Accuracy of Near-Infrared Imaging in Detection of Proximal Caries Lesions in Deciduous Molars: An in vitro Study.

INTRODUCTION

The aim of this in vitro study was to evaluate the accuracy of near-infrared imaging (NIRI) generated by the iTero Element 5D scanner for detecting proximal caries lesions in deciduous molars, compared with visual inspection (VI), bitewing (BW) radiography, and histological examination (reference standard).

METHODS

Sound deciduous molars and those with caries lesions (ICDAS 0 to 5) on the proximal surface were included, while teeth with marginal crest breakdown, restoration on the mentioned surfaces, or extensive dentin resorption were excluded. A total of 182 deciduous molars, divided into 91 pairs of first and second molars, were evaluated by two blinded examiners. Two distinct thresholds were considered for the assessment of caries detection methods: enamel lesion (D1) and dentin lesion (D3). Specificity, sensitivity, accuracy, and area under the ROC curve (AUC) were calculated for each method in the statistical analysis.

RESULTS

All evaluated methods demonstrated high specificity at D1, with 1.00 for VI and 0.95 for NIRI and BW, and at D3, 0.99 for BW and 0.98 for NIRI and VI, without statistical differences. The sensitivity and accuracy of NIRI at D1 were 0.44 and 0.55, while those of VI were 0.46 and 0.58, and of BW were 0.60 and 0.68, respectively. And sensitivity and accuracy of NIRI at D3 were 0.14 and 0.69, while those of VI were 0.37 and 0.77, and of BW were 0.51 and 0.82, respectively. No difference in sensitivity and accuracy was observed between NIRI and VI at D1 (p = 0.589); however, NIRI presented the lowest accuracy at D3. At D1, no statistical difference was observed between the AUC of BW and VI (p = 0.1124), nor between NIRI and VI (p = 0.2523). However, at D3, statistical differences were observed between the AUCs of the three evaluated methods: VI versus NIRI (p = 0.0005), VI versus BW (p = 0.0281), and NIRI versus BW (p < 0.0001).

CONCLUSION

NIRI showed accuracy comparable to VI at the D1 threshold but was less effective than BW radiography at both D1 and D3 thresholds.