the scan data. As shown each tooth has been segmented and individual tooth numbering has been provided.

[0084] Thus, the left incisor 8 has been indexed 8, where all the teeth have a respective index number set by the software as shown. The left incisor 8 is defined by a left incisor boundary line 8-1, which forms part of the tooth and gingiva boundary line 4, its incisal edge 8-2 and respective mesial edge 8-3 and distal edge 8-4 defined by the respective two interproximal edges 5.

[0085] In a corresponding manner each tooth 1 - 15, is defined by a boundary line 1-1, 2-1, 3-1, ... 13-1, 14-1, 15-1 which each forms part of the tooth and gingiva boundary line 4, its incisal edge 1-2, 2-2, 3-2, ... 13-2, 14-2, 15-2 its mesial edge 1-3, 2-3, 3-3, ... 13-3, 14-3, 15-3 and its distal edge 1-4, 2-4, 3-4, ... 13-4, 14-4, 15-4, respectively.

[0086] FIG. 2 shows the three dimensional representation of the upper jaw 1 where further analysis has been provided. Using the left incisor 8 as an example of a virtual boundary 8-5 is defined by offsetting boundary line 8-1 of the left incisor 8 along the tooth surface in a direction away from the gingiva.

[0087] Together with the mesial and distal edges 8-3 and 8-4 and the incisal edge 8-2 the virtual boundary 8-5 defines a surface area 8-6 which does not interface or overlap with the gingiva of the upper jaw.

[0088] This process of generating a virtual boundary line and defining a surface area 1-6, 2-6, 3-6, ... 13-6, 14-6, 15-6 is repeated for all teeth subject to treatment.

[0089] A modified digital representation of the upper jaw 1' is generated as shown in FIG. 3 where a raised surface area 10 has been generated by virtually raising the defined surface areas 1-6, 2-6, 3-6, ... 13-6, 14-6, 15-6 defined as described above with respect to FIG. 2 for all the teeth in the upper jaw. The raised surface area 10 can be generated by raising each surface area separately. Alternatively the defined surfaces can also be joined as one surface and subsequently raised as one surface. For the current embodiment one or the other method does not provide any specific advantage, however, in cases where different doses of bleaching agent is needed for separate teeth the final receptacles can have different volumes if the surface areas are raised separately. Alternatively, by raising them together the design process can simplified and designs can be provided faster.

[0090] The raised surface area 10 may subsequently be smoothed or otherwise modified in order to remove e.g. undercuts in the physically manufactured bleaching tray.

[0091] Based on the modified digital representation of the upper jaw 1' a bleaching tray 11, shown in FIG. 4, can be manufactured. As also described herein at least two different methods are envisioned, however, modifications or alternatives thereto may be provided.

[0092] In a first manufacturing method a physical modified dental model is manufactured based directly on the modified digital representation of the upper jaw 1'. Thus a physical dental bleaching model having a raised surface area 10 is provided. The raised surface 10 can be generated by manipulating the surface area 8-6, or it can also be generated by adding a separate model layer by virtual painting on top of the surface aera 8-6.

[0093] Using traditional thermoforming manufacturing tools a polystyrene or polyvinylchloride (or other suitable material) sheet is pressed down over the dental model whereby a dental tray is generated. Due to the teeth representations on the dental model cavities are provided in the dental model for receiving the teeth and in addition a receptacle for receiving a bleaching agent is generated due to the raised surface area 10 on the tooth surface.

[0094] In a second manufacturing method a virtual model of a dental tray is generated based on the modified digital representation of the upper jaw 1' where a raised surface has been generated on the digital representation.

[0095] Alternatively the virtual model of the dental tray comprising the cavities and receptacle is based on unmodified three dimensional digital representation of a patients dentition where the receptacle(s) for receiving the bleaching agent without raising the surface area on the digital representation of the teeth but instead the surface area confined by the boundary segments is used to directly form the receptacle digitally in the virtual model of the dental tray.

[0096] This can for example be done by transferring/projecting the surface area from the tooth model onto the inside of the virtual model of the dental tray and subsequently offset/displace the wall structure of the dental tray a desired distance in the area defined by the surface area enclosed by the boundary segments.

[0097] A physical dental bleaching tray is subsequently manufactured directly based on the virtual model of the dental tray either from a single use mold or by direct 3D printing.

[0098] Both methods provides a physical dental tray 11 as shown in FIG. 4 having cavities 12 for receiving the patients teeth and receptacles 13 for receiving the bleaching agent.

[0099] Depending on how the raised surface area is designed the receptacles can in practice be

[0100] Although some embodiments have been described and shown in detail, the disclosure is not restricted to such details, 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 utilized and structural and functional modifications may be made without departing from the scope of the present invention. Also, the term virtual is understood as digital and vice versa.

[0101] A claim may refer to any of the preceding claims, and “any” is understood to mean “any one or more” of the preceding claims.

[0102] It should be emphasized that the term “comprises/ comprising/ including” when used in this specification is taken to specify the presence of stated features, integers, operations, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.

[0103] In 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.