# US 10,245,126 B2 · Method of making a dental restoration by matching tooth color structure from an image of a tooth with block color structure of a restorative material > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,245,126 B2 - Document ID: US10245126B2 - Status: Granted - Kind: B2 - Application number: 15/515,238 - Filed: 2015-10-16 - Published: 2017-08-17 - Granted: 2019-04-02 - Earliest claimed: 2014-11-07 - Assignees: 3M Innovative Properties Company - Applicants: 3M Innovative Properties Company - Inventors: Malte Korten; Helmar B. Mayr - Web page: https://patentgrep.com/patent/US10245126B2 ## CPC - A61C 13/082: {Cosmetic aspects, e.g. inlays; Determination of the colour (A61C19/10 takes precedence)} - A61B 1/24: for the mouth, i.e. stomatoscopes, e.g. with tongue depressors; Instruments for opening or keeping open the mouth - A61C 13/0004: {Computer-assisted sizing or machining of dental prostheses} - A61C 13/0022: {Blanks or green, unfinished dental restoration parts} - A61C 13/09: {Composite teeth, e.g. front and back section (A61C13/0835, A61C13/1023 take precedence)}; Multilayer teeth - G01J 3/463: {Colour matching} - G01J 3/508: {measuring the colour of teeth} - G06T 7/0014: {using an image reference approach} - G06T 7/12: Edge-based segmentation - G06T 7/90: Determination of colour characteristics - A61C 19/10: Supports for artificial teeth for transport or for comparison of the colour - G06T 2207/30036: Dental; Teeth - G16H 20/40: relating to mechanical, radiation or invasive therapies, e.g. surgery, laser therapy, dialysis or acupuncture - 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) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) - G06T: IMAGE DATA PROCESSING OR GENERATION, IN GENERAL - G16H: HEALTHCARE INFORMATICS, i.e. INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR THE HANDLING OR PROCESSING OF MEDICAL OR HEALTHCARE DATA ## Abstract A method of making a dental restoration has the steps of capturing an image of a tooth, posterizing the image, determining a tooth color structure, providing information about a multicolored block having a block color structure, matching the tooth color structure and the block color structure, based on the matching, determining a position within the block in which the tooth color structure and the block color structure match, and machining the dental restoration from the block at the determined position. The invention helps facilitating the making of dental restorations at maximized aesthetics. ## Claims ### Claim 1 A method of making a dental restoration, comprising the steps of: capturing an image of a tooth at a color depth that is based on a multiplicity of color values; posterizing the image by: detecting in the tooth image a contiguous first tooth color area having color values within a predetermined first range of different color values and assigning the first tooth color area one common first false color value; and detecting in the tooth image a contiguous second tooth color area having color values within a predetermined second range of different color values and assigning the second tooth color area one common second false color value; determining a tooth color structure based on the first and second false color value of the first and second color area, respectively, within the tooth image; providing information about a multicolored block that has a predetermined color shading formed by at least a first block color zone and a second block color zone, wherein the information comprises data about a block color structure with respect to dimensions and/or positions of the first and second block color zone; matching the tooth color structure and the block color structure; and based on the matching; determining a position within the multicolored block in which the tooth color structure and the block color structure match within predetermined limits; and machining the dental restoration from the multicolored block at the determined position. ### Claim 2 (depends on 1) The method of claim 1, wherein the step of capturing the tooth image further comprises taking a two-dimensional photograph from the tooth. ### Claim 3 (depends on 2) The method of claim 2, wherein the step of capturing the tooth image further comprises determining an outline of the tooth based on the two-dimensional photograph and thereby creating the tooth image. ### Claim 4 (depends on 1) The method of claim 1, wherein the step of posterization is based on thresholding. ### Claim 5 (depends on 1) The method of claim 1, wherein the first false color value and the second false color value each correspond to a value in a grey scale or correspond to black and white, respectively. ### Claim 6 (depends on 1) The method of claim 1, further comprising the steps of: providing a database holding information about a plurality of blocks with each of the blocks having a shade structure in accordance with the first block color zone and the second block color zone, wherein each block being assigned an overall block color code which is based on the colors of the first block color zone and the second block color zone in combination; determining a tooth color code; and selecting a block having a block color code corresponding to the tooth color code. ### Claim 7 (depends on 6) The method of claim 6, further comprising the step of: determining an average color value from the tooth image and calculating the tooth color code. ### Claim 8 (depends on 6) The method of claim 6, further comprising the step of: determining the tooth color code by matching a physical shade guide and the tooth. ### Claim 9 (depends on 1) The method of claim 1, further comprising the steps of: displaying at least part of the tooth image and the tooth color structure; and modifying boundaries of the tooth color structure based on user input. ### Claim 10 (depends on 1) The method of claim 1, further comprising the steps of: providing a three-dimensional virtual model of the dental restoration; and creating a positional relationship between the tooth color structure and the dental restoration model; and wherein the step of machining the dental restoration is controlled based on the dental restoration model. ### Claim 11 (depends on 10) The method of claim 10, further comprising the steps of: scanning a patient's teeth; designing the dental restoration based on the scan and thereby provide the dental restoration model; and transferring the dental restoration model by data transfer to a machine for machining the dental restoration. ### Claim 12 (depends on 1) The method of claim 1, wherein the block is made of a ceramic or glass ceramic material. ### Claim 13 (depends on 1) The method of claim 1, wherein the step of machining the dental restoration involves milling and/or grinding. ### Claim 14 (depends on 13) The method of claim 13, wherein the dental restoration is machined at a position in which the tooth color structure and the block color structure match, wherein the position is determined based on the tooth color code.