Antimicrobial effectiveness of aqueous and alcoholic herbal extracts on Streptococcus mutans: A systematic review and...

Debates about the efficacy of herbal products in oral care have inspired researchers to conduct a large number of trials. This systematic review and meta-analysis aimed to assess the antibacterial efficacy of aqueous and alcoholic herbal extracts against Streptococcus mutans (SM) as the main cariogenic microorganism.

Online databases PubMed, Scopus, Cochrane Library, Web of Science, and Magiran were searched for randomized controlled trials evaluating the efficacy of herbal products against SM published up to July 2023. Meta-analyses were performed for immediate and long-term effects based on random effect model.

Out of 57 studies that met the selection criteria for systematic review, 26 were subjected to meta-analysis. Considering both immediate and long-term effects on salivary SM, aqueous and alcoholic herbal extracts were significantly superior in the reduction of SM over non-herbal agents (immediate: SMD = -1.16; 95%CI: -2.03, -0.29, long-term: SMD = -0.76; 95%CI: -1.35, -0.17). However, the difference was not significant in the reduction of SM of plaque (SMD = -0.30, 95%CI: -1.25, 0.65). The subgroup analyses showed no significant difference compared to chlorhexidine (p>0.05). The overall quality of evidence was considered low based on GRADE tool.

Current evidence suggests encouraging results for herbal extracts in reduction of SM, but not over chlorhexidine. However, there is still insufficient evidence to recommend them as the first option for oral care. High-quality randomized controlled trials are required to assert the safety and effectiveness of them for preventing dental caries.