Comparative assessment of CBCT and digital radiography in quantifying periapical pathology (in vitro study)

To compare the diagnostic accuracy of phosphor plate-based digital periapical radiography (DPR) and CBCT in quantifying periapical lesions compared to the reference standard.

This in vitro study included 45 premolar teeth with simulated periapical lesions created in dry human mandibles. The lesions were categorized into three groups according to size. All specimens were imaged using DPR with the paralleling technique (70-80kVp, 8mA, 0.16-0.32s). CBCT imaging was performed using the i-CAT Next Generation system (120kVp, 5mA, 26.9s, 0.25mm voxel size). Lesion lengths obtained from both imaging modalities were compared with the actual lesion dimensions (reference standard) to assess diagnostic accuracy. Intra-examiner reliability was evaluated.

Group I's mean lesion length was 1.2mm, Group II's was 1.5mm, and Group III's was 1.8mm. In comparison to the reference standard, PR frequently overestimated the length of lesions. CBCT, on the other hand, showed better accuracy, and greater consistency. A propensity to underestimate minor lesions was indicated by the mean CBCT measurement of 1.07 ± 0.20mm at 1.2 mm group (p = 0.020). At 1.5mm, CBCT assessed 1.72 ± 0.19mm (p = 0.001) while no significant difference observed at 1.8mm (p = 0.065).

While CBCT is more reliable than PR, its precision is influenced by lesion size, performing most accurately with larger periapical pathologies.

Periapical radiography should be interpreted with caution when assessing periapical pathology, as it may lead to overestimation of lesion size. In contrast, CBCT can be regarded as the reference standard, especially for lesions larger than 1.5mm.