A comparison of polishing systems and thermal cycling on the surface roughness and color stability of a single-shade resin composite.

Purpose: To evaluate the surface roughness and color stability of a single-shade composite resin after thermal cycling with different finishing and polishing systems.

Methods: A total of 91 specimens were prepared with standard molds using a single-shade resin composite Omnichroma. The specimens were randomly separated into seven groups: Control (Mylar strip only), grit (600 grit SiC abrasive paper), OneGloss, Clearfil Twist Dia, Sof-Lex Diamond Polishing System, EVE Diacomp Plus Twist, and OptiDisc. The top surface of each specimen was polished per the manufacturers' directions. After initial measurements, 10,000 and 50,000 thermal cycles were performed. After each thermal cycling, the measurements were retaken. A generalized linear model analysis was used to compare the values, and multiple comparisons were performed with the Bonferroni correction.

Results: Different finishing and polishing systems and thermal cycling significantly affected the surface roughness and color change of the single-shade composite resin (P< 0.001). The smoothest surfaces were obtained with the Sof-Lex Diamond Polishing System, while the group polished with Clearfil Twist Dia showed the least color change.

Clinical significance: The surface roughness of the single-shade resin composite exhibited acceptable values for all polishing systems tested. The color change values of the single-shade resin composite were found to be above the acceptable value for all polishing systems, but the two-step spiral polishing systems performed better in terms of color stability.