Effect of Finishing/Polishing Techniques on Surface Roughness of Three Different Resin Composite Materials: A laboratory Study

Objective: To determine the changes in surface roughness of different resin based composite materials having spherical shaped fillers after finishing and polishing with different systems and various application steps either one, two or three-steps. Materials and Methods: A total of 120 disc-shaped specimens (10 mm diameter × 2 mm thickness) were prepared from three different RBC materials (n=40 discs/group): a Nano-fill resin composite (Omnichroma); a Nano-ceramic resin composite (Neo Spectra ST) and a Nano-hybrid resin composite (Charisma Topaz). Each group was subdivided into four subgroups (n=10) according to the finishing/polishing (F/P) system: control (without F/P), one-step system (Enhance); two-step system (Super Snap Rainbow); and three-step system (Soflex). The mean Ra was measured using the profilometer. To compare the surface roughness between RBC materials without and after F/P, the collected data were subjected to statistical analysis using two-way analysis of variance (ANOVA), Student’s t-test and One-way ANOVA with Tukey’s post hoc tests. The level of significance was seated p<0.05. Results: The Nano-fill resin composite showed the lowest mean Ra while the Nano-ceramic resin composite showed the highest value. A statistically significant difference was found in Ra and without and after F/P for the three RBC materials (p<0.001). Conclusions: The various finishing and polishing systems had a noticeable effect on the surface roughness of the RBCs. The Nano-fill resin composite had the lowest surface roughness. The two-step F/P system provided the best F/P protocol of resin based composites evaluated.