For over five decades, the American Dental Association has continuously endorsed the fluoridation of community water supplies and the use of fluoride-containing products as safe and effective measures for preventing tooth decay. The majority of bottled waters on the market do not contain optimal levels (0.7-1.2 ppm) of fluoride. And, some types of home water treatment systems can reduce the fluoride levels in water supplies potentially decreasing the decay-preventive effects of optimally fluoridated water. --American Dental Association