The effect of different polishing methods on the surface roughness of two scalpel finished resin composites

Abstract

Aim: to evaluate the effect of different polishing methods on the surface roughness (Ra) of two scalpel finished resin composites. Materials and Methods: Seventy two resin composite discs were prepared and cured against Mylar strip and divided into two groups (n=36) according to type of resin composite material, Group A1 (nano filled) and Group A2 (nano hybrid). Except for the control group (B0), samples were finished with scalpel blade, then divided into 5 subgroups (n=6) according to the polishing method, subgroup B1 (scalpel finished only and not followed by polishing), subgroup B2 (Sof-Lex Extra Thin Polishing discs), subgroup B3 (Sof-Lex Spiral wheels), subgroup B4 (Sof-Lex polishing strips) and subgroup B5 (polishing paste and brush). Samples were scanned using SEM, scans were analyzed by Gwyddion 2.59 Image Analysis Software to attain surface roughness average Ra data, which were statistically analyzed by two-way ANOVA and Turkey Post Hoc test. Results: There was a significant interaction between the resin composite material and the polishing protocol. Nano hybrid A2 had a significantly higher value than nano filled A1. And between the different finishing and polishing methods, there was a significant difference between different groups. The highest value was found in B1, followed by B4, then B2, B0 and B5, while the lowest value was found in B3. Conclusion: Scalpel is a good finishing tool for resin composite to produce a smoother micro surface ready for polishing. Nano filled resin composite produces a smoother surface than nano hybrid resin composite with different polishing methods.