Figure 6

Process of defining the axial area of prepared tooth based on the preparation margin area. (A) The lower (red line) and upper (blue line) boundaries of axial area of prepared tooth were geometrically generated from the location of the preparation margin (black line). (B) The lower boundary (dashed red line) was defined by finding the intersection polylines between the prepared tooth model and translating surface generated by the preparation margin. The upper boundary (dashed blue line) was defined as the intersection between the prepared tooth model and the curved surface generated by group of vertices that internally divide the points of the vertices on the surface generating the lower boundary and flat surface on the occlusal side (solid grey line).