Abstract
The recent introduction of monolithic zirconia to dentistry brings zirconia into direct contact with the tooth material, potentially increasing the risk of tooth material wear because of the mechanical mismatch between the tooth and zirconia. However, the effect of mechanical properties on the wear behaviour of the materials is controversial. The aim of this study is to review the in vivo and in vitro studies on wear performance of monolithic zirconia against human enamel antagonists, to present and analyse the factors that control and modify the wear behaviour of monolithic zirconia in this tribological system. In depth discussion of the effect of the type of surface finish, surface roughness and aging on wear behaviour of zirconia was presented, in addition to a comparison with wear behaviour of other dental ceramic materials.
The findings indicate that, in terms of surface finish, there is agreement that polishing reduces wear of the human enamel, however, this surface quality is not quantified. Additionally, standard polishing protocols for zirconia are yet to be specified. Comparing the results between different studies must be based on the total sliding distance rather than the number of wear cycles. Also, the variation in the stress generated during wear simulation occurred because of the differences in the applied force and contact surface area between the tested materials complicates the comparison further. Finally, there is a lack of distinction in the literature between the different zirconia products which excludes comparing the results of the different studies and therefore undermines the strength of the systematic reviews.
•The surface roughness value at which zirconia's abrasiveness decreases is unknown.•Standard polishing protocols for zirconia are yet to be specified.•Total sliding distance should be used to compare the results of different studies.•The variation in the in vitro test settings complicate results comparison.•There is a lack of distinction between the different zirconia products.