PubMed ID (PMID): 20234894Pages 56-59, Language: EnglishMitsias, Miltiadis E. / Silva, Nelson R. F. A. / Pines, Mitchel / Stappert, Christian / Thompson, Van P.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.