Effect of Cementation and Thermomechanical Aging on the Marginal Adaptation of Veneered and Monolithic Zirconia

Objective: The objective of current study was to evaluate the marginal discrepancy of a manually veneered CAD/CAM zirconia and two different monolithic CAD/CAM zirconia all-ceramic crowns; before and after cementation; before and after artificial aging by using a chewing simulator. Methods: A total of 36 specimens were divided into 3 groups (n=12) and crown restorations were fabricated by using 3 different type of zirconia materials for each group: Group MZ1: monolithic zirconia crowns (GC initial), Group MZ2: monolithic zirconia crowns (InCoris TZI), Group BZ: bilayered zirconia crowns; zirconia core (InCoris ZI) veneered with a low-fusing glass-ceramic. The specimens were duplicated using epoxy resin before and after cementation and after thermo-mechanical fatigue. The marginal adaptations of replicated specimens were evaluated at six points. The margins were evaluated under a scanning electron microscope. Statistical analysis was performed using SPSS. Tukey HSD test were used to investigate the differences between the three types of zirconia crown restorations. Statistically significant difference was determined at (p