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Oral Health Home > General Fact Sheets > Fluoride Fluoride

What is fluoride?

Fluoride is one of many of the earth's naturally occurring elements. Fluoride is found in varying amounts in soil, water, plants and most foods and is the 13th most abundant element in the earth's crust. Recommended fluoride usage is one of the most effective ways humans can prevent tooth decay.

How does fluoride prevent tooth decay?

Fluoride works in a number of ways. It units with enamel on the teeth, making them more resistant and interfering with the ability of bacterial plaque to produce acid by-products that promote decay. And, most importantly, fluoride helps repair the early stages of tooth decay.

How is fluoride administered?

Topical fluorides are agents put directly on the teeth such as toothpaste, rinse, gel or fluoride applications received at the dentist's office. Systemic fluoride is ingested and swallowed and is obtained from fluoridated water, vitamins and fluoride tablets and drops and is beneficial to developing teeth.

Research indicates combinations of systemic and topical fluoride such as drinking fluoridated water and using fluoridated toothpaste and other fluoride products helps make teeth resistant to decay.

What is water fluoridation?

All water contains some fluoride. Fluoridation is the process of adjusting the natural level of fluoride in the water supply to the optimal concentration necessary for protection against tooth decay. Concentrations vary and are dependent on the temperature and climate of the environment from which the water derives. Typical concentrations range from 0.6 to 1.2 parts per million (ppm), equivalent to 0.6 to 1.2 milligrams per liter (mg/l) or about a drop per 13 gallons.

Should you fluoridate?

Health professionals are aware of the benefits of water fluoridation. Fluoridating community drinking water is safe, economical and by far the single most effective way of preventing tooth decay, one of the nation's most widespread diseases and the number one reason for tooth loss among all ages. People who drink optimally-fluoridated water from birth will experience approximately 20-40 percent less tooth decay in their lifetime.

Is water fluoridation the only way to prevent tooth decay?

In communities where the water supply is not fluoridated or where there is no central water supply, dentists and physicians may prescribe fluoride tablets or drops for children to take daily. Fluoride may also be added to the school water supply. In schools where there is no fluoridation, children may benefit from home fluoride mouthrinse or fluoride applications at the dentist's office.

Is there evidence that fluoridation is harmful?

No. The media has reported data from an incomplete study by the National Toxicology Program (NTP). The study reported of more than 1,000 mice and rats tested, five young male rats showed evidence of a rare bone cancer after consuming water with 45 ppm and 79 ppm fluoride. At the time of the media report, data had not been subjected to final analysis. For an average person (weighing approximately 150-pounds) to consume 45 ppm fluoride and 79 ppm fluoride in drinking water, they would have to drink 380 and 667 8-ounce glasses of water daily, respectively. It is important to note that no male or female mice or female rats developed cancerous lesions in the study, leaving researchers to theorize an aberrant strain of male rats might have been used. Nonetheless, James O. Mason, MD, assistant secretary for Health and head of the Public Health Service, requested a comprehensive review of the study. A year-long investigation was conducted by the US Public Health Service which reported no evidence establishing an association between fluoride and cancer in humans. Forty years of research involving hundreds of studies has confirmed that fluoridation is safe and effective when used in the recommended manner.

Who supports fluoridation?

Fluoridation of community water supplies is a valuable public health measure supported by the American Dental Association, the American Medical Association, the American Cancer Association, the American Heart Association, the American Public Health Association, the National Academy of Sciences and virtually every other major American organization in the fields of health, science and public affairs.