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.
Fluoridation by country
The first community water fluoridation programme was in Kyoto prefecture in 1952, lasting 13 years. The second was established by US military authorities in Okinawa prefecture in 1957, lasting 15 years. The last experience was in Mie Prefecture in 1967, lasting 4 years.