Effect of Polishing on Surface Roughness of Nanofilled Resin Composite

Objective: To evaluate the effect of different polishing instruments on surface roughness of nanofilled resin-composite. Materials and methods: Resin-composite (Filtek Z350®, 3M-ESPE) was condensed in 5×4×2 mm3 block covered with Mylar strip and then polymerized with curing unit for 40 s. Resin-composite specimens were randomly divided into 6 groups equally. The first group was a control. The other groups were polished with Sof-Lex® (3M-ESPE), Enhance® (Dentsply), Pogo® (Dentsply), Composhape® (Intensiv) and Jet bur® (Kerr). The average surface roughness (Ra) was measured with a profilometer after polishing for 40 s, following manufacturer's instruction. Surface topography was observed using a scanning electron microscope (SEM) from samples of each group. Data were analyzed by one-way ANOVA, at p<0.05. Results: The smoothest surfaces were produced with Sof-Lex® (0.0164±0.008µm) which were not statistically different from the control group (0.0156±0.0092µm). However, polished with Pogo® (0.0641±0.0601µm), Enhance® (0.1801±0.0839µm), Composhape® (0.1839±0.0732µm) and Jet bur® (0.2626±0.1112µm) showed a statistically higher Ra value than the control group, respectively (p<0.05). Among the experimental groups, they all showed statistical differences except between the Enhance® and Composhape® groups. The results from SEM supported the Ra value. Conclusions: Nanofilled resin-composite displayed variable roughness depending on the polishing instruments used; Sof-Lex® gave the best polished surface.