The Measurement of Co-efficient of Friction between Cast Co-cr Alloy and Guiding Plane Materials - a Pilot Study

The purpose of this pilot investigation was to measure the co-efficient of friction of a cast cobaltchromium alloy specimen and three materials commonly found on the guiding surfaces of the teeth. The static .co-efficients of friction between dental cobalt-chromium alloy (before and after electropolishing) and tooth enamel, composite resin, and dental amalgam alloy were measured using an inclined plane method at 20 ± 1° C. The mean measured co-efficients of friction between cobalt — chromium alloy and dental composite resin, dental enamel, and dental amalgam alloy together with their standard deviations were 0.68 ± 0.03, 0.45 ± 0.03 and 0.58 ± 0.04 respectively. Electro-polishing had no effect. This limited experiment suggested that dental composite resin should be preferred to dental amalgam for the restoration of buccal or guiding plane surfaces of abutment teeth to enhance the retention of cobalt-chromium partial denture. However, other properties of these materials may need to be taken into account. On the basis of the results of this pilot study, further research is required to investigate the difference in values of the coefficient of friction between various types of composite resin and amalgam alloys commercially available. Index Words: Partial Denture Retention, Frictional Resistance, Abutment restoration.