Fluoride retention in dental biofilm: role of bacterial calcium binding and in situ anticariogenic potential

Abstract

Despite the decline in dental caries in the last decades, the disease remains severe in groups of individuals, for whom effective prevention measures should be researched. Thus, the study of fluoride (F) retention in dental biofilm and its role as an ion source to the biofilm fluid, where ion exchange between the tooth and biofilm occurs, could help to develop methods that increase F retention. F is retained in dental biofilm: 1 due to bridging to calcium ions (Ca) on bacterial surfaces or 2 as the mineral calcium fluoride. From these reservoirs, both Ca and F could be released to plaque fluid during a pH drop, to interfere with de/remineralization events, but this has not been explored. In a study in progress, supported by FAPESP, a series of experiments is being conducted to evaluate the kinetics of Ca and F binding to bacterial surface and their release as a function of time and pH. However, the clinical significance needs to be tested in conditions similar to the oral environment. As an expansion of the current studies, the role of Ca and F retained on bacterial surfaces or as calcium fluoride will be studied with an in situ caries model, to evaluate the potential of each of these reservoirs as a source of ions to biofilm fluid, to interfere with the dynamics of the caries process. (AU)