Comparative assessment of occlusal and proximal caries detection using an intraoral scanner and panoramic radiography

Recently, fluorescence-based caries detection has been integrated into intraoral scanners as a radiation-free adjunctive tool for caries assessment. However, evidence regarding the agreement of these systems with conventional diagnostic methods remains limited. Therefore, the aim of this retrospective study was to evaluate the agreement among panoramic radiography, the fluorescence-based caries detection mode of the TRIOS 5 intraoral scanner, and ICDAS (International Caries Detection and Assessment System)-based on-screen assessment of digital intraoral scan images in the detection and classification of occlusal and approximal carious lesions.

Sixty patients aged 16-45 years who met the inclusion criteria were included. Archived panoramic radiographs and TRIOS 5 (3Shape TRIOS A/S, Copenhagen, Denmark) intraoral scan records were retrospectively evaluated. Permanent teeth were analyzed. Panoramic radiographic findings were classified as Score 0 (sound), Score 1 (initial lesion), and Score 2 (deep dentin lesion). The fluorescence-based caries detection mode of the TRIOS 5 classified lesions as initial, moderate/extensive, or insufficient scan. Archived intraoral scan images were also visually assessed using an on-screen ICDAS-based protocol. Inter-method agreement was evaluated using Gwet's AC1/AC2, Fleiss' kappa, and Krippendorff's alpha coefficients. McNemar's test and complementary mixed-effects logistic regression were used for pairwise comparisons. Sensitivity, specificity, predictive values, likelihood ratios, and diagnostic odds ratios were also calculated. Statistical significance was set at p < 0.05.

The fluorescence-based caries detection mode of the TRIOS 5 classified a higher proportion of teeth as having occlusal and enamel-limited lesions, whereas panoramic radiography classified a higher proportion as having approximal and deep dentin lesions. Agreement between TRIOS 5 and the on-screen ICDAS-based assessment was higher than that between TRIOS 5 and panoramic radiography, although overall agreement among the three methods remained low. In subgroup analyses, agreement between TRIOS 5 and the visual assessment was higher for molars than for premolars.

The fluorescence-based caries detection mode of the TRIOS 5 intraoral scanner provided diagnostic information complementary to panoramic radiography. Further prospective studies using independent reference standards are required to confirm its clinical performance.