Fatigue of resin cement-base metal alloy bond strength.

PURPOSE: Strong durable bonds between resin cements and metal alloys are critical to the success of resin-bonded, resin-veneered, or resin-retained prostheses. However, few comprehensive, comparative evaluations of materials or the fatigue effects of thermal cycling have been reported. The rate of strength loss may be a more important predictor of long-term success than bond strength. The purpose of this study was to investigate the effects of artificial aging by thermal cycling and resin cement type on the bond strengths to a base metal alloy.

MATERIAL AND

METHODS

This study investigated the effect of the number of thermal cycles (0, 1, 10, 100, 1,000, and 10,000) on the bond strengths of nine fixed prosthodontic resin cements. Specimens were assigned randomly to thermal cycle number/cement type test groups. Cylinders of a base metal alloy were bonded in an end-to-end configuration. One end of each bonded specimen was insulated, and the specimen was thermal cycled. Then, the bonds were tested in shear and bond strengths calculated.

RESULTS

Two-way ANOVA revealed that the effects of cement type, the number of thermal cycles, and their interaction all significantly affected bond strength (p < .0001). Multiple range analysis showed that some cements had significant trends to lose bond strength with thermal cycling (p < .05), while others did not (p > .05).

CONCLUSIONS

Both the type of resin cement and the amount of thermal cycling influenced bond strength to a base metal alloy. Some materials displayed more rapid loss of bond strength than others.