Water fluoridation
Health and dental organizations worldwide have endorsed its safety and effectiveness. Its use began in 1945, following studies of children in a region where higher levels of fluoride occur naturally in the water. Further research showed that moderate fluoridation prevents tooth decay.
Water fluoridation
In the first half of the 19th century, investigators established that fluoride occurs with varying concentrations in teeth, bone, and drinking water. In the second half they speculated that fluoride would protect against tooth decay, proposed supplementing the diet with fluoride, and observed mottled enamel (now called severe dental fluorosis) without knowing the cause. In 1874, the German public health officer Carl Wilhelm Eugen Erhardt recommended potassium fluoride supplements to preserve teeth. In 1892 the British physician James Crichton-Browne noted in an address that fluoride's absence from diets had resulted in teeth that were "peculiarly liable to decay", and who proposed "the reintroduction into our diet ... of fluorine in some suitable natural form ... to fortify the teeth of the next generation".