Abstract
Background: Many plants and natural products have strong antimicrobial activity in addition to their side effects. The present study evaluated the antibacterial effects of plant extracts of licorice, sage, and grape seeds on the proliferation of Streptococcus mutans (S. mutans) and enamel remineralization. Methods: After preparing the plant extracts, first, the antibacterial effect of each extract on S. mutans growth and proliferation was evaluated. Then 128 teeth with intact cusps were selected, prepared, and placed in a demineralizing solution for 10 weeks. Subsequently, their surface microhardness was determined. Finally, after randomly assigning the teeth to the plant extract groups, they were subjected to a pH cycling procedure for 14 days, and their surface microhardness was re-evaluated. Statistical analyses were conducted using Stata 14 at a 95% confidence interval. Results: All the studied plant extracts exhibited antimicrobial effects on S. mutans and increased the surface microhardness of the teeth. Generally, the differences in microhardness in each group and between the study groups were significant (P<0.001). Conclusions: According to the results, all the plant extracts had antibacterial effects on S. mutans and assisted in remineralizing dental caries by inhibiting this bacterial species.