The addition of fluoride to public water supplies to prevent tooth decay at a community level.

Water fluoridation is recognized by major health organizations as one of the most effective public health measures for preventing tooth decay. At optimal levels (0.7 ppm), fluoride in water reduces cavities by 25% in children and adults. Fluoride works by promoting remineralization of early decay, making enamel more resistant to acid attacks, and inhibiting bacterial acid production. Not all communities have fluoridated water, so alternative fluoride sources may be recommended.