Recent research suggests that the benefits of water fluoridation may have diminished as most toothpastes now contain fluoride.

While community water fluoridation has long been debated, the CDC reaffirmed in May that panels of international experts "have not found convincing scientific evidence linking community water fluoridation with potential adverse health effects."

A federal judge in California recently ordered the U.S. Environmental Protection Agency to strengthen regulations on fluoride in drinking water. However, the judge did not definitively conclude that adding fluoride to water presents unreasonable risks to neurodevelopment.

Since the mid-1940s, fluoride has been added to public water supplies to reduce tooth decay, with toothpaste manufacturers incorporating fluoride into products by the mid-1970s.

According to a systematic review published in the Cochrane Database of Systematic Reviews, researchers analyzed data from 157 studies comparing communities with fluoridated water to those without. The review found that studies conducted prior to 1975 showed a significant reduction in tooth decay among children in communities with fluoridated water.

More recent studies indicate that while fluoridation continues to slightly reduce tooth decay in children, the magnitude of benefit appears to have decreased. The review did not determine whether removing fluoride from water supplies would affect caries rates or whether fluoridation effectively reduces disparities in lower-income nations. Most contemporary studies have been conducted in high-income countries, leaving the impact on low- and middle-income countries less clear.