A Study on Three-Dimensional Measurement and Restoration of Tooth Crown-Form (by CAD/CAM)

Abstract

The purpose of this study was to examine the technical possibility of fabricating crowns by using CAD/CAM. First, it was attempted to construct a crown-form model by NC milling, based on threedimensionalmeasurement data obtained by a touch probe. Next, it was attempted to fabricate the metal crownby NC milling and spark erosion, based on three-dimensional measurement data obtained by a touch probe orlaser scanning.
The results were as follows:
1. The crown-form model fabricated according to three-dimensional measurement data obtained by atouch probe was restored accurately, compared with the original crown-form model. The differences in thethree-dimensional data of occlusal surfaces between the two models were 20-100μm.
2. The crown-form model fabricated according to three-dimensional measurement data obtained by laserwas not restored accurately, compared with the original crown-form.
3. It was possible to fabricate a metal crown by NC milling and spark erosion. Therefore, it wasconfirmed that fabrication of crowns by CAD/CAM is technically possible.