Methods: In this ex vivo study, 44 extracted human single rooted teeth were prepared with rotary nickel-titanium instruments and irrigated with EDTA 17% and sodium hypochlorite 5.25% to remove smear layer. All canals were inoculated with an Enterococcus Faecalis suspension for 2 weeks, then the samples were divided into two experimental groups (20 canals in each group) and two positive and negative controls. The infected canals in group 1 and 2 were dressed by GTE and calcium hydroxide creamy pastes, respectively. All restored samples were kept in incubator at 37°C humid environment for a week. Then, dentinal shavings were harvested from each root canal wall the following day and transferred to Bile Esculin Agar plate to culture and count colony forming units of E.Faecalis. The CFU/ml data were statistically analyzed by Mann U-Whitney test.
Results: Significant statistical difference was observed between each experimental group and control group (P<0.05). The percentage of bacterial reduction in group 1 and 2 was 92.47% and 99.86 %, respectively (P<0.05).
Conclusions: It seems that intracanal dressing of both calcium hydroxide and Green Tea Extract (GTE) may exert an effective antimicrobial action against E.Faecalis inside the dentinal tubules. Regarding other benefits of herbal green tea, it might be used as a suitable alternative for disinfecting canal medication.