(HealthDay News) -- Fluoride is a well- known fighter of tooth decay, which occurs when acid-producing bacteria dissolve the hard enamel that protects teeth.

Fluoride helps strengthen the enamel, the Nemours Foundation says, and the chemical can also help teeth repair damage that has already been done.

Although fluoride is found or added in most public water supplies, some areas don't have fluoridated water. If you live in such an area, your dentist may suggest a fluoride supplement in the form of a drop, tablet or vitamin.