By the 1950s, the U.S. government's Public Health Service and the American Dental Association acknowledged the success of water fluoridation in reducing cavities. That led to the broad U.S. adoption of adding fluoride in community water supplies and eventually its inclusion in dental products such as toothpaste and mouthwash.

Fluoride helps protect teeth by making the hard outer layer—the enamel—more resistant to acid attacks by bacteria and sugars. When acid starts to wear down enamel, fluoride draws in calcium and phosphate to rebuild the weakened areas, in a process called remineralization.

Florida has become the second state in the nation to ban the addition of fluoride to public drinking water. On Thursday, Gov. Ron DeSantis signed the Florida Farm Bill, which includes language banning the use of any additive in a public water system that does not meet the new definition of a “water quality additive”: a chemical or substance used in public water to specifically address drinking water standards,