Designing a virtual preparation and a virtual gingival

1. A method for manufacturing a combined model for use in planning, visualization and manufacturing of a dental component for a patient's set of teeth so that the patient and dental practitioner can see how the set of teeth will look after the dental component is installed, where the method comprises:

obtaining a digital 3D representation of a pre-prepared set of teeth showing the region for which the dental component is intended;

providing a 3D virtual model of the dental component showing a desired shape of the teeth of the dental component;

generating a 3D virtual combined model expressing a target dental situation for the patient when the dental component is arranged at the teeth, where the generating comprises virtually replacing one or more teeth of the digital 3D representation of the pre-prepared set of teeth with the 3D virtual model of the dental component by virtually removing the one or more teeth of the digital 3D representation of the pre-prepared set of teeth and adding the 3D virtual model of the dental component to the digital 3D representation of the pre-prepared set of teeth; and

manufacturing the combined model from the 3D virtual combined model.

2. The method according to claim 1 , wherein the virtually replacing one or more teeth comprises virtually removing the one or more teeth from the digital 3D representation of the pre-prepared set of teeth.

3. The method according to claim 2 , wherein a 3D sectioning spline is created in relation to the digital 3D representation of the pre-prepared set of teeth, and the portion of the digital 3D representation of the pre-prepared set of teeth which is deleted when virtually removing at least one tooth is defined and bounded by said 3D sectioning spline.

4. The method according to claim 3 , wherein the method comprises manually defining the 3D sectioning spline or manually adjusting an automatically generated 3D sectioning spline.

5. The method according to claim 2 , wherein generating the 3D virtual combined model comprises generating a virtual inter-proximal surface configured for closing an inter-proximal part of a hole formed in the digital 3D representation of the pre-prepared set of teeth by the virtual removal of a tooth.

6. The method according to claim 5 , wherein the virtual inter-proximal surface is generated based on the shape of a neighboring tooth.

7. The method according to claim 6 , wherein the virtual inter-proximal surface is generated using a polynomial algorithm.

8. The method according to claim 2 , wherein generating the 3D virtual combined model comprises generating a virtual gingiva configured for closing a gingival part of the hole in the digital 3D representation of the pre-prepared set of teeth resulting from the virtual removal of a tooth.

9. The method according to claim 8 , wherein the method comprises at least partly replacing the virtually removed tooth with the generated virtual gingiva.

10. The method according to claim 8 , wherein the virtual gingiva is generated based on the digital 3D representation of the pre-prepared set of teeth.

11. The method according to claim 10 , wherein the virtual gingiva is generated based on part of the digital 3D representation of the pre-prepared set of teeth expressing the shape of the surrounding gingiva.

12. The method according to claim 8 , wherein generating the virtual gingiva comprises selecting a gingiva profile template from a library of gingiva profile templates and modifying the selected gingiva profile template to fit the patient's set of teeth.

13. The method according to claim 8 , where the virtual gingiva at least partly is generated by freeform modeling using flexible sculpt tools.

14. The method according to claim 8 , wherein the virtual gingiva at least partly is shaped using a number of control points assigned to the virtual gingiva.

15. The method according to claim 8 , wherein the virtual gingival is generated at the position in the digital 3D representation corresponding to the position at which a pontic of the dental component is to be arranged.

16. The method according to claim 1 , wherein the method comprises hole-closure of the combined model such that holes appearing at the location where the 3D virtual model of the dental component and the digital 3D representation connect are closed.

17. The method according to claim 1 , wherein the dental component is a bridge restoration.

18. The method according to claim 1 , wherein the physical combined model is manufactured from the 3D virtual combined model by direct digital manufacturing.