In the 30 years since Dean's classical studies demonstrated the importance of fluoride in prophylaxis of dental caries,1,2 well-controlled studies have repeatedly corroborated the efficacy and safety of communal water fluoridation programs. Evidence indicates that in regions in which the communal water supply naturally contains or has added to it fluoride ion in concentrations of 1 ppm (part per million), the incidence of dental caries in children is approximately half that found when the drinking water contains less than 0.2 ppm, and the benefits extend into adult life.
The most effective and least expensive method of caries prophylaxis for the general population is adjustment of the fluoride concentration of the community water supplies to 1 ppm. Significant progress has been made in making the benefits of communal water fluoridation available to large segments of the population (over 43,000,000 in the United States and over 3,800,000 in Canada). However, many