Effect of Finishing and Polishing on The Surface Roughness of Bulk Fill Composites

The aim of this in vitro study was to compare the effect of three finishing/polishing systems on the surface roughness (Ra) of conventional and Bulk-fill composite resins.

The Ra values of three different brands of Bulk-fill composites (Filtek Bulk-fill^®, 3M ESPE; SonicFill Bulk-fill^®, Kerr; SDR Bulk-fill^®, Dentsply) were tested and compared with the Ra of a conventional composite (Filtek XT Z350^®, 3M ESPE). A total of 30 discs (10 mm × 2 mm) were fabricated from four test materials and divided into three groups (n = 10/group) depending on the three finishing/polishing systems used (Astropol^®, Ivoclar Vivadent; PoGo^®, Dentsply; Sof-LexTM^®, 3M ESPE). The Ra of each specimen was recorded with an optical profilometer (Contour-GT-X^®, USA). ANOVA and Tukey’s tests were used for statistical analysis.

Statistically significant differences (P < 0.05) were observed between the Ra values of all composite materials tested with three finishing/polishing systems. Among composite materials, only Group-III showed a significant difference (P = 0.003) in Ra obtained using all three finishing/polishing systems. SDR Bulk-fill^® and Filtek XT Z350^® showed the highest (0.810 ± 0.373 µm) and lowest (0.365 ± 0.119 µm) Ra values, respectively. Individually, the highest Ra was recorded for SDR Bulk-fill^® when it was finished/polished with the Astropol^® system. SonicFill Bulk-fill^® and SDR Bulk-fill^® composites exhibited the lowest Ra values when they were finished with the PoGo^® system.

Finishing and polishing techniques greatly affect the surface roughness of different Bulk-fill composites because variations in the surface roughness were observed for all tested composite materials. Filtek XT Z350^® exhibited the lowest surface roughness, while SDR Bulk-fill^® exhibited the highest surface roughness among the tested composite materials.