Patent ID: 7982731

Claim:
A method of processing a digitized three-dimensional model of a dental prosthetic item in the preparation of said item using a virtual tool, comprising the steps of: applying the virtual tool in a local zone of action of a surface of the model so as to change the height of said surface within the local zone of action, said local zone of action having an extent, and said local zone of action including a selected region, corresponding to a location of the virtual tool relative to the surface of said local zone of action, a modification region, which contains the selected region and also contains a structural feature of the surface of said local zone of action, an outer transition region surrounding the modified region, and having a surface which merges with a surface of the model surrounding said local zone of action; and an evaluation region whose area extent has a ratio of 1:5 to 1:200 to the extent of said local zone of action; and moving the virtual tool over the selected region to change the height of the surface of said local zone of action, the change in height being substantially constant over the modified region, and being non-constant over the outer transition region, and being substantially everywhere in a direction of a vector, wherein said vector is an average of normal vectors over the evaluation region, and the change in height not removing said structural feature located in the modified region.