Relationship between fluorescence loss of QLF and depth of demineralization in an enamel erosion model

The purpose of this study was to assess the relationship between quantitative light-induced fluorescence (QLF) values and demineralization depths in an enamel erosion model in vitro. Flat labial enamel surfaces of bovine incisors were ground with 800-grit SiC and coated with nail varnish, but also leaving rectangular windows of enamel uncoated. Subsequently, they were immersed in a lactic acid gel (pH 5.0) for 0 to 7 weeks to make an enamel erosion model. Carious lesions thus induced were analyzed by QLF and the demineralization depths measured using SEM/EDS method at the end of each period. A wide range of erosive lesions were produced with a steady increase in both demineralizing depth and fluorescence loss (Delta F) over time. With this model, a good correlation was exhibited between each Delta F value and the demineralization depth. Results of this study indicated that QLF could detect and quantify mineral loss under the eroded surface of the enamel erosion model