Mechanical Property of Super-elastic Ti-Ni Alloy as Castclasps.

In order to apply super-elastic Titanium-Nickel alloy to castclasps, retention forces and deformation degrees of Ti-Ni alloy castclasps were investigated in comparison with those of conventional cobaltchromium alloy in this study.In the setting-removing test, retention forces of castclasps and their changes during the test were measured with Akers type clasps and I bar type clasps with the tooth model. Two directions for settingremoving were tested. One is the designed direction and the other is the 30 degrees declined one. The retention forces of Ti-Ni castclasps changed very little in both setting-removing directions. In case of Co-Cr castclasps, the retention forces decreased obviously in both directions.In the bending test, deformation of Ti-Ni alloy and Co-Cr alloy were measured. Deformation of Ti-Ni alloy also changed very little after 1.0 mm and 3.0 mm displacement. However, Co-Cr alloy was greatly deformed in both 1.0 mm and 3.0 mm displacement.Considering from these results, Ti-Ni alloy having the superelasticity could be a promising dental material for castclasps in prosthodontics