Generational shift for clinical application of the QLF system for evaluating tooth wear

No study has quantitatively assessed tooth wear using a clinical quantitative light-induced fluorescence (QLF) system. This study aimed to compare fluorescence parameters (ΔF_wear) between the research QLF system (QLF-D) and clinical QLF system (Qraycam Pro) and evaluate the validity of both systems in detecting dentin exposure from tooth wear.

Thirty-five human molars and premolars were collected. Two blinded examiners conducted evaluations. Images from QLF-D and Qraycam Pro were captured and analyzed by the first examiner to calculate ΔF_wear, representing the maximum fluorescence intensity for occlusal wear. The stage of tooth wear was determined by the second examiner using the tooth wear index (TWI). The area of interest (AOI) was determined as the cusp without defects, such as caries or fractures. Only areas mutually agreed by both examiners were included in analysis. The Kruskal-Wallis test was conducted to assess differences in ΔF_wear between two devices. ROC analysis evaluated the validity of both systems in determining dentin exposure using AUROC.

Thirty-eight AOIs were analyzed. ΔF_wear significantly increased with higher TWI scores. Median ΔF_wear for TWI scores (0, 1, and 2) were 6.9 %, 10.3 %, and 24.8 %, respectively, for QLF-D, and 5.7 %, 7.7 %, and 23.9 %, respectively, for Qraycam Pro. No significant differences in ΔF_wear were observed between QLF-D and Qraycam Pro for any TWI score. The AUROC for both systems was 0.95.

ΔF_wear was comparable between QLF-D and Qraycam Pro and demonstrated high validity in detecting dentin exposure. These findings support the clinical application of the QLF for quantitative tooth wear assessment.