Background: There are controversies regarding the most effective surface treatment method to be applied for the effective repair of resin composites.
Aims: This study aimed to compare the effects of surface roughening processes on repair bond strength of different types of aged composites. Water aging was applied to 60 nanohybrid and 60 micro-hybrid resin composite samples for 1 year. Samples were randomly divided into five groups and four types of roughening processes. Bur, OPTIDISC, SUPERSNAP, and BISCO were applied to the water-aged resin composite samples. Micro-shear test method was used to measure the repair bond strength.
Materials and methods: Data were analyzed with IBM SPSS V23. Compliance with normal distribution was examined by Kolmogorov-Smirnov test. Two-way analysis of variance (ANOVA) and Tukey HSD test for multiple comparisons were used.
Results: The main effect of the type of resin composites and surface roughening methods were found to be significantly different. The MPa values of surface roughening groups were similar while the lowest mean value was obtained for the untreated group of the nanohybrid resin composite (P < 0.001). The bond strength for both resin composites was generally considered within acceptable limits except for no treatment group of nanohybrid resin composite.
Conclusions: This study showed that surface roughening method is mandatory for effective bond strength and the type of fillers in resin composite affects the micro-shear bond strength.
Keywords: Bond strength; repair; resin composite; surface roughness; water aged.