Comparison of the antibacterial effect of nanosilver and chlorhexidine mouthwash on Streptococcus mutans (invitro)

Background: Many bacteria are involved in dental plaque formation and caries. Streptococcus mutans is one of the most important bacteria involved in this case. One of the ways to control plaque is the use of mouthwash on the side of toothbrushes and toothbrushes. Although chlorhexidine is the most effective mouthwash against oral microorganisms, the side effects of long-term use suggest the need for an alternative. The purpose of this study was to compare the antibacterial effect of nanosilver and chlorhexidine mouthwash on Streptococcus mutans in pediatric ward of Dental School of Islamic Azad University of Tehran and Laboratory of Veterinary School of Tehran University in 1397-1398. Materials and methods: This experimental study was performed in vitro on Streptococcus mutans. Experiments were performed on two groups of case (nanosilver mouthwash) and control (chlorhexidine mouthwash) in three parts. Antimicrobial potency was measured by Disk diffusion assay by measuring inhibitory zone diameter. Then both micro and macro dilution methods were used to measure MIC (Minimum bacterial growth Inhibitor Concentration) and finally for measure MBC (Minimum Bactericidal Concentration) using Blood agar dilution method. Results : Statistical analysis showed that the nanosilver mouthwash has no inhibitory zone and MBC. Also its MIC was higher than chlorhexine and this difference was statistically significant (P <0.001). Conclusion: According to the results of the in vitro study of nanosilver mouthwash compared to chlorhexidine, it has minor bacteriostatic properties and no bactericidal effect. It is recommended to repeat this study by changing the mouthwash formulation in terms of particle concentration and diameter.