Effect of Various Finishing and Polishing Environments on the Surface Roughness and Microleakage of Composite Restorations: An In Vitro Study.

Aim Finishing and polishing (FaP) are essential procedures that significantly affect the long-term clinical performance of composite restorations; however, their efficacy under varying environmental conditions remains insufficiently elucidated. This study aims to evaluate the impact of dry, wet, and combined FaP sequences on surface roughness (Ra) and microleakage of composite restorations.

Materials and methods A total of 57 premolars were randomly assigned to five groups: Control (Cg, n = 11), dry (Dg, n = 12), wet (Wg, n = 12), dry-followed-by-wet (DfWg, n = 11), and wet-followed-by-dry (WfDg, n = 11) group. Finishing was performed in all except Cg using a specified four-step sequence, i.e., fine diamond bur, white stone, and fine and extra-fine Sof-Lex discs. Surface roughness was measured using a profilometer, while dual microleakage evaluation was performed by recording microleakage scores (Ms) under a stereomicroscope (40×), and actual microleakage depths (Md) using a Tool Maker's microscope (30×).

Results Statistical analysis was conducted using the Kruskal-Wallis and Mann-Whitney tests. Intergroup comparisons revealed no significant differences in Ra values (p = 0.136). However, statistically significant differences were observed in Ms and Md values along both the occlusal (p = 0.002) and gingival margins (p = 0.000). Pairwise comparisons showed significantly smoother surfaces in Wg vs Dg (p = 0.04), with additional significant differences in microleakage between Cg-Dg, Cg-DfWg (both margins), and Wg-DfWg (gingival margin).

Conclusion The finishing of composite restorations under wet environmental conditions is somewhat beneficial with respect to surface roughness and microleakage.

Clinical significance This study describes the use of a standardized approach to assess the influence of varied environmental conditions on FaP outcomes. The findings provide clinically relevant insights that may further improve procedural efficiency, optimize surface quality, and enhance the longevity of composite restorations.