Fluoridated water
“Studies conducted throughout the past 65 years have consistently shown that fluoridation of community water supplies is a safe and effective method in helping to prevent dental decay in both children and adults. Simply by drinking flouridated water, both children and adults can get the benefit of cavity protection whether they are at home, work or school.
Studies prove water fluoridation continues to be effective in reducing tooth decay by as much as 20-40%, even in an era with widespread availability of fluoride from other sources such as fluoride toothpaste.” **http://www.ada.org/fluoride.aspx
Nationwide the number of states that are issuing fluoridated tap water are growing with recent studies showing that at least 73% of the population is being reached. The targeted date to reach the optimal fluoridation goal set by the US Department of Health and Human Services is in the year 2020.
https://www.ada.org/news/7031.aspx