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 controversy
In areas with complex water sources, water fluoridation is more difficult and more costly. Alternative fluoridation methods have been proposed, and implemented in some parts of the world. The World Health Organization (WHO) is currently assessing the effects of fluoridated toothpaste, milk fluoridation and salt fluoridation in Africa, Asia, and Europe. The WHO supports fluoridation of water in some areas. In some other countries, sodium fluoride is added to table salt.