A comparative evaluation of the antimicrobial effect of six natural products in comparison to 2.5% sodium hypochlorite against Enterococcus faecalis: An in vitro study

Abstract

Background: Enterococcus faecalis (E. faecalis) is known to play a key role in the etiology of constant endodontic infections. Recently, suggestions of natural alternatives to overcome the downsides of sodium hypochlorite (NaOCl) have been discussed in the literature. Aims: The present study investigates the antibacterial effect and compares the bacteria-killing time of six possible natural alternatives in comparison to 2.5% NaOCl, namely net Manuka Honey (MaH), crude black seed oil (BSO), 100% apple vinegar (AV), castor oil, crude sesame oil, and a novel plant extract (Bactil®). Materials and Methods: Agar well-diffusion assay was used to determine the antibacterial effect of the products against E. faecalis. Muller‒Hinton broth (MH broth) was used to determine the minimum inhibitory concentration (MIC) and the minimum bactericidal concentrations (MBC). Time-kill assay was performed to investigate the killing time required by the tested product to inhibit E. faecalis at 30, 60, 90, and 120 s. Results: Four out of the six tested products (crude BSO, 0.2% Bactil®, 100% AV, and net MH) exhibited an antibacterial activity against E. faecalis. While after MBC and MIC determination, only two of the products (0.4% BSO and 0.2% Bactil®) were able to inhibit the growth of E. faecalis within 30 s of exposure similar to the positive control 2.5% NaOCl. Conclusion: Within the limitations of this study, both 0.4% BSO and 0.2% Bactil® were as effective as 2.5% NaOCl against E. faecalis and could be suggested for further testing as promising natural alternatives to disinfect the root canal system.

Keywords

• antibacterial
• disinfection
• enterococcus faecalis
• root canal treatment
• sodium hypochlorite