Antibacterial efficacy: Sodium hypochlorite, chlorhexidine and herbal irrigants against Enterococcus faecalis

Abstract

Persistent Enterococcus faecalis biofilm contributes to post-treatment endodontic disease and remains a useful model for comparing root-canal irrigants. This in vitro study inoculated 150 extracted single-rooted human premolars with E. faecalis for 21 days and randomized them to 3% sodium hypochlorite, 2% chlorhexidine, 10% Triphala, 10% neem, or saline (n=30 per group). Post-irrigation bacterial reduction was assessed by colony counts, confocal viable-cell percentage and residual dentinal-tubule penetration. Mean post-irrigation log10 CFU/mL was 1.18 ± 0.42, 1.74 ± 0.51, 2.33 ± 0.58, 2.56 ± 0.61 and 5.71 ± 0.45, respectively, with corresponding viable-cell percentages of 6.8 ± 3.1%, 11.9 ± 4.7%, 18.6 ± 6.2%, 22.4 ± 7.0% and 72.5 ± 8.4% (p<0.001). Thus, sodium hypochlorite produced high antibacterial effect, followed by chlorhexidine, while Triphala and neem significantly reduced E. faecalis compared with saline but remained less effective than conventional irrigants.