Effect of Green Tea on Salivary Flow Rate and pH

Objectives: Previous researches suggested that green tea (Camellia sinensis) may prevent tooth decay and periodontal disease. Since salivary flow rate and pH were the influencing factors on caries incidence, this study was purposed to determine the effect of green tea beverage on these factors. Methods: unstimulated saliva were collected for 10 min. from 30 healthy, 20-22 year old subjects before and after drinking 250 ml of 25% green tea beverage by straw. The amount of saliva was measured for flow rate calculation and the pH of saliva collected at before, and 1, 5 and 10 min after drinking were determined by pH electrode. The differences of the mean flow rate and pH before and after drinking were analyzed using paired t-test. Results: it was found that the mean flow rate after drink (0.49±0.182ml/min) was significantly higher than the mean flow rate before drinking (0.41±0.126 ml/min) (p<0.05) and the mean pH at 1, 5 and 10 min after drink (7.74±0.318, 7.42±0.299 and 7.23±0.362, respectively) were significantly higher than the mean pH before drink (7.14±0.272) (p<0.05). Conclusions: these findings suggested that green tea was capable to increase salivary flow rate and pH which probably help to decrease caries incidence when it was taken after food intake. This study was supported by the Dental Research Fund, Faculty of Dentistry, Grant 11113/2004.