Patent ID: 7796811

Claim:
A method for designing at least one tooth surface of a digital dental prosthetic item existing as a 3D data set using a first 3D model of at least one of a preparation site and the digital dental prosthetic item, and a second 3D model, the second 3D model including regions which match at least some regions on the first 3D model and non-matching regions which differ from at least some other regions of said first 3D model, the non-matching regions containing at least some surface information required for the digital dental prosthetic item, the method comprising: selecting at least three pairs of points corresponding to each other on the first and second 3D models, wherein the at least three pairs are selected on at least one of matching regions of the first 3D model and the second 3D model, such that (1) a positional correlation of said second 3D model with reference to said first 3D model is determined with reference to said at least three pairs, (2) a sum of distances of the points on the first 3D model from the points on the second 3D model is minimized for the purpose of determining the positional correlation, and (3) portions of non-matching regions of said first and second 3D models are implemented for designing the at least one tooth surface of the digital dental prosthetic item taking into consideration the positional correlation.