“…In general, wear of a brittle materials, such as dental ceramics, occurs primarily due to crack growth mechanisms rather than plastic deformation (Oh et al, 2002). Factors that influence the wear behaviour of dental ceramics include ceramic type, microstructure, fracture toughness, surface quality/roughness, contact load, environment, and the number of cycles (Amer et al, 2014;Etman et al, 2013;Hmaidouch and Weigl, 2013;Hopp and Land, 2013;Miyazaki et al, 2013;Mundhe et al, 2015;Oh et al, 2002;Peng et al, 2016;Stawarczyk et al, 2013;Suputtamongkol et al, 2010;Wang et al, 2012). However, perhaps surprisingly, there is no strong correlation between a cera ic's hardness and wear of opposing enamel (Hmaidouch and Weigl, 2013;Miyazaki et al, 2013).…”