Ex Vivo Comparative Study of the Effect of Different Concentrations of Green Tea Extract and Two Common Irrigants on Root Canals Infected with Enterococcus faecalis

Background and Aim: One of the main goals of endodontic treatments is to disinfect the root canal and dentin tubules. This study compared the antimicrobial effect of different concentrations of green tea extract with that of two common irrigants on Enterococcus faecalis (E. faecalis) in the root canal system. Materials and Methods: In this experimental study on 124 single canal teeth, suspensions derived from the 24-hour culture of E. faecalis were inoculated into the canals, and the samples were incubated for two weeks. Then, the teeth were divided into six experimental groups (n=20) and two control groups (n=2). In the first group, 5% sodium hypochlorite (NaOCl), in the second group, 2% chlorhexidine gluconate (CHX), in the third group, 3.125% green tea extract, in the fourth group, 12.5% green tea extract, in the fifth group, 25% green tea extract, and in the sixth group, normal saline was used for root canal irrigation. The next day, the extracted liquid from vortexed dentin fragments was cultured, and the colony-forming units (CFU) were counted 48 hours later. Data were analyzed using Mann-U-Whitney test. Results: The CFU count for NaOCl and CHX showed a statistically significant difference compared to different groups of green tea extract (P