An in vitro comparison of different caries-detection methods in primary-molars

The early and accurate detection of occlusal caries in primary molars is critical to prevent its progression, as primary teeth are more susceptible to rapid carious development. This study aimed to evaluate and compare the diagnostic performance of various caries detection methods, in detecting occlusal caries in primary molars.

A total of 88 freshly extracted primary molar teeth were included in this in vitro study. The teeth were assessed using four diagnostic methods: International Caries Detection and Assessment System II (ICDAS), Midwest Caries I.D (MW), DIAGNOdent pen (LFpen) and Quantitative-Light-Induced-Fluorescence (QLF). The performance of the method was evaluated by two examiners at two separate time points. Sensitivity, specificity, and the area under the receiver operating characteristic curve (AUC) were calculated for both the enamel (D1) and dentin (D3) thresholds. Histological evaluation was performed as the gold standard for comparison. Interexaminer and intraexaminer reproducibility were assessed using Cohen's weighted kappa and intraclass correlation coefficients.

At the enamel caries threshold (D1), MW achieved the highest sensitivity (61.7-76.6%), while QLF exhibited the highest specificity (92.5%). For dentin caries (D3), LFpen had the highest sensitivity (p < 0.05), whereas ICDAS achieved 100% specificity. LFpen demonstrated the best overall diagnostic accuracy, with AUC values ranging from 0.823 to 0.875. Interexaminer reproducibility was highest for LFpen (ICC: 0.719-0.869), followed by ICDAS (kappa: 0.584-0.932).

LF pen showed the highest overall AUC and the greatest sensitivity at the D3 threshold. At the D1 threshold, Midwest Caries ID achieved the highest sensitivity, whereas QLF yielded the highest specificity, minimizing false positives. ICDAS remains a practical, cost-effective option for routine clinical use.