ABSTRACT
OBJECTIVE: To investigate the effect of toothbrushing on the surface roughness (Ra ) of different sealant agent coupled nanohybrid composite resins. MATERIALS AND METHODS: One hundred sixty disc-shaped (10 × 2 mm) specimens were prepared from four different nanohybrid composite resins (Z-550, Tetric EvoCeram, Clearfill Majesty, Ice). Specimen groups were divided into four subgroups for conventional polishing (control) and to apply three different surface sealant agents (Palaseal, Optiglaze, Biscover LV) (n = 10). The Ra values of the specimens were recorded before (Ra 0) and after 10,000 cycles of toothbrushing (Ra 1). The surface properties of the specimens were evaluated with scanning electron microscope (SEM). Data were statistically analyzed by two-way analysis of variance (ANOVA), Tukey HSD, and paired sample t tests. RESULTS: Composite resin material, surface treatment, and their interaction were significant on Ra values (p < 0.001). Significant decrease in Ra 0 values observed for surface sealant agent coupled Clearfill Majesty and Tetric EvoCeram composite resin groups compared with the control groups (p < 0.05). After simulated one-year toothbrushing, the control group of Clearfill Majesty had the highest Ra 1 value (p < 0.001). The Ra 1 values of all groups were significantly higher than the Ra 0 values (p < 0.05). CONCLUSIONS: Simulated 1-year toothbrushing increased the surface roughness of all nanohybrid composite resin materials. Optiglaze and Biscover LV sealant agents on Tetric EvoCeram, and all tested sealant agents on Clearfill Majesty enabled smoother surfaces than conventional polishing after toothbrushing. CLINICAL SIGNIFICANCE: Because toothbrushing increases the surface roughness of tested nanohybrid composite resins, the application of surface sealant agents on some of the tested resins can be considered for smoother surfaces.
