IADR Abstract Archives
A study on topographical properties and surface wettability of monolithic zirconia after use of diverse polishing instruments with different surface coatings
Objectives: Improper surface finishing of fixed dental prosthesis (FDP) made of monolithic zirconia (MZ) may cause opposing enamel wear. This study investigated the surface topography parameters and wettability of MZ using polishers with different coatings and sequences.
Methods: MZ specimens (N=50, n=10 per group) (Katana Zirconia HT) (12x12x1.8 mm3) were polished and randomly allocated to 5 groups, namely BG: Silicone carbide polishers (Brownie, Greenie, Super Greenie); CG: Diamond impregnated ceramic polisher (Ceragloss); EV: Synthetically bonded grinder interspersed with diamond (EVE Kit); SL: Urethane coated paper with aluminium oxide grits (Soflex Kit) and DB: Diamond bur (8 µm, FG9205/6). After roughening and baseline measurement, each polishing step was performed for 10 s. A custom made device (750 g load, 5.000-30.000 rpm) was produced for polishing procedures. Topographical changes were evaluated considering a) Weight (Digital scale), b) Volume loss (Digital microscope), c) Vertical height loss (Digital Microscope), d) Surface roughness (Profilometer) and e) Surface wettability (Goniometer). Data (5 levels: ∆W, ∆V, ∆VH, ∆Ra, ∆SW) for polishing regimens (BG, CG, EV, SL, DB) were analyzed using one-way ANOVA, post-hoc Scheffé and Wilcoxon tests. Correlation coefficients were calculated using regression analysis with linear correlation (alfa=0.05).
Results: Surface material loss after polishing compared to baseline (∆W) ranged between -3±0.1x10-4-296±8x10-4 g in ascending order as follows: SLaaabc, volume loss difference (∆V) -0.158±0.03x10-6-0.245±0.07x10-6 mm3 (SLaaa,bbc), vertical height loss (∆VH) -18.91±3.52-55.19±6.26 µm (SLaaa,bbc), surface roughness (∆Ra) -0.143±0.015-0.855±0.419 µm (DBaaaab) and contact angle (∆SW) -3.93±0.79°-2.79±3.14° (BGaaaaa).
Conclusions: All polishing instruments performed similar when ∆Ra values are considered, indicating that monolithic zirconia could not be polished ideally with the tested polishing regimens. After 40 s of polishing, SL, BG and CG performed similar, producing the least material loss of the MZ tested. Synthetically bonded rubber bur interspersed with diamond (EV) could not be suggested for polishing monolithic zirconia.
Methods: MZ specimens (N=50, n=10 per group) (Katana Zirconia HT) (12x12x1.8 mm3) were polished and randomly allocated to 5 groups, namely BG: Silicone carbide polishers (Brownie, Greenie, Super Greenie); CG: Diamond impregnated ceramic polisher (Ceragloss); EV: Synthetically bonded grinder interspersed with diamond (EVE Kit); SL: Urethane coated paper with aluminium oxide grits (Soflex Kit) and DB: Diamond bur (8 µm, FG9205/6). After roughening and baseline measurement, each polishing step was performed for 10 s. A custom made device (750 g load, 5.000-30.000 rpm) was produced for polishing procedures. Topographical changes were evaluated considering a) Weight (Digital scale), b) Volume loss (Digital microscope), c) Vertical height loss (Digital Microscope), d) Surface roughness (Profilometer) and e) Surface wettability (Goniometer). Data (5 levels: ∆W, ∆V, ∆VH, ∆Ra, ∆SW) for polishing regimens (BG, CG, EV, SL, DB) were analyzed using one-way ANOVA, post-hoc Scheffé and Wilcoxon tests. Correlation coefficients were calculated using regression analysis with linear correlation (alfa=0.05).
Results: Surface material loss after polishing compared to baseline (∆W) ranged between -3±0.1x10-4-296±8x10-4 g in ascending order as follows: SLa
Conclusions: All polishing instruments performed similar when ∆Ra values are considered, indicating that monolithic zirconia could not be polished ideally with the tested polishing regimens. After 40 s of polishing, SL, BG and CG performed similar, producing the least material loss of the MZ tested. Synthetically bonded rubber bur interspersed with diamond (EV) could not be suggested for polishing monolithic zirconia.