Effect of finishing and polishing procedures on biofilm adhesion to composite surfaces: An ex vivo study

Abstract

Introduction: Surface roughness allows plaque accumulation resulting in gingival inflammation, superficial staining and secondary caries. Proper surface finishing and polishing are critical clinical procedures which enhance esthetics and longevity of restorations. This study evaluated adhesion of Streptococcus mutans biofilm on the surface of composite resin discs (nanofilled, Filtek Z350, 3M ESPE, Salt Lake City, UT, USA) after finishing and polishing by different techniques. Methodology: Sixty samples of nanofilled composite resin were prepared in a circular shaped disc- 6 mm × 2 mm and divided randomly in three groups (n = 20) for surface treatments. Control group: composite resin surface in contact with Mylar matrix strips with no finishing or polishing performed, Sof-Lex aluminum oxide disc technique and 30-blade tungsten carbide burs and silicon carbide brushes, Astrobrush. The samples were subjected to biofilm adhesion by inoculation in suitable media. The response variable was the mean CFU/mL present in the Streptococcus mutans biofilms formed on the composite resin surface. Data was statistically analyzed by three-way analysis of variance (ANOVA). Results: The Mean adhesion found in Mylar matrix strip group at 10 dilution was 74.7 ± 3.5, in Sof-Lex group was 147.3 ± 7.0 and in Astrobrush group was 149.4 ± 8.1. This difference in the mean values between the groups was found to be statistically significant (p < 0.01). Conclusion: Mylar matrix strips promoted the least bacterial adhesion, polishing with Sof-Lex aluminium oxide discs provided a smoother surface than Astrobrush and hence less bacterial adhesion than Astrobrush system.