Evaluation of Periodontal Infrabony Defect Topography via CBCT and Comparisons with Direct Intrasurgical Measurements.

Two-dimensional periapical radiographs (PAs) only offer limited information regarding three-dimensional periodontal infrabony defects. In contrast, cone beam computed tomography (CBCT) enables visualization of the entire defect morphology. This study aimed to evaluate the agreement between CBCT and direct intrasurgical measurements (ISs) regarding the characteristics of infrabony defects, including measurements of defect depth, width, the type of defect (one-wall, two-wall, three-wall), and defect extension. Intrasurgical and radiographic assessments were performed by two calibrated examiners on 26 infrabony defects in 17 patients who underwent periodontal surgery. The defect depth, width, type, and extension were compared between intrasurgical observations and PA or CBCT findings. The CBCT assessment was performed mainly using axial reconstructions. Angle measurements were compared between CBCT and PAs. The mean differences between CBCT and intrasurgical measurements were -0.11 ± 0.49 mm for depth and -0.07 ± 0.41 mm for width, with no significant differences. The ICC values were 0.938 and 0.923 for depth and width, respectively. The mean difference in width between PAs and ISs was significantly different (-0.36 ± 0.73 mm; = 0.002). CBCT demonstrated high agreement with intrasurgical observations for defect type (κ = 0.819) and defect extension (κ = 0.855), while lower agreements were found for PAs. CBCT is a valid assessment modality for infrabony defects. It demonstrated strong agreement with ISs-as the gold standard-for depth and width measurements, and its agreement with ISs regarding defect type and extension appeared to surpass that of PAs.