RESUMO
AIM: To validate an in vitro caries model and to evaluate an experimental mouthwash containing Croton doctoris essential oil. Materials & methods: To validate the experimental model, we used McBain medium and polymicrobial biofilms. The EOM (essential oil mouthwash) was tested using the validated model. Microbial composition (colony-forming unit/ml), acidogenicity, enamel demineralization (percentage of surface enamel hardness loss), cytotoxicity and essential oil composition were evaluated. RESULTS: The model was validated with 0.5% sucrose, duration of 4 days and treatments twice per day. There were statistically significant differences between the EOM, the negative control and chlorhexidine mouthwash in colony-forming unit/ml and percentage of surface enamel hardness loss. Cytotoxicity was similar to that of chlorhexidine mouthwash. A total of 66.11% of the essential oil consists of sesquiterpenes. CONCLUSION: The experimental mouthwash showed antimicrobial activity against polymicrobial biofilms and reduced enamel demineralization.