Effectiveness of ceramics chair-side polishing – 2D and 3D roughness evaluation

Abstract

Objectives: Considering the need for intraoral polishing of zirconia restorations, this in vitro study aimed to 1) evaluate the 2D and 3D surface roughness of different types of ceramic after their finishing and polishing and 2) compare three polishing techniques using three different polishing kits. Methods: Seventy-two specimens were obtained from two types of 3Y-TZP zirconia. After sintering, a layer of a glass-based fluorapatite veneering ceramic was applied over 24 specimens of one of the zirconia ceramics. Thus, three ceramic surfaces were set: Prettau Anterior, Prettau Zirconia, and IPS e.max Ceram. The specimens were polished with a universal or specific polishing kit (n=12). After polishing, the specimens were analyzed using white-light interferometry. Kruskal-Wallis and Mann-Whitney U tests were used (α=0.05). Results: The polishing kit used did not significantly (p=0.514) affect the surface roughness of Prettau Anterior. Regarding Prettau Zirconia, the zirconia-specific polishing kit allowed a higher Sa and Ra than the universal kit (p=0.004 and p<0.001). Regarding glass-based ceram- ic, the specific kit led to a higher Ra (p<0.001), but no significant results were found in 3D. Conclusions: The universal polishing set showed the best results for Prettau Zirconia and glass-based ceramic, but no differences were found for Prettau Anterior.