Resveratrol alters oral biofilm in vitro and in vivo

Objective: To evaluate the ability of resveratrol to reduce dental caries in vitro and in vivo. Methods: In part 1, a microcosm biofilm protocol was employed. One hundred twenty-six bovine enamel specimens were treated with: Resveratrol (50, 100, 200, 400 µg/mL), Phosphate buffered saline (negative control), Dimethyl sulfoxide (negative control) and 0.12% Chlorhexidine (positive control). The biofilm was produced from the saliva of 10 volunteers, under 0.2% sucrose exposure for 5 days, and daily treated with the solutions (1 min). At the end of the experimental period, resazurin and viable plate count assays were performed. Enamel demineralization was evaluated by transverse microrradiography (TMR). In part 2, 12 volunteers participated in a triple-blind crossover protocol for 7 weeks, according to the following treatments: 1) 100 mg/L resveratrol; 2) 0.05% NaF (226 mg/L F); 3) 100 mg/L resveratrol + 0.05% NaF; 4) Deionized water (negative control). Biofilm samples were collected from both sides of the mouth 12 h after the use of the solutions. Results: Resveratrol at 50 and 200 µg/mL significantly reduced biofilm metabolic activity and mutans streptococci, respectively. Chlorhexidine was an effective treatment to significantly reduce all parameters, being an important antimicrobial and anticaries agent in vitro. Resveratrol alone or associated with NaF modulated several caries-associated bacteria in vivo. Conclusion: The present study represents the first step regarding the use of resveratrol within the concept of acquired enamel pellicle and biofilm engineering to prevent dental caries.