Determination of the fracture toughness of GI-IIinfiltrated ceramic

Objective: This study was to compare fracture toughness and hardness of GI-ⅡInfiltrated Ceramic and In-ceram using indentation method. Methods: GI-II infiltrated ceramic and In-ceram disks were fabricated and polished. Their fracture toughness and hardness were determined with Vicker's indentation test machine. The fracture toughness data was processed by Weibull analysis. Results: The fracture toughness and hardness were 3.05±0.06MN·m-1.5 and 12.66±0.33GPa for GI-ⅡInfiltrated Ceramic, 3.86±0.25MN·m-1.5 and 14.63±0.43GPa for In-ceram. The Weibull Modulus of the fracture toughness was 46.93 and 15.00, respectively.Conclusion: GI-ⅡInfiltrated Ceramic is lower in fracture toughness and hardness than In-ceram, but much higher than many other traditional dental restorative ceramics and its higher Weibull modulus indicate better homogeneity.