Compressive Strength Evaluation between Metal Ceramic and Zirconia Crowns.An In-Vitro Study

The aim of this study is to evaluate the compressive strength of metal and zirconia cores and also the point of chipping of the veneered porcelain to both the core materials. For the present study, full coverage crowns were fabricated for mandibular molar. The crowns were divided into two groups. First group is five samples of metal ceramic crowns and second group is five samples of zirconia ceramic crowns. These crowns were subjected to static compression loading in a universal testing machine until the fracture of the veneering porcelain. The compressive load was recorded in newton. Data were subjected to student t test analysis. Mean compressive strength for group 1 metal ceramic crowns was 2587.80N and the mean compressive strength for group 2 zirconia ceramic crowns was 1361.00N. The compressive strength of metal when being used as a core material is significantly higher than zirconia. Under static compressive loading, the point of fracture of the veneered porcelains occurred at significantly lower values for the zirconia based restorations when compared to that of metal ceramic restorations.