Patent ID: 8111909

Claim:
A system, comprising: a memory arranged to store a first 3D model of at least one of a preparation site and a digital dental prosthetic item, and a second 3D model that includes 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 useable for constructing the digital dental prosthetic item; and a controller, responsive to at least three pairs of points being selected on at least one of the matching regions of the first 3D model and the second 3D model to (1) determine a positional correlation of said second 3D model with reference to said first 3D model with reference to said at least three pairs, and (2) minimize a sum of distances of the points on the first 3D model from the points on the second 3D model for the positional correlation, portions of the non-matching regions of said first and second 3D models being useable for designing the at least one tooth surface of the digital dental prosthetic item based on the positional correlation.