The use of controlled and sustained release agents in dentistry: a review of applications for the control of dental caries.

Three types of sustained and controlled release dosage forms of sodium fluoride (NaF) for the prevention of dental caries are reviewed. Sustained release NaF tablets or capsules have prolonged the elevation of saliva and plasma fluoride levels in both animal and human studies when compared to conventional NaF tablets. In vitro studies have shown that aerosol application of NaF-containing microcapsules to the tooth surface may prolong the retention of a given dose of fluoride in the mouth and also increase enamel uptake of fluoride. A membrane-controlled reservoir-type intra-oral controlled release device for NaF is potentially the most effective dosage form of NaF developed to date. Devices releasing 0.02 to 1.0 mg of fluoride per day for 30 to 180 days have been prepared. Extensive testing has shown that the devices function under both in vitro and in vivo conditions and the device has been approved by the US Food and Drug administration for preliminary testing in humans.