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

Abstract

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.
Key Words: Lactobacillus plantarum, Mouthrinse, Probiotic, Streptococcus mutans