Application of Composite Resin Coating Method for Cast Clasps. Part 1. Influence on Bending Rigidity of Clasp Arm.

The purpose of this study was to examine the bending profiles of composite resin coating cast clasps. The I-bar and Akers clasps made of cobalt-chromium alloy were cast using a tapered wax pattern. One of the chemical bonding methods (Silicoater MD, Kulzer Co.) wasapplied to adhere composite resin to a metal surface. The breakage and the bending rigidity ofcomposite resin coating clasps were evaluated.The results were as follows:1. There was no significant difference in the bending rigidities of clasp arms between beforeand after composite resin coating.2. After repeated bending tests to the tips of the clasp arm at 10, 000 times in 0.25mmdeflection, neither crack in composite resin surfaces nor separation in resin/metal interfaces wasoccurred in any specimen.From these results, it was indicated that the composite resin coating cast clasps could be appliedto clinical cases and the bending rigidities were controllable in the same way as conventional castclasps.