Evaluation of Surface Roughness of Different Direct Resin-based Composites

AIMS AND OBJECTIVE: To evaluate surface roughness of different resin-based composites. MATERIALS AND METHODS: Three resin composites, one nanohybrid, one nanoceramic, and one bulk-fill resin-based composite, were used in this study. Cylindrical Teflon mold and 8 mm in diameter and 2 mm in thickness disc specimens were prepared. For each composite material, 15 discs were fabricated, with a total of sixty discs were obtained (n = 60). A glass slide 1–2 mm thick was placed over the strip before curing with the light-curing unit to flatten the surfaces. The specimens were then cured for 40 s through the Mylar strip and the glass slide. Five specimens per each material received no finishing treatment after being cured under Mylar strips; these specimens served as a control. Ten specimens from each composite material were finished/polished with Eve discs at coarse, medium, fine, and superfine grits for 30 s (using stopwatch) each on the specimens. After polishing, the composite surfaces were assessed quantitatively by profilometry and qualitatively by scanning electron microscopy. Data were analyzed using SPSS software. RESULTS: Tetric Evo Ceram and Tetric Evo Ceram Bulk-Fill specimens polished with Eve revealed slightly the same surface appearance as the Mylar strip. Eve discs scratched and exposed fillers of Ceram-x. Eve discs for Z250 surfaces exposed and scratched the filler particles but less than occurred with Ceram-x. CONCLUSION: Bulk-Fill and nanohybrid resin composites exhibit smoothest surfaces compared with nanoceramic and microhybrid resin composites after polishing.