Quantitative light fluorescence (QLF) assessment of mild and moderate enamel fluorosis in primary teeth

Abstract

Enamel fluorosis affects both permanent and primary teeth; however, there are few studies on primary teeth. Fluorosis in primary teeth is difficult to diagnose for mild and moderate cases. Quantitative light-induced fluorescence (QLF) has been used for enamel fluorosis on the permanent dentition, but there are no current studies on primary fluorotic teeth. The purpose of this study was to assess mild to moderate enamel fluorosis in primary teeth using QLF. The buccal surfaces of exfolicated and extracted primary teeth (n=113) were visually examined and classified using the Thylstrup & Fejerskov Index (TFI) for fluorosis into categories TFI-0 to TFI-4. Fluorescence images were acquired. Image analysis was performed using the complete tooth surface (S) and through the selection of a Region of Interest (ROI), which was determined as the region where the fluorosis lesions were more representative and with at least a minimum of adjacent sound area. Area (mm2), fluorescence loss (%) and ΔQ (mm2×%) values were obtained. The correlation between QLF variables and visual diagnosis was determined using the Kendall-tau coefficient. Sencitivity, specificity, and Receiver Operating Characteristic analysis was performed for QLF versus visual diagnosis. Moderate to strong positive correlation was found between QLF and visual diagnosis using the ROI. QLF showed greater sensitivity and specificity for the diagnosis of mild fluorosis than moderate fluorosis and with the ROI analysis than with S. QLF was a useful tool for the assessment of mild and moderate fluorosis in primary teeth using a ROI analysis technique.