Detecting tooth shade

1. A method for determining shade of a patient's tooth, wherein the method comprises:

obtaining a digital 3D representation of the tooth, where the digital 3D representation comprises shape data and texture data for the tooth;

determining a tooth shade value for at least one point on the tooth based on the texture data of the corresponding point of the digital 3D representation and on known texture values of one or more reference tooth shade values;

deriving a certainty score expressing the certainty of the determined tooth shade value; and generating a visual representation of the certainty score and displaying this visual representation in a user interface, wherein the visual representation of the certainty score is at least one of a binary code, a bar structure with a color gradient, a numerical value, and a comparison between the texture date and the known texture value of the determined tooth shade value.

2. The method according to claim 1 , wherein determining the tooth shade value for the point comprises selecting the reference tooth shade value with the known texture value closest to the texture data of the point.

3. The method according to claim 1 , wherein the visual representation of the certainty score is displayed together with or is mapped onto the digital 3D representation of the tooth.

4. The method according to claim 1 , wherein determining the tooth shade value for the point comprises an interpolation of the two or more reference tooth shade values having known texture values close to the texture data of the point.

5. The method according to claim 1 , wherein the method comprises comparing the derived certainty score with a range of acceptable certainty score values.

6. The method according to claim 1 , wherein the certainty measure relates to how uniform the sub-scan texture information is at the point, and/or to how close the texture data is to the known texture value of the determined tooth shade value, and/or to the amount of texture information used to derive the texture data at the point.

7. The method according to claim 1 , wherein the one or more reference tooth shade values relate to shade values for natural teeth with intact surface and/or to shade values for teeth prepared for a dental restoration.

8. The method according to claim 1 , wherein the method comprises comparing the texture data with known texture values for soft oral tissue.

9. The method according to claim 1 , wherein the texture information comprises at least one of tooth color or surface roughness.

10. The method according to claim 1 , wherein the method comprises creating a shade profile for the tooth from shade values determined one or more points on the tooth.

11. The method according to claim 10 , wherein the tooth shade profile comprises a one or more tooth shade regions on the tooth surface where an average tooth shade is derived for each region from tooth shade values determined for a number of points within the region.

12. The method according to claim 1 , wherein obtaining the digital 3D representation of the tooth comprises recording a series of sub-scans of the tooth, where at least one of said sub-scans comprises both texture information and geometry information for said tooth, and generating the digital 3D representation of the tooth from the recorded series of sub-scans.

13. The method according to claim 12 , wherein the texture data at least partly are derived by combining the texture information from corresponding parts of a number of the sub-scans.

14. The method according to claim 13 , wherein combining the texture information from the sub-scans comprises interpolating the texture information and/or calculating an average value of the texture information.

15. The method according to claim 14 , wherein the calculated average value is a weighted average of the texture information.

16. The method according to claim 1 , wherein the method comprises generating a certainty score profile at least for a portion of the tooth, where the certainty scope profile represents the certainty scores for tooth shade values determined for a number of points on the tooth.

17. The method according to claim 16 , wherein the method comprises mapping the certainty score profile onto the digital 3D representation of the tooth.

18. A user interface for determining and displaying shade of a patient's tooth, wherein the user interface is configured for:

obtaining a digital 3D representation of the tooth, said digital 3D representation comprising shape data and texture data for the tooth;

displaying at least the shape data of the digital 3D representation such that the shape of the tooth is visualized in the user interface;

determining a tooth shade value for at least one point on the tooth based on the texture data of the corresponding point of the digital 3D representation and on known texture values of one or more reference tooth shade values;

deriving a certainty score expressing the certainty of the determined tooth shade value generating a visual representation of the certainty score and displaying this visual representation in a user interface, wherein the visual representation of the certainty score is at least one of a binary code, a bar structure with a color gradient, a numerical value, and a comparison between the texture data and the known texture value of the determined tooth shade value; and

displaying the determined tooth shade value.

19. The user interface according to claim 18 , wherein the user interface is configured to generate a certainty score profile at least for a portion of the tooth, where the certainty scope profile represents the certainty scores for tooth shade values determined for a number of points on the tooth, and to map the certainty score profile onto the digital 3D representation of the of the tooth.

20. The user interface according to claim 19 , wherein the user interface is configured to allow a user to toggle between having the tooth shade profile and having the certainty scope profiled visualized on the digital 3D representation.

21. A method for determining shade of a patient's tooth, wherein the method comprises:

obtaining a digital 3D representation of the tooth, where the digital 3D representation comprises shape data and texture data for the tooth;

determining a tooth shade value for at least one point on the tooth based on the texture data of the corresponding point of the digital 3D representation and on known texture values of one or more reference tooth shade values; and

creating a shade profile for the tooth from shade values determined one or more points on the tooth, where the tooth shade profile comprises a one or more tooth shade regions on the tooth surface where an average tooth shade is derived for each region from tooth shade values determined for a number of points within the region.

22. A method for determining shade of a patient's tooth, wherein the method comprises:

obtaining a digital 3D representation of the tooth, where obtaining the digital 3D representation of the tooth comprises recording a series of sub-scans of the tooth, where at least one of said sub-scans comprises both texture information and geometry information for said tooth, and generating the digital 3D representation of the tooth from the recorded series of sub-scans such that the digital 3D representation comprises shape data and texture data for the tooth, where the texture data at least partly are derived by combining the texture information from corresponding parts of a number of the sub-scans by calculating a weighted average value of the texture information; and

determining a tooth shade value for at least one point on the tooth based on the texture data of the corresponding point of the digital 3D representation and on known texture values of one or more reference tooth shade values.