Prosthodontic Insights NewsletterOctober 1999 Volume 12, Number 2Continues..Flexure Test on Dental Ceramic The failure stresses in flexural tests of a densely-sintered high-purity alumina (Procera® AllCeram) were evaluated using three point bend, ring-on-ring, and piston-on-three-ball tests. Glass-infiltrated alumina (In-Ceram) and leucite-reinforced porcelain (IPS Empress) discs with the same dimensions were also tested using ring-on-ring and piston-on-three-ball tests. The failure stresses for all materials were substantially different (up to 50%) with different testing methods, and cannot be directly compared. However, by considering the effective specimen area under the maximum tensile stress, this failure stress data could be compared. The results emphasize the importance of knowing the test method of calculation when comparing data. These three methods were also subjected to Weibull analysis. The Procera® AllCeram had a consistently higher failure stress than the other two materials. Int J Prosthodont 1996 9 (5) p.434-439. |
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