Inhibitory Activity of Green Tea (Camellia sinensis) Extract on Some Clinically Isolated Cariogenic and Periodontopathic Bacteria

OBJECTIVE: To determine the in vitro inhibitory activity of green tea extract on some clinically isolated cariogenic and periodontopathic bacteria. MATERIALS AND METHODS: Twenty strains of each of Streptococcus mutans, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia were isolated from carious teeth and periodontal pockets of patients with dental caries and periodontal diseases. Green tea extract was prepared by aqueous extraction method and diluted from 50 to 1.56 mg/ml. Standard techniques of agar disk diffusion and broth microdilution assays were applied for qualitative and quantitative determinations of antibacterial activity of green tea extract on each isolates. RESULTS: All clinical isolates of S. mutans (100s%) were sensitive to green tea extract at concentrations 6.25, 12.5, 25, and 50 mg/ml producing inhibition zones ranging from 10 to 38 mm. All periodontopathic isolates (A. actinomycetemcomitans, n = 20, P. intermedia, n = 20, and P. gingivalis, n = 20) (100s%) tested were sensitive to 12.5, 25, and 50 mg/ml of this extract. The minimal inhibitory concentration of green tea extract for S. mutans was 3.28 ± 0.7 mg/ml and for A. actinomycetemcomitans 6.25, for P. gingivalis and P. intermedia 12.5 mg/ml. CONCLUSIONS: Our findings showed that green tea extract exhibited strong antibacterial activity on S. mutans, A. actinomycetemcomitans, P. gingivalis and P. intermedia and therefore may be used in mouthwashes or dentifrices for prevention of dental caries and periodontal diseases.