Fluoride Levels in Saliva after Tea Intake

Tea contains fluoride but its effect as a caries-preventive measure is not fully understood. The aim of this study was to evaluate the fluoride levels in saliva after tea-intake. Part one of the study analyzed the fluoride content of teas and one black and one green tea was thereafter selected for the clinical part of the study (part two). Ten healthy adults participated in part two which was designed as a prospective, crossover study where the salivary fluoride levels were analyzed after tea-intake at designated follow-ups. The fluoride level in saliva increased after tea-intake (0.04 ± 0.2 vs 0.97 ± 0.32 mg/L, (p < 0.01)). After intake of the black tea fluoride levels remained elevated compared to baseline at 5 minutes (0.04 ± 0.02 vs 0.12 ± 0.08 mg/L, ( p < 0.01)) and 10 minutes (0.04 ± 0.02 vs 0.09 ± 0.07 mg/L, (p < 0.05) but not at 20 minutes (0.04 ± 0.02 vs 0.05 ± 0.03 mg/L, (p = 0.056)). The green tea had elevated fluoride levels up to 5 minutes (0.05 ± 0.03 vs 0.14 ± 0.09 mg/L, (p < 0.01)) but not at 10 minutes (0.05 ± 0.03 vs 0.09 ± 0.08 mg/L, (p > 0.05)). The fluoride level in saliva is elevated after tea-intake which may suggest a caries-preventive effect, but not for a long period of time due to its rapid clearance in saliva