Abrasivity of Yttria Tetragonal Zirconia Polycrystals Abrasivity of Yttria Tetragonal Zirconia Polycrystal (Y-TZP) to dental enamel in comparison to Noble White High Palladium alloy

Objectives: To test the wear of enamel against Yttria Tetragonal Zirconia Polycrystals (Y-TZP) in comparison to the wear of enamel against a noble white high Palladium alloy. Methods: A total of 20 specimens were used, 10 of Y-TZP and 10 of High Palladium alloy, both were subjected to 202,800 contacts against an enamel rod 2x2 mm in cross section under a mean load of 475.04g leading to a mean force of 4.66 N in a Wilson Wear Machine. The specimens were kept in Dulbecco’s phosphate buffered saline at a pH of 7 and the enamel rods were measured before and after the experiment for loss of enamel height (mm). Results The mean wear caused by the Y-TZP and the High Palladium alloy tested was 0.0912 mm, and 0.0113 mm respectively. This difference was statistically significant (p = 0.012 (p<0.05)). Significance It is recommended that Y-TZP is not to be used to form the occlusal surfaces of indirect restorations due to its high abrasive potential with respect to dental enamel.