Performance of near-infrared light transillumination in the detection of occlusal caries lesions in deciduous teeth

Background: This study compared the performance of near-infrared light transillumination (NILT; DIAGNOcam [DC]) in detecting occlusal caries lesions in deciduous molars with the performance of the International Caries Detection and Assessment System (ICDAS), digital radiographic method (RX) and laser fluorescence (DIAGNOdent pen [LFpen]). Methods: Fifty-seven extracted deciduous molars with no frank cavitation caries lesions were selected. One site per tooth was evaluated twice each by two examiners using all methods. Then, a histological examination was performed using a stereomicroscope. The performance of the methods was assessed with respect to two thresholds: D1 (all visible caries lesions affecting enamel) and D3 (caries lesions extended into dentin). Results: A weighted kappa and intraclass correlation coefficients were calculated for intra- and inter-observer reproducibilities, varying from 0.31 (RX) to 0.89 (LFpen). The intra-observer reproducibility at D1 and D3 thresholds varied from 0.51 (ICDAS) to 0.85 (DC) and from 0.30 (ICDAS) to 1.00 (RX), respectively. The interobserver reproducibility varied from 0.28 (RX) to 0.47 (DC) and from 0.22 (LFpen) to 0.75 (DC), respectively. At the D1 threshold, higher sensitivity and accuracy were found for LFpen (0.76/0.71) and ICDAS (0.65/0.66); and higher specificities were found for RX (0.94), DC (0.79), and ICDAS (0.71). At the D3 threshold, all methods exhibited lower sensitivities (0.13-0.35) and higher specificity, accuracy, and area under the ROC curve values (0.70-1.00). All methods showed a correlation with histological results, especially for ICDAS and DC. Conclusions: NILT technology (DC) and LFpen exhibited similar performance for the detection of occlusal caries lesions in deciduous molars when compared with ICDAS criteria.