The proposed study is intended to explore and evaluate the potential of phosphonylated polymers (PPN) as anticaries agents. Preliminary results have revealed that a water and alcohol soluble PPN can be deposited on apatite from solution. These polymers were found to have substantial affinity for tooth-enamel surfaces, thus forming a strongly bound protective layer. It was also found that fluoride-releasing groups can be incorporated into the PPN polymer, and that fluoride release from such an adsorbed polymer can be expected to occur over an extended period in the immediate vicinity of the tooth surface. These results indicate that it should be possible to develop a mouthrinse-applied anticaries treatment for use in community and personal-care programs that would provide extended protection. Three series of polymers will be prepared, each based on a different polymer backbone. Each series will contain varying numbers of phosphonate and fluoride-releasing groups so that each will exhibit varying degrees of enamel affinity and fluoride-releasing capacity. Much of the chemistry required to prepare these unique polymers has been developed by the present investigators. The affinity of these polymers for apatite surfaces, and their fluoride-releasing capacity, will be used to select promising examples for further study. The selected polymers will be studied to determine their effect on the solubility of hydroxyapatite and enamel (both in acid buffers and when colonized with S. Mutans), on transport of ions into and out of apatite structures, and on changes in mineral content. The results of this investigation are expected to provide basic information as to the means whereby fluoride-releasing, phosphonylated polymers can be used for long-term protection against dental caries.