Quantitative comparison of enamel-dentin and dentin-pulp distances between cone-beam computed tomography and histological sections: An ex vivo study.

BACKGROUND/PURPOSE: Cone-beam computed tomography (CBCT) has become an essential imaging tool in dentistry for evaluating internal tooth morphology. However, its quantitative accuracy in representing true enamel-dentin (E-D) and dentin-pulp (D-P) distances remains uncertain. This study aimed to compare CBCT-derived measurements with histological references and to assess depth-dependent discrepancies across tooth sections. MATERIALS AND METHODS: A total of 18 extracted human teeth were sectioned bucco-lingually and analyzed using both CBCT and histological microscopy. For each tooth, three representative slices were selected: the first and last slices containing pulp tissue, and one at the midpoint. E-D and D-P distances were measured digitally and compared between modalities using paired t-tests, correlation analysis, and Bland-Altman plots. RESULTS: CBCT consistently overestimated E-D distances compared with histology, particularly near the pulp chamber, whereas D-P differences showed greater variability. Weak to moderate linear correlations were observed between modalities (E-D: r = 0.45; D-P: r = 0.34). Bland-Altman analysis indicated a mean bias of +0.26 mm for E-D and -0.09 mm for D-P, suggesting a trend toward systematic overestimation in enamel-dentin regions and inconsistent deviation patterns in deeper dentin-pulp zones. CONCLUSION: While CBCT provides clinically acceptable accuracy in quantifying intra-tooth structures, it tends to overestimate enamel-dentin thickness in deeper regions. These findings underline the need for refined imaging calibration to enhance quantitative reliability in endodontic and restorative applications.