Comparison of fluoride concentration in several types of green tea consumed in Iran

  Background: Tea is known as a source of fluoride that not only can prevent tooth decay but also can increase the risk of dental fluorosis in overuse or in combination with other sources of fluoride.   Objective: The aim of this study was to compare the fluoride concentration in three brands of green tea consumed in Iran .   Methods: This experimental study was conducted in Qazvin University of medical Science during 2012. Three brands of green tea (bag type and packed type) were evaluated. Two bags of every bag type and two 1-gram samples of every packed type were selected. Each time, the samples were placed in 100 ml distilled boiling water and were restored in an incubator at 80 ºC. Three and ten minutes after tea brewing, the fluoride concentration of filtrated water was measured by chromatography and was recorded in milligram per liter. Data were analyzed using ANOVA and repeated measures ANOVA .   Findings: The fluoride concentration in bag type green tea was more than packed type. The fluoride concentration was not different among three brands of green tea. The fluoride concentration after ten minutes brewing was not significantly different from the concentration after three minutes brewing.   Conclusion: With regards to the results, it seems that green tea brand and the brewing time does not affect fluoride release. The fluoride release in bag type green tea is more than packed type.