Reliability and fatigue damage modes of zirconia and titanium abutments

The fracture strength and accelerated fatigue reliability of metal and zirconia abutment systems were tested. Implants with either titanium (Ti, n = 9) or zirconia abutments(Zr, n = 18) were restored with metal crowns. Loads were applied as either a monotonic load to failure or mouth-motion cycles using a step-stress accelerated life testing method. At failure, monotonic loads were 1,475 +/- 625 N for Ti and 690 +/- 430 N for Zr. In step-stress testing, the Ti group was truncated at 70,000 cycles and a 900-N load with no fractures. In the Zr group, eight specimens survived and seven failed, with a maximum load of 400 N. Strength and reliability were significantly higher for the Ti abutments compared to the Zr. Int J Prosthodont 2010;23:56-59.