Evaluation of the effects of fluoride mouth rinse and varnish on the early biofilm formation of Streptococcus mutans in two types of orthodontic adhesive resins: An in vitro study

BACKGROUND: The aim of the present study is to compare the antibacterial effect of fluoride mouth rinse and fluoride varnish on the primary biofilm formation of Streptococcus mutans (S. mutans) in two types of orthodontic adhesives. MATERIALS AND METHODS: This is an in vitro study in which forty composite discs of Transbond XT and Lightbond were divided randomly into 4 groups: Group 1: Control group (not treated with fluoride), Group 2: Rinsed by 0.2% fluoride mouth rinse, Group 3: Rinsed by 0.05% fluoride mouth rinse, and Group 4: Treated by varnish fluoride. Then each group was placed in S. mutans suspension. Bacterial suspension from each treatment was subcultured onto the surface of Mueller–Hinton agar plates, and bacterial growth was assessed. The results were analyzed by analysis of variance test and Scheffé test was run to compute the binary groups (P < 0.05). RESULTS: There was a statistically significant reduction in the viability of S. mutans in treated groups by fluoride but no significant difference between two types of composites. CONCLUSION: The results of this study demonstrated that S. mutans colonies were sensitive to fluoride and their most effective form was varnish. There was no significant difference in early biofilm formation of S. mutans in two types of orthodontic adhesive resins Transbond XT and Lightbond.