Effects of different surface finishing protocols for zirconia on surface roughness and bacterial biofilm formation
- Author:
Du Hyeong LEE
1
;
Hang Nga MAI
;
Phyu Pwint THANT
;
Su Hyung HONG
;
Jaewon KIM
;
Seung Mi JEONG
;
Keun Woo LEE
Author Information
- Publication Type:Original Article
- Keywords: Zirconia; Dental finishing; Dental polishing; Biofilm; Bacterial adhesion
- MeSH: Bacterial Adhesion; Biofilms; Dental Instruments; Dental Polishing; Diamond; Silicon; Silicones; Streptococcus mutans
- From:The Journal of Advanced Prosthodontics 2019;11(1):41-47
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: Surface finishing of a zirconia restoration is essential after clinical adjustment. Herein, we investigated the effects of a surface finishing protocol for monolithic zirconia on final roughness and bacterial adherence. MATERIALS AND METHODS: Forty-eight disk-shaped monolithic zirconia specimens were fabricated and divided into four groups (n = 12) based on initial surface treatment, finishing, and polishing protocols: diamond bur+polishing bur (DP group), diamond bur+stone grinding bur+polishing bur (DSP group), no diamond bur+polishing bur (NP group), and no diamond bur+stone grinding bur+polishing bur (NSP group). Initial and final surface roughness was measured with a profilometer, and shown using scanning electron microscope. Bacterial adhesion was evaluated by quantifying Streptococcus mutans in the biofilm. Kruskal-Wallis and Mann-Whitney U tests were used to compare results among groups, and two-way analysis of variance was used to evaluate the effects of grinding burs on final roughness (α=.05). RESULTS: The DP group had the highest final Ra value, followed by the DSP, NP, and NSP groups. Use of the stone grinding bur as a coarse-finishing step significantly decreased final Ra values when a diamond bur was used (P < .001). Omission of the stone grinding bur increased biofilm formation on specimen surfaces. Combining a stone grinding bur with silicone polishing burs produced the smallest final biofilm values, regardless of the use of a diamond bur in initial surface treatment. CONCLUSION: Coarse finishing of monolithic zirconia with a stone grinding bur significantly decreased final Ra values and bacterial biofilm formation when surfaces had been roughened by a diamond bur.
