The Effect of Clasp Form on Permanent Deformation

This study was conducted to discover whether a relationship exists between clasp width-thickness ratios and wear or deformation. Five different forms of circumferential clasps were studied. The clasps were fabricated with a 160 degree curvature around an 8-mm (diameter) cylinder and cast in Ticonium alloy. The clasps were subjected to 1500 cycles of 0.01 inch flexure. The degree of permanent deformation was not related to clasp form or width-thickness ratio. Of the five forms, only one exhibited no permanent deformation. According to Duncan's Multiple Range Test, significant differences in wear against a steel tooth model were observed among the five clasp forms evaluated (alpha = 0.05).