The use of fluoride has been endorsed as a safe and effective method of preventing tooth decay by most major health and safety-related organizations. When fluoride enters the mouth it is deposited into the teeth and bones, strengthening teeth during a process called remineralization.

Fluoride is a mineral that appears naturally in soil, water, air and certain foods. It is often added to community drinking water when levels are deemed insufficient to help protect against tooth decay. Sometimes fluoride supplements (in the form of tablets, drops or lozenges) are used to compensate for drinking water without adequate fluoridation.

Fluoride is also directly applied to the teeth as part of routine oral care. Brushing teeth with fluoride toothpaste is an important component of good daily dental hygiene. Fluoride may also be topically applied as fluoride gels, mouth rinses, and during professionally applied fluoride treatments. Anyone at high risk of tooth decay may benefit from fluoride treatments that use higher concentration levels of fluoride than those available in over-the-counter products.

All age groups can benefit from fluoride. In children, fluoride fortifies and strengthens teeth while they are still forming. Children who receive adequate levels of fluoride during this time develop permanent teeth that are more resistant to decay the moment they appear in the mouth. Adults with root exposure or dry mouth are particularly susceptible to tooth decay, and can benefit from tooth-strengthening applications of fluoride.

Risks are associated with exposure to high levels of fluoride over prolonged periods of time. Dental fluorosis affects teeth that are still forming and have not yet erupted into the mouth, and most often occurs in children who take fluoride supplements in addition to consuming adequate levels of fluoridated water.

Large concentrations of fluoride consumed at one time may be toxic or even fatal, especially to small children. Bone weakening and skeletal fluorosis (which cause joint stiffness and pain) have been associated with exposure to high levels of fluoride for long periods of time, although further study is needed in these areas.

Parents or caregivers can help prevent fluoride overdose by supervising the use of fluoride products in children during dental hygiene. Parents should also keep all fluoride products (including toothpaste and mouth rinses) out of reach of children and avoid stockpiling fluoride supplements to help prevent cases of accidental overdose.

Maintaining adequate fluoride levels is important to prevent tooth decay and reduce the risks of overexposure, such as dental fluorosis. This includes identifying and monitoring fluoride levels in drinking water sources, whether community, well or bottled water. In some cases of naturally high levels of fluoridated water, it may involve filtering fluoride from drinking water with certain types of home filtering systems.