IADR Abstract Archives
Effect Of Polishing Systems On Surface Roughness Of Monolithic Zirconia
Objectives: To evaluate the effect of different chairside polishing systems on the surface roughness and topography of monolithic zirconia.
Methods: Thirty-five monolithic zirconia specimens (Lava PLUS, 3M-ESPE) were fabricated, ranked, sequentially divided into five groups (n=7) and polished with the following: Group 1 (WZ) - Dura white stone followed by Shofu zirconia polishing kit; Group 2 (SZ) - Shofu zirconia polishing kit; Group 3 (CE) - Ceramiste polishing kit; Group 4 (CM) - Ceramaster polishing kit; Group 5 (KZ) - Komet ZR polishers. All specimens were ground with fine-grit diamond bur prior to polishing procedures to simulate clinical finishing. Baseline and post-polishing profilometric readings were recorded and delta Ra values (difference in mean surface roughness before and after polishing) were computed and analysed using one-way ANOVA and Scheffe’s post-hoc test (p<0.05). Representative SEM images of the ground but unpolished and polished specimens were acquired.
Results: The polishing systems smoothened ground zirconia to different extents. Delta Ra values ranged from 0.146 for CE to 0.400 for KZ. Delta Ra values for KZ, WZ and SZ were significantly greater than for CE. Significant difference in Delta Ra values were also observed between KZ and CM. The SEM images showed sporadic deep flaws resulting from grinding beneath the polished surfaces of some specimens.
Conclusions: Diamond-impregnated silicone polishing systems were more effective than silica carbide-impregnated ones in reducing the surface roughness of ground monolithic zirconia. Some differences in polishing effectiveness were, however, observed between the diamond-impregnated products.
Methods: Thirty-five monolithic zirconia specimens (Lava PLUS, 3M-ESPE) were fabricated, ranked, sequentially divided into five groups (n=7) and polished with the following: Group 1 (WZ) - Dura white stone followed by Shofu zirconia polishing kit; Group 2 (SZ) - Shofu zirconia polishing kit; Group 3 (CE) - Ceramiste polishing kit; Group 4 (CM) - Ceramaster polishing kit; Group 5 (KZ) - Komet ZR polishers. All specimens were ground with fine-grit diamond bur prior to polishing procedures to simulate clinical finishing. Baseline and post-polishing profilometric readings were recorded and delta Ra values (difference in mean surface roughness before and after polishing) were computed and analysed using one-way ANOVA and Scheffe’s post-hoc test (p<0.05). Representative SEM images of the ground but unpolished and polished specimens were acquired.
Results: The polishing systems smoothened ground zirconia to different extents. Delta Ra values ranged from 0.146 for CE to 0.400 for KZ. Delta Ra values for KZ, WZ and SZ were significantly greater than for CE. Significant difference in Delta Ra values were also observed between KZ and CM. The SEM images showed sporadic deep flaws resulting from grinding beneath the polished surfaces of some specimens.
Conclusions: Diamond-impregnated silicone polishing systems were more effective than silica carbide-impregnated ones in reducing the surface roughness of ground monolithic zirconia. Some differences in polishing effectiveness were, however, observed between the diamond-impregnated products.