Objective: To evaluate wear of three CAD/CAM ceramics (Lithium Disilicate, Zirconia reinforced-lithium silicate, Zirconia-based) and their opposing enamel antagonist in addition to their microhardness & fracture toughness.
Materials and Methods: Thirty rectangular shaped samples (12 x 14 x 2 mm)were fabricated and divided into three groups according to the type of ceramic used (10 samples each):Group(IP): IPS e.max CAD, Group(VS):Vita Suprinity and Group(BZ): BruxZir. Each group was divided into two sub-groups (5 samples each) according to the testing procedure. The first sub-groups were subjected to microhardness and fracture toughness tests, while the second sub-groups were first weighed then subjected to wear test and finally re-weighed again before being subjected to microhardness and fracture toughness tests.
Results: Wear results showed a significant difference in weight loss of tested ceramics and the antagonist tooth structure between (BZ) and both (IP) & (VS) . Microhardness of the three ceramics were significantly different in each sub-group regardless of wear test. Regarding fracture toughness, there was a significant difference between (BZ) and both (IP) & (VS) in both sub-groups. For all tested ceramics, both sub-groups (without wear and after wear) were not statistically significantly different regarding microhardness and fracture toughness.
Conclusions: BruxZir showed the best wear behavior and the worst abrasiveness to enamel. Microhardness and fracture toughness were the highest for zirconia-based ceramic but both parameters were not affected by thermo-mechanical aging of wear test for the three tested ceramics.