Fluoride, a mineral, plays an important part in preventing tooth decay. It works by making the tooth more resistant to plaque buildup. Part of this mineral is lost every day when the tooth enamel is attacked by things such as sugars in the mouth.
In other words, fluoride can help repair your teeth. The fluoride treatment you receive in a dental office is much more concentrated than what you would find in over-the-counter toothpastes or fluoride mouthwash.
If this is a concern, ask your dentist if a professional fluoride treatment might be right for you.