A three layer structure model of fluoridated enamel containing CaF2, Ca(OH)2 and FAp

The top surface CaF2 layer acts as a fluoride reservoir and covers a layer of antimicrobial effective Ca(OH)2. Ca(OH)2 is a well-known therapeutic agent. However, up to now Ca(OH)2 has not been described as a reaction product after topical fluoridation. Below the Ca(OH)2 layer an acid resistant apatite species (FAp) was detected which reached directly into the bulk enamel HAp species. The three layer composition identified helps to understand the influence of fluoride application in the pathogenic mechanisms of tooth decay. Each component in this newly suggested structure model has a specific function, which explains how topical fluoridation of enamel reduces dental caries and influences its pathogenic mechanisms.