The American Dental Association (ADA) recommends a professional fluoride treatment at the dentist’s office every 3, 6, or 12 months, depending on your oral health. Fluoride works by restoring minerals to tooth surfaces where bacteria may have eroded the enamel. It can also inhibit the growth of harmful oral bacteria and further prevent cavities. The earlier children are exposed to fluoride, the less likely they are to develop cavities. A large study found that children and adolescents who received fluoride treatments for one year were 43 percent less likely to have tooth decay and cavities.