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
Water fluoridation was first adopted in Brazil in the city of Baixo Guandu, ES, in 1953. A 1974 federal law required new or enlarged water treatment plants to have fluoridation, and its availability was greatly expanded in the 1980s, with optimum fluoridation levels set at 0.8 mg/L. Today, the expansion of fluoridation in Brazil is a governmental priority; Between 2005 and 2008, fluoridation became available to 7.6 million people in 503 municipalities. As of 2008, 3,351 municipalities (60.6%) had adopted fluoridation, up from 2,466 in 2000.