Effect of Different Polishing Systems on the Surface Roughness and Gloss of Novel Nanohybrid Resin Composites

Objectives To evaluate the surface roughness and gloss of three nanohybrid resin composites after polishing with three different polishing systems. Materials and Methods A total number of 112 disc specimens (10 × 3 mm) were prepared from nanohybrid—Empress Direct (ID), Grandio (GR), Filtek Z350 (Z350) and a microhybrid resin composite restorative materials—Filtek Z250 (Z250). Following 24-hour storage in 37°C distilled water, each composite group ( n = 28) was assigned into four groups ( n = 7) according to finishing/polishing (F/P) system: Mylar strip, Optrapol, Politip, and Sof-Lex (SL). The surface roughness (Ra, mm) was measured by a novel three-dimensional method using an image analysis software attached to an environmental scanning electron microscope. A glossometer was used to measure the surface gloss. Results Statistical analysis used was ANOVA test. Two-way Anova test revealed that the “type of composite” and “F/P techniques” had a significant effect on both surface roughness and gloss of the tested resin composite materials ( p < 0.05). Tukey’s post hoc test showed that ID, GR, and Z350 revealed lower surface roughness and higher surface gloss than Z250 within the same polishing system ( p < 0.05). Sof-Lex polishing discs produced the lowest surface roughness and highest surface gloss values compared with Optrapol and Politip ( p < 0.05). Conclusion The tested F/P systems provided comparable surface roughness and gloss for nanohybrid composites. The Sof-Lex system provided the best surface roughness and gloss for nanohybrid composites.