Influence of cementation variables on fatigue of simulated two-unit cantilever resin-bonded fixed partial dentures

PURPOSE: To determine the influence of various combinations of surface pretreatment and luting cement on flexural fatigue limits of two-unit CoCr cantilever resin-bonded fixed partial dentures. METHODS: Cyclic fatigue tests were performed at 1 Hz on an ACTA fatigue tester. The staircase test method was used on CoCr beams, simulating cantilever resin-bonded fixed partial dentures, using flat ground bovine teeth as substrate. Two series of tests have been executed: (1) 10(4) cycles, and (2) 10(5) cycles. Prior to cementation, the CoCr beams were subjected to either sandblasting or Rocatec or Silicoater treatments. Three commercially available resin luting cements were used. Fatigue tests were performed 72 hours after cementation and storage in 37 degrees C tap water. Each possible combination of cement and pretreatment (n = 20) was tested. RESULTS: One cement, UniFix, showed hardly any debondings with any of the three surface pretreatments. The other two cements, RelyX ARC and Panavia, both showed significantly better performance with Rocatec than when pretreated with sandblasting or Silicoater.