Evaluation of Wear and Surface Roughness of Different CAD/CAM Monolithic Ceramic Materials

ABSTRACT
Purpose: To evaluate the wear and surface roughness of different CAD/CAM monolithic ceramic materials opposing monolithic zirconia.
Material and Methods: Twenty-seven rectangular-shaped specimens were milled from different ceramic materials by using a precision saw and divided (n=9) into 3 groups: group ZLS, zirconia-reinforced lithium silicate; group LD, lithium disilicate glass ceramic; and group ZR, 4-mol yttria-stabilized tetragonal zirconia polycrystal (4Y-TZP). Antagonist material were milled from a partially sintered 4Y-TZP blank with a CAD/CAM system. Two-body wear test was performed in a mastication simulator. The wear of the specimens and antagonists was determined by calculating the weight loss. The surface roughness of the specimens and antagonists before and after wear testing was analyzed by using a digital image analysis software program. The surfaces of ceramic specimens and antagonists were inspected by using scanning electron microscopy. Data were statistically analyzed by using 1-way ANOVA and the Tukey post hoc test (p = 0.05).
Results: One-way ANOVA revealed significant amount of weight loss for all ceramic types (p < 0.05). No statistically significant differences were found between the different ceramic types when comparing their percentage change of weight (p = 0.544). As for the surface roughness, one-way ANOVA revealed significant increase in surface roughness for all ceramic types after chewing simulation (p < 0.05). No statistically significant differences were found between the different ceramic types when comparing their percentage change roughness (p = 0.251).
Conclusions: The different types of tested ceramics showed similar wear resistance when opposed to monolithic zirconia.