Probability of Failure of Machined Zirconia Dental Ceramic Core Materials

The purpose of this study was to compare the probability of failure, expressed as B10 strength, of three systems of machined zirconia ceramics (Lava, DC-Zirkon, and Cercon) with a zirconia-reinforced aluminum ceramic (In-Ceram Zirconia). Ten rectangular specimens of each material were subjected to a three- point flexural strength test. The B10 strength of Lava was significantly lower than that of DC-Zirkon but significantly higher than that of Cercon and In-Ceram Zirconia. The B10 strength of Cercon and In-Ceram Zirconia were not significantly different from one another. The machined zirconia ceramics appeared to fail primarily with intergranular fracture. Int J Prosthodont 2009; 22: 340-341.