| 摘要 |
<p>A method for generating a 3D model for a restoration is operative in a computer having a display. The method begins by obtaining a 3D model of the preparation. The preparation model may be obtained by an operator using a 3D digitizer. A "margin" curve on the preparation model is then determined. The method then continues by selecting a given 3D restoration cap model from a set of such models, where the set includes cap models that vary by one or more characteristics such as type, age, sex and ethnicity. The restoration cap model has a cap edge curve. According to the invention, the method then continues by fitting the restoration cap model over the preparation model (on the computer display) so that a minimum distance between the restoration cap and the restoration model is greater than a given minimum material thickness. The restoration cap model is then reshaped or otherwise scaled as necessary so that the restoration cap edge curve is related to the margin curve in a predetermined manner. In particular, preferably the cap edge curve is related to the margin curve by an angle from vertical that is equal or substantially equal to a given emergence angle at each point along the curve. To complete the model, a side surface is then created, preferably by lofting a surface from the margin curve to the cap edge curve.</p> |
