Evaluation of Bone Level Using Periapical Radiography and CBCT: A Prospective Observational Accuracy Study

Radiographic assessment plays an important role in the diagnosis of periodontal disease. However, intraoral radiographs often underestimate interproximal bone level. Cone beam CT (CBCT) has been shown to outperform 2D radiography in the detection of furcation involvement, but research on bone level measurements is scarce. This study aimed to assess the accuracy of CBCT and intraoral periapical radiographs (PARX) as diagnostic tools for evaluating bone morphology compared to clinical measurements in an open field setting. This prospective observational diagnostic accuracy study consisted of 29 patients who were planned for periodontal surgery. Pre-surgical assessment consisted of PARX and CBCT compared to open field measurements, using a periodontal probe prior to any bone correction. The following parameters were evaluated: CEJ-BD (cementoenamel junction-base of the defect), AC-BD (alveolar crest–base of the defect), furcation involvement, and bone morphology (angular vs. horizontal). Twenty-nine patients were included, and a total of 173 interproximal sites were assessed. The ICC for the primary variable (CEJ-BD) indicated poor reliability for PARX (0.47), while CBCT showed moderate reliability (0.63). For infrabony measurements, ICC values indicated poor reliability for PARX (0.38) and moderate reliability for CBCT (0.56). Regarding furcation involvement, periapical radiography showed fair agreement (κ = 0.32), whereas CBCT demonstrated substantial agreement (κ = 0.72). Bone morphology assessment showed slight agreement for PARX (κ = 0.11) and fair agreement for CBCT (κ = 0.40). CBCT provides more consistent and reliable assessments of bone level, defect morphology and furcation involvement compared to conventional periapical radiographs.