RESUMO
Objective@# The purpose of this study was to compare the effects of different concentrations of green tea on salivary flow rate and pH value. @* Methods@# 20 healthy college students aged from 18 to 25 were included in this study, at State Key Laboratory of Oral Diseases, West China College of Stomatology, Sichuan University. Salivary flow rate and pH value were measured between 21: 00 and 22: 00 after drinking water, low, medium, and high concentration of green tea. @*Results@#Female salivary flow rates in low and medium concentration group were significant higher than that in high concentration group and water group (F=5.20, P < 0.01). There was no significant difference in male salivary flow rates among 4 groups (F=1.810, P=0.143). Salivary pH value in 3 green tea groups were lower than that in water group (F=3.50, P=0.02), with no significant difference among them. @*Conclusion@#Low and medium concentration green tea prevent decrease of salivary flow rate in healthy women but not in males. Salivary pH lowers after drinking different concentrations of green tea.