Comparison of different finishing/polishing systems on surface roughness and gloss of resin composites

Objectives: The aim of this study was to compare four finishing/polishing systems (F/P) on surface roughness and gloss of different resin composites. Methods: A total of 40 disc samples (15 mm × 3 mm) were prepared from a nanofill - Filtek Supreme Plus (FS) and a micro-hybrid resin composite - Esthet-X (EX). Following 24 h storage in 37 °C water, the top surfaces of each sample were roughened using 120-grit sandpaper. Baseline measurements of surface roughness (Ra, μm) and gloss were recorded. Each composite group was divided into four F/P disk groups: Astropol[AP], Enhance/PoGo[EP], Sof-Lex[SL], and an experimental disk system, EXL-695[EXL] (n = 5). The same operator finished/polished all samples. One sample from each group was evaluated under SEM. Another blinded-operator conducted postoperative measurements. Results were analysed by two-way ANOVA, two interactive MANOVA and Tukey's t-test (p < 0.05). Results: In surface roughness, the baseline of two composites differed significantly from each other whereas postoperatively there was no significance. The Sof-Lex F/P system provided the smoothest surface although there were no statistical significance differences between F/P systems (p > 0.01). In gloss, FS composite with the EXL-695 system provided a significantly higher gloss (p < 0.01). EX treated by Soflex revealed the least gloss (p < 0.05). SEM images revealed comparable results for F/P systems but EX surfaces included more air pockets. Conclusions: Four different finishing/polishing systems provided comparable surface smoothness for both composites, whereas EXL with FS provided significantly higher gloss. SEM evaluations revealed that the EX surface contained more air pockets but F/P systems were compatible.