Patent ID: 7555403

Claim:
A computer method for reconstructing data associated with an obscured finish line, comprising: (a) providing to a computer processor, data of a 3D virtual model of at least a portion of an intraoral cavity comprising a preparation having a finish line, wherein at least a portion of the finish line is obscured; and configuring said computer processor to: (b) manipulate said data of a 3D virtual model in the vicinity of said obscured portion of said finish line in a virtual manner to create an auxiliary 3D virtual model that is displayable on a computer screen and corresponds to said obscured portion of said finish line; (c) provide topographical data of the finish line from the virtual model and the said auxiliary virtual model; (d) identify in said 3D virtual model a first virtual model part representing a dental site comprising said preparation and a second virtual model part representing at least soft tissues in abutting virtual contact with said first virtual model part; (e) manipulate said 3D virtual model wherein to separate said first virtual model part from said second virtual model part; (f) manipulate said first virtual model part wherein to create said auxiliary virtual model, comprising steps (g) and (h), wherein said computer processor is further configured to: (g) provide at least one cross section of said 3D virtual model along a working plane inclined to the occlusion plane, at least within said obscured finish line portion, said cross-section comprising a first cross-section profile representing said preparation and a second cross-section profile representing obscuring matter in abutting virtual contact with said first cross-section profile at a contact region; (h) extrapolate said first cross-section profile from said contact region to provide a third cross-section profile representing at least an approximation of a corresponding cross-section of said dental site below said obscuring matter and identify therein a corresponding element of said obscured finish line portion.