# US 11,998,410 B2 · Tooth shading, transparency and glazing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,998,410 B2 - Document ID: US11998410B2 - Status: Granted - Kind: B2 - Application number: 18/183,912 - Filed: 2023-03-14 - Published: 2023-09-14 - Granted: 2024-06-04 - Earliest claimed: 2017-07-27 - Assignees: Align Technology, Inc. - Applicants: Align Technology, Inc. - Inventors: Yosi Moalem; Gilad Elbaz; Ofer Saphier; Maayan Moshe; Shai Ayal; Doron Malka - Web page: https://patentgrep.com/patent/US11998410B2 ## CPC - A61C 13/082: {Cosmetic aspects, e.g. inlays; Determination of the colour (A61C19/10 takes precedence)} - A61C 9/0053: {Optical means or methods, e.g. scanning the teeth by a laser or light beam} - A61C 13/0004: {Computer-assisted sizing or machining of dental prostheses} - G06T 15/08: Volume rendering - G06T 17/00: Three-dimensional [3D] modelling for computer graphics - A61C 13/0019: {using three dimensional printing} - A61C 13/09: {Composite teeth, e.g. front and back section (A61C13/0835, A61C13/1023 take precedence)}; Multilayer teeth - G06T 2210/41: Medical - A61C: DENTISTRY; APPARATUS OR METHODS FOR ORAL OR DENTAL HYGIENE (non-driven toothbrushes A46B; {tongue scrapers A61B17/24;} preparations for dentistry A61K6/00; preparations for cleaning the teeth or mouth A61K8/00, A61Q11/00) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL ## Abstract Systems, methods, and/or computer-readable media described herein provide technical solutions to aid in the color matching of dental restorations. These systems, methods and/or computer readable media may receive a three-dimensional (3D) model of a tooth, where the 3D model includes a plurality of voxels, set each voxel to a starting optical property, and form a 3D visible light model from the 3D model by iteratively adjusting the optical property of each voxel based on optical properties measured from a scan of the tooth, where the 3D visible light model provides information to generate a color matched dental restoration. ## Claims ### Claim 1 A system for color matching a dental restoration for a tooth of a patient, the system comprising: one or more processors; and one or more non-transitory computer readable media storing instructions for execution by the one or more processor that, when executed, cause the one or more processor to perform a method comprising: receiving or generating a three-dimensional (3D) model of the tooth, the 3D model including a plurality of voxels forming an internal structure corresponding to a region between an outer enamel surface of the tooth and an outer surface of the dentine, wherein the dimensions of the region are based on a scan of the tooth or of a tooth that is complementary to the tooth; setting each voxel of the plurality of voxels to one or more starting optical property values; and forming a 3D visible light model from the 3D model by iteratively adjusting the starting optical property value for each voxel based on one or more optical property values measured from the scan corresponding to a plurality of locations and angles, for a camera taking the scan, relative to the tooth or to the tooth that is complementary to the tooth, until the adjusted optical properties converge to a value within an acceptable range of the one or more optical property values measured from the scan, wherein the 3D visible light model provides information for generating the dental restoration that is color matched to the patient's tooth. ### Claim 2 (depends on 1) The system of claim 1, wherein iteratively adjusting the one or more starting optical property values includes solving for optical properties based on a plurality of positions and angles of the camera. ### Claim 3 (depends on 1) The system of claim 1, wherein the one or more starting values are one or more predetermined prior values determined by parametric estimation. ### Claim 4 (depends on 1) The system of claim 1, wherein the one or more starting values are one or more predetermined prior values based on a population of representative patients. ### Claim 5 (depends on 1) The system of claim 1, wherein the one or more starting values are one or more predetermined prior values based on an average color. ### Claim 6 (depends on 1) The system of claim 1, wherein the method further comprises receiving the scan. ### Claim 7 (depends on 1) The system of claim 1, wherein the method further comprises fabricating the dental restoration using the 3D visible light model. ### Claim 8 (depends on 1) The system of claim 1, wherein the optical properties comprise one or more of: light absorption, light reflection, light transmission, and light scattering. ### Claim 9 (depends on 1) The system of claim 1, wherein adjusting the starting optical property value for each voxel based on one or more optical property values measured from the scan corresponding to a plurality of locations and angles comprises calculating the one or more optical properties as a difference between a contribution of the outer enamel surface and a contribution from a length to the dentine from a voxel location. ### Claim 10 A method of color matching a dental restoration for a tooth of a patient, the method comprising: receiving or generating a three-dimensional (3D) model of the tooth, the 3D model including a plurality of voxels forming an internal structure corresponding to a region between an outer enamel surface of the tooth and an outer surface of dentine, wherein the dimensions of the region are based on a scan of the tooth or of a tooth that is complementary to the tooth; setting each voxel of the plurality of voxels to one or more starting optical property values; and iteratively adjusting the starting optical property value for each voxel based on one or more optical property values measured from the scan corresponding to a plurality locations and angles of a camera taking the scan relative to the tooth or the tooth that is complementary to the tooth, until the adjusted optical properties converge to a value within an acceptable range of the one or more optical property values measured from the scan. ### Claim 11 (depends on 10) The method of claim 10, wherein iteratively adjusting the one or more starting optical property values includes solving for optical properties based on a plurality of positions and angles of the camera. ### Claim 12 (depends on 10) The method of claim 10, wherein the one or more starting values are one or more predetermined prior values determined by parametric estimation. ### Claim 13 (depends on 10) The method of claim 10, wherein the one or more starting values are one or more predetermined prior values based on a population of representative patients. ### Claim 14 (depends on 10) The method of claim 10, wherein the one or more starting values are one or more predetermined prior values based on an average color. ### Claim 15 (depends on 10) The method of claim 10, wherein the method further comprises receiving the scan. ### Claim 16 (depends on 10) The method of claim 10, wherein the method further comprises fabricating the dental restoration using a 3D visible light model. ### Claim 17 (depends on 10) The method of claim 10, wherein the optical properties comprises one or more of: light absorption, light reflection, light transmission, and light scattering. ### Claim 18 (depends on 10) The method of claim 10, wherein adjusting the starting optical property value for each voxel based on one or more optical property values measured from the scan corresponding to a plurality of locations and angles comprises calculating the one or more optical properties as a difference between a contribution of the outer enamel surface and a contribution from a length to the dentine from a voxel location. ### Claim 19 A non-transitory computer readable medium storing instructions for execution by a processor that, when executed, cause the processor to perform a method comprising: receiving or generating a three-dimensional (3D) model of a tooth, the 3D model including a plurality of voxels forming an internal structure corresponding to a region between an outer enamel surface of the tooth and an outer surface of dentine, wherein the dimensions of the region are based on a scan of the tooth or of a tooth that is complementary to the tooth; setting each voxel of the plurality of voxels to one or more starting optical property values; and iteratively adjusting the starting optical property value for each voxel based on one or more optical property values measured from the scan corresponding to a plurality locations and angles of a camera taking the scan relative to the tooth or the tooth that is complementary to the tooth, until the adjusted optical properties converge to a value within an acceptable range of the one or more optical property values measured from the scan.