Authors : Abdol Hamid Alhavaz, Mohammad Ali Bagheri, Sadegh Pour Ahmadi, Mojtaba Ramezani and Ali Bijani
Abstract: When the zirconia core is fabricated in a uniform thickness and veneering porcelain has variable thicknesses, it maybe undergoes chipping. This study aimed to compare the fracture load of restorations fabricated with two different zirconia core designs. The 24 metal dies were divided into 2 groups for fabrication of zirconia cores: conventionally (0.5 mm thickness); customized design. After the porcelain was applied, the crowns were cemented. Using a universal testing machine a compressive vertical load was applieduntil failure. Data were analyzed with SPSS17, using t-test, X2-test and Mann-Whitney U test. The mean fracture loads were 2254.1773±404.4 and 2885.4327±670.5 N for conventional and customized zirconia core designs, respectively. Student’s t-test revealed that the fracture load of the customized group was significantly higher than that of the conventional group (p<0.001). Crowns with customized design have higher fracture resistance than those with conventional design.
Abdol Hamid Alhavaz, Mohammad Ali Bagheri, Sadegh Pour Ahmadi, Mojtaba Ramezani and Ali Bijani, 2017. Effect of Zirconia Coping Design on Fracture Resistance of Veneering Porcelain in All-Ceramic Posterior Crowns. Journal of Engineering and Applied Sciences, 12: 1623-1628.