An in vitro microbial model for producing caries-like lesions on enamel

This study aimed to develop a low cost in vitro viable microbiological model to produce biofilms to be used in dental researches. Single and multi-species biofilms of S. mutans, S. sobrinus, S. mitis, S. salivarius, S. cricetus and S. sanguinis were grown on bovine enamel slabs during 10 days, in a sterile brain-heart infusion broth, containing 5% sucrose and incubated at 37°C in an atmosphere of 10% CO₂. The slabs were transferred to a fresh medium at every 6, 12 or 24 hours. After the experimental period, enamel volume percent mineral was determined by cross-sectional microhardness. Caries-like lesions were found in all bacterial groups when compared with the control group. No statistical significant differences were found between S. mutans and S. sobrinus with respect of their cariogenicity or among the periods of medium change. However, it was found a statistical significant difference among the cariogenicity of S. salivarius and S. sanguinis (ANOVA followed by Tukey test). This model has successfully developed caries-like lesion on enamel and the medium can be changed at every 24 hours utilizing either S. mutans or S. sobrinus.