Effects of Polishing versus Glazing on Dental Ceramic Wear: A Comparative In Vitro Study

This study analyzed the wear behavior caused by steatite antagonists to four dental ceramic materials, comparing this between two surface treatments: polishing and glazing. Methods: Thirty flat samples (10 × 8 × 2 mm) were prepared from each of four ceramics: IPS e. max CAD (IPS), GC Initial LiSi Press (LP), Vita Enamic (VE), and monolithic zirconia (MZ). Subgroups of samples were finished by polishing or glazing or neither (as controls). The samples were subjected to computer-controlled chewing simulation (240,000 cycles of 49 N at 1.6 Hz, with thermocycling at 5/55 C), with steatite balls as antagonists. The samples and antagonists were visualized before and after the test with a laser abrasion measurement system, a CAD/CAM scanner, and electron microscopy scanning, and the volumes lost from the tested samples and antagonists were analyzed. Results: For the MZ samples, the polished samples showed significantly less volume loss than the glazed samples (0.0200 mm³ vs. 0.0305 mm³; p =0.0001), whereas there was significantly greater antagonist volume loss (0.0365 mm³ vs. 0.0240 mm³; p = 0.011). There were no significant differences between the subgroups for IPS, VE, and LP, although antagonist volume losses were non-significantly greater with the glazed samples than with the polished samples. Conclusions: Polishing MZ had adverse effects on the corresponding antagonist wear. Glazed MZ showed the lowest antagonist wear.