Fluoride content of commercially-available bottled water in Bangkok, Thailand

Aim: To determine the fluoride content of commercially-available bottled water in Bangkok. Methods: Thirty brands of bottled water (17 bottled plain water and 13 bottled mineral water) were obtained from supermarkets in Bangkok. Two randomly-selected samples of each brand were purchased 6 months apart. A 5-mL sample was mixed with 5 mL of total ionic-strength adjusting buffer III. The fluoride content of each sample was determined in triplicate by a fluoride ion-selective electrode. Fluoride standards ranging in concentration from 0.01 to 1.00 ppm were used to calibrate the measurements. Data were analyzed by Statistical Package for the Social Sciences software, version 13.0. Results: The fluoride content of bottled water in Bangkok ranged from 0.03 to 0.72 ppm, with a mean +/- standard deviation of 0.17 +/- 0.16 ppm. The mean fluoride content of bottled mineral water was slightly higher than that of bottled plain water, but the difference was not statistically significant. Conclusions: Most commercially-available bottled water in Bangkok contains negligible amounts of fluoride. This serves as baseline data for dentists prescribing a fluoride supplement to make the utmost use of the fluoride caries preventive effect, while avoiding adverse effects, such as dental fluorosis.