Comparative Study Between 0.125mm, 0.35mm and 0.75mmVoxel Sizes of Cone Beam Computed Tomography in Diagnosis of Secondary Caries Lesions Under Composite Restorations (An In vitro Study)

The aim of this study was to assess the diagnostic accuracy of Cone Beam Computed Tomography (CBCT) with different voxel sizes in detection of simulated recurrent caries beneath composite restoration. In this study, a total of 40 proximal slots of class II cavities were prepared on 40 extracted human premolars and molars. Then, 20 teeth were randomly selected out of these sample and artificial carious lesions were created on these teeth by a round diamond bur no .2(study group). All cavities were restored by using composites resin and radiographed with CBCT unit (Cranex 3D) using 5x5mm field of view at three voxel sizes 0.35mm, 0.125mm, 0.75mm. Intra- and inter-observer agreements were calculated with Kappa statistics (κ). The area under the receiver operating characteristic (ROC) curve was used to evaluate the diagnostic ac curacy. The AUCs value for CBCT with voxel sizes 0.35mm, 0.125mm, 0.75mm was 0.983 ,0.900,0.817, respectively. The kappa value for inter-observer agreement was 0.993,0.989,0.938; respectively. Diagnostic Accuracy of CBCT was high in detecting the simulated small secondary proximal caries under composite restoration, voxel size 0.125mm can be used to detect caries lesions with adequate accuracy and the least patient exposure dose.