Evaluation of developmental defects of enamel and differential diagnosis from dental caries using quantitative light-induced fluorescence technology: A cross-sectional investigation

Abstract

Objectives: Dental caries and developmental defects of enamel (DDE) are common conditions that impact oral health. Quantitative light-induced fluorescence (QLF) is widely used for detecting dental caries, but its ability to identify DDE remains unclear. This study aimed to investigate fluorescence differences among sound, carious, and DDE-affected teeth using QLF, and to differentiate white hypomineralization from incipient caries. Methods: Data from 704 teeth in 137 patients under 20 years old were analyzed. QLF images were acquired, and fluorescence parameters were measured. Statistical tests included Chi-square, Fisher's exact, Mann-Whitney, Kruskal-Wallis, Linear mixed-effects models, and receiver operating characteristic (ROC) analyses. Results: Delta F values progressively decreased and Delta R values increased from sound to DDE-affected to carious teeth (p < 0.001). Within DDE, fluorescence changes differed significantly according to defect subtype, with combined defects showing the greatest mineral loss and bacterial activity (p < 0.001 for Delta F, p = 0.008 for Delta R). White hypomineralization showed higher Delta F values and lower Delta R values than yellow/brown hypomineralization (p < 0.001). Significant fluorescence differences were observed between white hypomineralization and International Caries Detection and Assessment System scores 1 and 2 lesions (p < 0.001). ROC analysis revealed excellent accuracy for distinguishing white hypomineralization from incipient caries, with areas under the curve of 0.970 for Delta F mean and 0.979 for Delta R mean. The optimal cutoff values were -7.65 for Delta F mean and 23.50 for Delta R mean, respectively. Conclusions: QLF provides effective quantitative support for differentiating DDE from incipient caries. Clinical Significance: Quantitative light-induced fluorescence provides objective parameters for differentiating developmental defects of enamel from incipient dental caries. By offering quantitative cutoff values, this approach supports more accurate diagnosis of clinically ambiguous white spot lesions, reduces the risk of overtreatment, and facilitates prevention-oriented and minimally invasive treatment planning in routine dental practice.