Fluoride tablets may help young children, but they've not been proven to help adults

Readers: Fluoride can make your teeth stronger and reduce the risk of developing cavities. The preventive potential of fluoride is one of the major advances in dentistry in the last century.

But how much is enough? If you haven't had cavities in the last few years, the combination of brushing with fluoride toothpaste twice daily and drinking optimally fluoridated water should give you sufficient exposure, according to a recent issue of Mayo Clinic Health Letter. Too much fluoride can cause spots on your teeth.

But if you're at higher risk -- having had cavities recently, a water supply with low fluoride or a problem such as dry mouth that can lead to tooth decay -- your dentist also may recommend using fluoride treatments at home or a professional application of fluoride gel two to four times a year. Fluoride tablets may help young children, but they've not been proven to help adults after enamel has formed.