Fluoride works by strengthening the outer enamel layer of teeth to reduce the occurrence of cavities and to lessen tooth sensitivity. Where fluoride has been added to municipal water supplies, there has been a marked decline in tooth decay rates. However, individuals with increased sensitivity, areas of thin, weakened or developing enamel, or who simply are not exposed to fluoridated water may benefit from supplemental fluoride treatments in conjunction with a dental cleaning. Professionally applied topical rinses, gels, foams and varnishes are available. If you prefer to avoid fluoride, xylitol rinses are available for home use and are a natural, safe and effective alternative.