The effect of contemporary finishing and polishing systems on the surface roughness of bulk fill resin composite and nanocomposites.

OBJECTIVE: To evaluate the effects of various finishing and polishing (F/P) systems regarding the surface roughness (R(a) ) value of two nanocomposites and a bulk fill resin composite. METHODS AND MATERIALS: Three resin composites (Filtek Z550, Filtek Ultimate Body, Filtek Bulk Fill Posterior) were tested. Forty disk-shaped specimens of each material were cured under Mylar strip and then randomly divided into four subgroups according to the F/P method (n = 10): Control, Sof-Lex Spiral Wheels, Astropol, and Clearfil Twist Dia. R(a) values was measured and the surfaces were examined under scanning electron microscope. The data were analyzed by generalized linear models (p < 0.05). RESULTS: The Filtek Bulk Fill Posterior had the highest R(a) value while Filtek Ultimate Body was the resin composite with the lowest roughness (p < 0.05). Considering the average R(a) values after polishing, while the lowest R(a) in all groups was obtained with the control group, the Clearfil Twist Dia showed similar R(a) to the control group (p > 0.05). The samples polished with Sof-Lex Spiral Wheels had the highest R(a) (p < 0.05). CONCLUSIONS: In addition to the resin composite type, the F/P technique greatly affected the R(a) value of resin composite. The nanocomposites exhibited with the lowest R(a) compared to the bulk fill resin composite after F/P. It was observed that the diamond containing-polishing system created smoother surfaces than the aluminum oxide containing- and silicon carbide containing-polishing systems. CLINICAL SIGNIFICANCE: In terms of R(a) , the nanocomposites exhibited better performance than the bulk fill resin composites. Nowadays, newly developed polishing systems containing diamonds can be successful at a comparable level to existing polishing systems. For this reason, these systems are preferable for polishing both nanocomposites and bulk fill resin composites.