New approach for making accurate cross sections of casts

This article describes a new procedure for producing cross sections of a cast, a denture, or an impression and a method of presenting the results in graphic form to show variance. To test the method, identically colored, duplicate dentures were embedded in plaster blocks formed from a precisely engineered and calibrated brass box. A modified jig and saw allowed the plaster blocks to be positioned, held, and sectioned at any required location with a high degree of accuracy. The sectioned surfaces of the duplicate dentures were scanned. The resultant profiles were registered in location frames on the computer screen, traced by computer to produce outlines, and printed onto transparent film for the purpose of comparison. In vitro results showed the relationship between congruent outer forms and provided clear visual evidence of the accuracy of the procedure used and a way to further in vivo use.