Effects of probiotic and fluoride mouthrinses on Streptococcus mutans in dental plaque around orthodontic brackets: A preliminary explorative randomized placebo-controlled clinical trial

BACKGROUND: Although it is shown that probiotic agents might reduce Streptococcus mutans, no study has evaluated this effect in the form of probiotic mouthrinse. The purpose of this study was to compare the effect of probiotic experimental mouthwash Lactobacillus plantarum versus sodium fluoride and placebo mouthwashes on the number of S. mutans present in dental plaque around orthodontic brackets in fixed orthodontic patients. MATERIALS AND METHODS: This study was a randomized clinical trial. The total of 38 patients participate consisting of 12 patients in the fluoride group, 13 in the probiotic, and 12 in the placebo group. They were given mouthwashes to use twice a day for 2 weeks. Plaque sampling was performed using the 4-pass technique in all three groups in two stages: before the intervention and after 2 weeks of using the mouthwash. The number of bacteria present in the dental plaque was then reported based on the number of colonies grown on agar medium. Data were analyzed using Kruskal–Wallis and Wilcoxon tests (α = 0.05). RESULTS: Gender distribution, mean age, and protocol adherence were not significantly different among all three groups. After the intervention, the number of S. mutans present in the dental plaque followed an increasing manner in the placebo (P = 0.005) and probiotic (P = 0.158) groups and decreased in fluoride group (P = 0.025). CONCLUSION: The L. plantarum probiotic mouthwash was ineffective in reduction of S. mutans in dental plaque. However, fluoride mouthwash is considerably effective against S. mutans and thus recommended.