The effect of Camellia Sinensis (green tea) mouthwash on plaque-induced gingivitis: a single-blinded randomized controlled clinical trial

Abstract
Abstract Background and the purpose of the Study Complementary medicine received high attention during last decades. We aimed to assess the efficacy of Green tea mouthwash on plaque-induced gingivitis as the most common form of periodontal disease. Methods and materials We designed a single blinded placebo controlled clinical trial. High school female students with chronic generalized plaque-induced gingivitis were distributed to receive either 5 ml of Green tea 5% two times/day or normal saline with the same dosage. Gingival index (Sillness & Loe), plaque index (Sillness & Loe) and bleeding index (Barnett) were recorded at baseline and five consecutive weeks. Comparisons were made by a general linear model, repeated measure ANOVA and a Bonferroni test applied for multiple comparisons. Results Twenty five students were recruited in each arm of the study. A significant improvement was observed in all periodontal indices during the study (P < 0.001). Two groups were contrasted by changing patterns of alteration of indices (P < 0.05). Although total amount of improvement was higher in mouthwash group, the differences did not reach a statistically significant level (P > 0.05, observed power for GI: 0.09, PI: 0.11 and BI: 0.07). Conclusion Green tea mouthwash may be a safe and feasible adjunct treatment for inflammatory periodontal diseases. A future larger scale study is warranted for better evaluating the effect of green tea.