Fluoridation

Fluoridation is the controlled adjustment of the concentration of fluoride in drinking water or other substances to prevent dental caries. It most commonly involves adding fluoride to public water supplies, but salt fluoridation and milk fluoridation are used in some regions. The aim is to deliver low-level fluoride to a large population.

The practice began with early 20th-century observations linking fluoride to lower tooth decay. In 1945 Grand Rapids, Michigan, became the first city to fluoridate its drinking water. Following successful studies, many communities worldwide adopted the practice, though it remains controversial in some countries.

Fluoride strengthens enamel and inhibits bacterial acid production, reducing caries risk. The recommended long-term level in the United States is about 0.7 mg/L of water; other regions adjust for climate, water consumption, and ambient fluoride levels.

Public health agencies cite net reductions in dental decay with optimized fluoridation. Potential adverse effects include dental fluorosis during tooth development if exposure is excessive; skeletal fluorosis is rare under controlled conditions. Ongoing monitoring helps maintain safety.

Programs are typically overseen by public health departments and water utilities, with quality control to maintain target concentrations and protect infrastructure. Public communication and consent considerations are part of program governance.

Globally, some countries do not fluoridate water. Alternatives include salt fluoridation and milk fluoridation, used where water fluoridation is impractical. In areas with high fluoride from natural sources or widespread fluoride toothpaste use, impact varies.

Evidence from systematic reviews indicates substantial reductions in caries, though debates persist about medicalizing a public resource, potential risks, and individual choice. Proponents emphasize cost-effectiveness and population-wide benefits.