Controlled-release delivery systems have been investigated for use in fluoride therapy as a result of their ability to control the rate and site of fluoride release. Both sustained-release fluoride delivery systems and controlled-release fluoride preparations have been developed, including sustained-release fluoride tablets, fluoride-releasing polymers, microencapsulated fluoride in aerosols, and membrane-controlled fluoride reservoirs. Laboratory and clinical studies have confirmed the ability of these preparations to produce high levels of fluoride in saliva and plaque without toxic or adverse side effects. From these studies, it appears that controlled-release fluoride delivery systems have great potential as effective anticaries agents in cariesprone populations.