Evaluation of Antibacterial Properties of Resin Composites Containing Silver Nanoparticles on Streptococcus Mutans

Background and Objectives: Studies showed that resin composites are more susceptible to aggregation of biofilm than amalgam and glass ionomers and have lesser antibacterial effects which results in increasing the rate of secondary caries? Therefore, production of antibacterial resin composites was always under investigation. Thus, the aim of this study is evaluating the efficacy of resin composites containing silver nanoparticles against the Streptococcus Mutans. Methods:In this experimental study, the antibacterial properties of resin composites incorporating 0, 0/02, 0/03, 0/04, 0/05% w/w of Nano silver particles was investigated using turbidity test. Composites was formed on the walls of 400 ml micro plates and after the curing, they left in contact with bacterial suspension. In times of 3, 24 and 48 hours, the optical density of the broth was read by spectrophotometer. The data was analyzed by Kolmogorov-Smirnov, one-way ANOVA, LSD test and repeated measure ANOVA. Results: The results showed that all composites containing silver nanoparticles had antibacterial effects (p ≤0/05) and by increasing the amount of silver nanoparticles to 0/03% w/w, the anti-bactericidal effect rose and the bacterial growth significantly diminished (p=0/001). However, in higher concentrations than 0/03%, this effect decreased. The MBC (minimum bactericidal concentration) were seen in composites with 0/02 percent of silver nanoparticles. Conclusion: While all composite groups containing silver nanoparticles had antibacterial effect, the most efficient group was 0/03% w/w and by increasing the amount of silver nanoparticles over 0/04%, the antibacterial effect didn’t increase significantly