Antimicrobial Effects of Mass and Oral-B Mouthwashes on Streptococcus mutans and Candida albicans: An In Vitro Study

The present study aimed to compare the antimicrobial properties of Iranian Mass mouthwash and alcohol-free Oral-B mouthwash against Streptococcus mutans (S. mutans) and Candida albicans (C. albicans). Methods In this in vitro study, S. mutans and C. albicans were separately cultured on BHI agar plates. The agar well-diffusion method was used to compare the antimicrobial properties of Mass and Oral-B mouthwashes, and 0.2% chlorhexidine (CHX) as the positive control and saline as the negative control. The diameter of growth inhibition zones was then measured. The experiment was performed in triplicate. The minimum inhibitory concentration (MIC), and the minimum bactericidal concentration (MBC) of the two mouthwashes were determined for each microorganism using the broth micro-dilution method. Data were analyzed by the Kruskal-Wallis and Dunn's test (Benjamini-Hochberg). Results The mean diameter of the growth inhibition zone of S. mutans was 26.33 and 27.66 mm for Mass and Oral-B mouthwashes, respectively. These values were 18 mm and 17.66 mm, respectively for C. albicans. There was no significant difference in the mean diameter of growth inhibition zones of the two mouthwashes against C. albicans (P=0.38) or S. mutans (P=0.23). The MIC of Mass and Oral-B mouthwash for S mutans was in 1/1024 dilution ratio and the MIC of Mass and Oral-B mouthwashes for C. albicans was in 1/512 and 1/256 dilution ratios, respectively. The MBC values were the same as the MIC values for both mouthwashes. Conclusion Mass mouthwash was as effective as Oral-B mouthwash against S. mutans and C. albicans.