[Development of a computer system for determining retentive force of cast clasps].

The purpose of this study is to develop a rational fabricating system for determining retentive force of cast clasps. The radius of curvature of a circumferential clasp arm is considered to be one of the important factors affecting dynamical properties of cast clasps. In this study, a device for determining the radius of curvature and a computer system for Akers clasps and I-bar clasps were developed. It was suggested to be very significant in partial denture designing, that the retentive force and the bending rigidity required according to various conditions around abutment teeth can be easily obtained by using a personal computer, and that the proper part of a commercially available clasp pattern required to fabricate cast clasps providing rational retentive forces can be determined in this system.