Long-term study shows fluoridation benefits adults.
An Australian study has found that consuming fluoridated water significantly reduces tooth decay, even if its use doesn't start until adulthood. The study examined data from 3,779 older teens and adults who had lived for various amounts of time in fluoridated communities. Survey examiners measured levels of decay, and study participants reported where they had lived since 1964. The researchers then determined the percentage of each participant's lifetime in which the public water supply was fluoridated. They found that adults who had lived more than 75% of their life in fluoridated communities had about 30% less tooth decay than those living 25% or less in fluoridated areas. People with the longest exposure to fluoride had the greatest benefit, but even those who were born before fluoridation was widely adopted received some benefit. [Slade GD and others. Effects of fluoridated drinking water on dental caries in Australian adults. Journal of Dental Research 92:376-382, 2013] https://www.ncbi.nlm.nih.gov/pubmed/23456704