Drinking water containing 1 mg of fluoride per liter is considered to be roughly the optimal amount for the prevention of tooth decay. For those without access to fluoridated drinking water, chewable fluoride tablets containing 0.25 to 1 mg per day of fluoride or fluoride mouthrinses with 0.05% to 0.2% fluoride content can be used. Liquid fluoride drops are also available.

Fluoride is a trace mineral found in varying concentrations in foods and in water. Foods high in fluoride include fish, tea, and many different vegetables. Fluoride is added into the municipal water supply of many cities in the United States. For those people without access to fluoridated water, fluoride supplements are available in the forms of tablets and drops. These supplements are not available without a prescription. Many non-prescription dental care products contain fluoride as well, including toothpastes and mouthwashes.

As fluoride is not considered an essential mineral, it does not have an associated deficiency state. Regardless, people living in areas with low concentrations of fluoride in the drinking water do appear to be at a higher risk of significant tooth decay than those living in areas with high amounts of natural or added fluoride.

The risks associated with fluoridation of the public water supply have been the subject of vigorous and often heated debate since fluoridation began in 1945. Although much research has been done regarding the safety of fluoridation, a recent review found all prior studies to be of sub-optimal quality and far from definitive.¹

Some,^{2 , 3} but not all,^{4 , 5} studies have found a correlation between the amount of fluoride intake and increased risk of osteoporotic fractures. The validity of the studies that found increased risk of fracture in communities with fluoridated water has been questioned by some scientists.⁶ A pooled analysis of 29 studies on this issue concluded that there did not appear to be an increased risk of fracture in areas of water fluoridation.⁷

Dental fluorosis, a brown staining of teeth due to fluoride exposure during childhood, is the best-documented adverse effect of fluoride. At a water fluoride level of 1 part per million (or 1 mg per liter), roughly 13% will have fluorosis to an aesthetically concerning degree.⁸

Some scientists have concluded that water fluoridation is associated with an increased risk of bone tumors,⁹ although most others disagree.¹⁰