A Study on Creating the Tooth Crown Basic Models Used in CAD System for Crown Restorations
The Creation of the Tooth Crown Basic Models of Molar Teeth
1997 Volume 41 Issue 5 Pages 787-795
Details
1997 Volume 41 Issue 5 Pages 787-795
In recent studies of CAD/CAM systems for crown restorations, the quantity of data of the basic model has been reduced to a minimum to transform three-dimensional shapes quickly. As a result, there is no model to represent a detailed tooth crown form like an occlusal surface. The purpose of this study was to create a tooth crown model showing minute coronal features. The results were as follows.
1. By dividing the occlusal surface into a grid pattern, solid models of molar teeth represented by bicubic Bézier surfaces were made from three-dimensional coordinate data of four times enlarged plaster models measured from five directions.
2. In order to represent the minute occlusal surface shapes of the molar teeth, it was necessary to divide the occlusal surfaces of the four times enlarged models into more than 1, 024 Bäzier surfaces, and the occlusal surfaces of the actual size models into more than 256 Bäzier surfaces.
3. In the premolar teeth, it was necessary to divide the occlusal surfaces of the four times enlarged models into more than 256 Bézier surfaces, and the occlusal surfaces of the actual size models into more than 64 Bézier surfaces.
4. Topological structure models may represent minute shapes efficiently with little data.
