Thesis (M.Sc.) - Cairo University - Faculty of Oral and Dental Medicine- Department of Endodontics

The purpose of this study was to compare the antibacterial efficacy of Green Tea extract (GT, camellia sinensis) and 5.25 % Sodium hypochlorite (NaOCl) as root canal irrigants, evaluate the effect of GT on dentin hardness compared to NaOCl, and also study the cytotoxic effect of GT on fibroblast compared to NaOCl. Dried and ground Green tea leaves were extracted with 70% ethyl alcohol/water with the ratio 1:5.The mixture was stored in the darkness for two weeks, and then filtered through filter paper. The filtrate was kept in the fridge and the residue was re-macerated in the same solvent for another week and filtrated the same way. The resulting filtrate was combined with the first filtrate. The combined filtrate was evaporated using Rotavapour® at 50{u00B0} untill dryness. The resulted crude extract was weighed to calculate the percentage, and different concentrations were prepared; i.e 3%, 6%, 12%. In this study, 80 human single rooted teeth were inoculated with E.Faecalis and incubated for one week. Teeth were then prepared by using protaper rotary files, both shapers and finishers and irrigated with the tested irrigants; group 1: saline, group 2: 5.25% NaOCl, group 3: 3%GT, group 4: 6%GT, group 5:12% GT. Samples were collected and smeared on agar plates, then plates were incubated for 24 hours. E.facalis colonies were counted by visualization of white pin point colonies, then the number of CFU/samples was calculated

Issued also as CD