For the past 10 years, we have been engaged in research on development of CAD/CAM system for prosthetic restoration such as crown and bridge in molar teeth. In order to apply this system to anterior teeth, it is necessary to create the crown basic model data of the anterior teeth. The purpose of this study was to complete a library of basic crown model data of all teeth for the CAD system.
The results were as follows:
1. By dividing the incisal edge or the cuspid into a grid pattern, solid models of anterior teeth represented by bicubic Bezier surfaces were made from three-dimensional coordinate data of four-fold enlarged plaster models measured from five directions.
2. In order to represent the coronal anatomical features of the anterior teeth, it was necessary to divide the four-fold enlarged models into more than 104 Bezier surfaces, and the real size models into more than 43 Bezier surfaces.
3. The results suggested that consideration of the functional crown forms of the natural teeth may be necessary to decide the most suitable surface for basic crown models.