CBCT Accuracy in Detecting Interproximal Caries with and without Amalgam Restorations

Objective: To evaluate the diagnostic accuracy of cone-beam computed tomography (CBCT) in detecting interproximal caries in human extracted teeth with and without amalgam restorations. Materials and Methods: This study included 200 human posterior extracted teeth. One hundred teeth had proximal amalgam restorations, and 100 were unrestored. All specimens were scanned using Planmeca ProMax 3D CBCT (FOV 8×8 cm; voxel size 0.2 mm). Caries presence was determined histologically (gold standard) and scored using ICDAS criteria. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy were calculated. Logistic regression assessed the influence of amalgam on diagnostic performance. Results: CBCT demonstrated lower sensitivity and specificity in teeth with amalgam compared to unrestored teeth. Beam-hardening artifacts significantly influenced diagnostic reliability (p < 0.05). Conclusion: Although CBCT shows acceptable diagnostic performance for interproximal caries detection, the presence of amalgam restorations moderately reduces accuracy. Conventional bitewing radiography should remain the primary modality when metallic restorations are present.