Fluoride, a mineral, is naturally present in many foods. Fluoride is the ionic form of the element fluorine, and it inhibits or reverses the initiation and progression of dental caries (tooth decay) and stimulates new bone formation
Fluoride and health
Dental caries occurs when cariogenic bacteria in the mouth ferment foods and produce acids that dissolve tooth mineral. Over time, this tooth decay can cause pain and tooth loss. Without treatment, dental caries can cause infections, impair growth and weight gain during childhood, affect school performance, impair quality of life, and possibly result in death. Adequate fluoride intakes reduce the risk of dental caries in its initial stages by inhibiting demineralization and the activity of bacteria in dental plaque and by enhancing tooth remineralization.
Source: Fact sheet from the National Institute of Health