Anti-microbial efficacy of Allium sativum extract against Enterococcus faecalis biofilm and its penetration into the root dentin: An in vitro study

Introduction: Sodium hypochlorite (NaOCl) has long been the most preferred root canal irrigant in endodontic treatment, but besides being an effective anti-microbial agent, it is highly cytotoxic. Thus, a search for an alternative herbal irrigant which would be more biocompatible but equally effective led to this study. Aim: To assess the anti-microbial efficacy of garlic extract (GE) against Enterococcus faecalis biofilm and its ability to penetrate into root dentin. Materials and Methods: E. faecalis was cultured and treated with the test agents - normal saline, 5.25% of NaOCl, and the three different concentrations of GE (10%, 40%, and 70%). The experiment was done in four groups namely, 24-h Co-treatment group, 24-h biofilm treatment group, 1-week biofilm group, and 3-week biofilm group. These groups were subjected to microbial viability assay and fluorescence microscopic analysis. The most effective concentration of garlic (70%) was further tested and compared with 5.25% NaOCl for its dentin penetration property using 0.2% alizarin red under a fluorescence microscope. Results: The findings revealed that GE was able to disrupt as well as prevent the formation of biofilm produced by E. faecalis. All the concentrations of GE displayed considerable anti-microbial efficacy where 70% concentration was most effective and exhibited similar anti-microbial efficacy as 5.25% NaOCl. In terms of dentin penetration, no significant difference was found between GE and NaOCl. Conclusion: The results indicate that GE has a potential to serve as an alternative herbal root canal irrigant being an effective and biocompatible anti-microbial agent with good dentinal penetration property.