Comparison of the retentive characteristics of cobalt-chromium and commercially pure titanium clasps using a novel method.

This study aimed to compare the retentive forces of cast cobalt-chromium (Co-Cr) and commercially pure titanium (cpTi) clasps. A clasp assembly comprising a pair of symmetrical clasps was made to fit the opposite halves of a hardened stainless-steel sphere. This twin clasp was designed to counterbalance the tipping forces when the clasp assembly was drawn from the sphere.

Longevity of two-unit cantilevered resin-bonded fixed partial dentures.

Purpose: To examine the clinical performance of two-unit cantilevered resin-bonded fixed partial dentures that were inserted at The Prince Philip Dental Hospital, Hong Kong by students and staff between 1992 and 1998.

Materials And Methods: A search of the Hospital computer records system revealed a list of 130 patients who had received two-unit cantilevered resin-bonded fixed partial dentures (RBFPD) placed more than 24 months previous to the review date. For each patient clinically examined, the following data were recorded: gender, age, operator, cementation date, endodontic treatment if performed, bone support, tooth mobility, the presence of shimstock contacts on abutment or pontic in intercuspal position, the presence of interproximal contacts adjacent to the prosthesis assessed by dental floss.