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

Objectives: To evaluate the surface roughness and gloss of three nanohybrid resin composites after polishing with three different polishing systems.
Methods: A total number of 112 disc specimens (10×3 mm) were prepared from nanohybrid–Empress Direct (ID), Grandio (GR), Filtek Z550, (ZN) and a microhybrid resin composite restorative materials–Filtek Z250 (ZM). Following 24 h storage in 37°c distilled water, each composite group (n=28) was assigned into four groups (n=7) according to finishing/polishing system: Mylar strip {MS}, Optrapol {O}, Politip {P}, and Sof-Lex {SL}. The surface roughness (Ra, mm) was measured by a new novel 3D method using an image analysis software attached to Environmental Scanning Electron Microscope (ESEM). The surface gloss was measured by a glossometer.
Results: Two-way ANOVA test revealed that the ‘type of composite’ and ‘finishing/polishing techniques’ had significant effect on both surface roughness and gloss of the tested resin composite materials (p < 0.05). Tukey post hoc test showed that ID, GR and ZN revealed lower surface roughness and higher surface gloss than ZM within the same polishing system (p <0.05). Sof-Lex polishing discs produced the lowest surface roughness and highest surface gloss values compared to Optrapol and Politip (p < 0.05).
Conclusions: The tested finishing/polishing systems provided comparable surface roughness and gloss for nanohybrid composites, whereas SL system provided the best surface roughness and gloss for nanohybrid composites.