Histological validation of ICDAS II and radiological assessment of occlusal carious lesions in permanent teeth.

The International Caries Detection and Assessment System (ICDAS) was introduced for a detailed evaluation of dental caries. The aim of the present study was to compare the ICDAS scores and radiologically evaluated caries depths to the histologically evaluated carious lesions in permanent teeth. 84 freshly extracted human teeth were included. Visual examination and scoring of the occlusal aspect were performed according to the ICDAS II criteria after completing a respective e-learning programme to support training in the use of ICDAS. Bucco-lingual digital X-ray images of the teeth were taken. Specimens were then fixed in formalin and embedded in a photocuring one-component methacrylate-based resin. Longitudinal sections were cut and stained with rhodamine B, fuchsin and acetic light green dye to assess the caries extension by light microscopic analysis. Assessing ICDAS II scores and histological findings, a rank correlation coefficient of r = 0.890 could be found. ICDAS II/radiology and histology/radiology showed correlation coefficients of r = 0.658 and 0.661, respectively. Evaluating receiver operating characteristic (ROC) curves, no exact predictability could be found for caries lesions in enamel for both ICDAS II and radiological evaluation. Focussing on deep dentin lesions, values of 0.940 (ICDAS II) and 0.845 (radiology) showed high predictability with respect to the histologically observed caries extension. The present study indicates an acceptable validity of the ICDAS II criteria when applied to permanent teeth. Especially, dentin lesions can be reliably detected. Thus, ICDAS assessment provides the possibility of reducing X-ray exposure for caries detection.