Fluoride is effective at preventing dental caries through several mechanisms: it reduces demineralization by lowering bacterial acid production and enamel solubility; increases remineralization of incipient lesions; and interferes with plaque microorganisms. Topical fluoride treatments delivered professionally as gels, foams, varnishes or professionally-applied solutions provide a localized source of fluoride to tooth surfaces, while systemic fluoride from water or supplements provides lower levels of fluoride incorporated into developing teeth and bone.