Effect of Various Finishing Systems on Surface Rougness of Low-Shrinking-Composite-Resin

Objective: This study evaluated the surface quality of a new low-shrinking resin material after polishing with seven different techniques. Methods: The composite resin used in this study was the experimental material, Hermes (3M.E.S.P.E). Seventy specimens, sized 9x5x3mm were prepared using perspex moulds. The upper and lower surfaces of the material was covered with Mylar strips(MS), which in turn was covered with glass slabs. The specimens were polymerized for 40 seconds on each side, the glass slab and mylar strips removed and then cured for an additional 40 seconds from each side. All samples were stored in distilled water for 10 days. Samples were randomly divided into 7 groups (n=10). Thereafter, the average roughness of one side of each specimen (formed against the matrix) was recorded using a Surftest SJ 301. The other side of each specimen was roughened with 320 grit silicone-carbide paper in a polishing machine for 45 seconds. The finishing/polishing of the specimens was performed following the five different protocols according to the manufacturer’s instructions: (1) Enhance polishing cones (E), (2) Enhance followed by POGO (EPG), (3)Ultradent (U), (4) consecutive use of four flexible Sof-Lex discs (S), (5) consecutive use of four flexible Sof-Lex discs followed by Sof-Lex Brushes(SB), (6) consecutive use of three flexible OptiDiscs (O), and (7) consecutive use of three flexible OptiDiscs followed by Optishine brushes (OB). The mean roughness of each polished surface was determined using suface profilometry, collecting 3 measurements from each specimen. Data was analyzed statistically (ANOVA). Results: Statistically significant differences in surface roughness were observed between Enhance compared to all the other groups (p<0.001). Conclusion: Most of the polishing systems tested in this study can be utilised for polishing Hermes composite resin.