The Dental Fluoridation Potential of Drinking Water.

Water fluoridation is commonly cited as one of the greatest health achievements of the 20th century because of its effectiveness in reducing the incidence of dental caries. Despite the breadth of research on the subject, little is known about how variation in the composition of municipal water may affect the uptake of fluoride by tooth enamel. This study addressed this issue by developing a model system for testing fluoride uptake into hydroxyapatite, the primary mineral of tooth enamel, to investigate how varying water composition influences fluoride uptake. The tested water variables included the pH and degree of water hardness. A representative experiment involving several municipal water sources then examined how this approach can be used to measure fluoride uptake from any sample of drinking water. Aside from an optimal pH of 6 to 7 for fluoride uptake, there was a remarkable constancy to the uptake of fluoride by hydroxyapatite from the many water samples evaluated. These findings, therefore, suggest that for a given individual's personal history, any observed variation in enamel fluoridation is less likely to be the result of variation in the composition and geographical source of the fluoridated water and more likely a consequence of individual behavioral and biological factors that conceivably affect fluoride uptake into tooth enamel.