Comparison Of Cone-beam Computed Tomography With Different Voxel Resolutions, Periapical Radiography, And Panoramic Imaging For Detection Of Simulated Apical Root Resorption

PART ONECOMPARISON OF CONE-BEAM COMPUTEDTOMOGRAPHY AND PERIAPICAL RADIOGRAPHY FORDETECTING SIMULATED APICAL ROOT RESORPTIONObjective: To compare the diagnostic accuracy between cone-beamcomputed tomography (CBCT) and periapical radiography for detectingsimulated external apical root resorption (EARR) in vitro.Methods: The study sample consisted of160single-rooted premolarteeth for simulating EARR of varying degrees according to4setups: no(intact teeth), mild (cavity of1.0mm in diameter and depth on mesial,distal, buccal, and lingual root surface), moderate (0.4mm,0.8mm,1.2mm,and1.6mm root shortening), and severe (2.4mm,2.8mm,3.2mm, and3.6mm root shortening). Two groups of radiographic images were obtained via CBCT and periapical radiography. The severities for allEARR samples were evaluated blindly by two calibrated observers.McNemar tests were performed to compare the proportions of correctclassification between CBCT and periapical imaging for each degree ofEARR.Results: With CBCT method, the rates of correct classification of no,mild, moderate, and severe EARR were96.3%,98.8%,41.3%, and87.5%,respectively; with periapical radiography method, the rates were82.5%,41.3%,68.8%, and92.5%, respectively. Highly significant differenceswere found between the two imaging methods for detection of mild(P<0.001), moderate (P<0.001), and all EARR (P <0.001). For detectionof all EARR, the sensitivity and specificity values were80%and96.3%for CBCT, compared with71.7%and82.5%for periapical radiography.Conclusions: periapical radiography is more sensitive to morderateroot shortening, whereas CBCT is more reliable than periapicalradiography for detecting mild and all EARR. If a periapical radiograph isalready available to the diagnosis of EARR, CBCT should be used withextreme caution to avoid additional radiation exposure. PART TWOCOMPARISON OF CONE-BEAM COMPUTEDTOMOGRAPHY WITH DIFFERENT VOXEL RESOLUTIONSAND PANORAMIC IMAGING FOR DETECTION OFSIMULATED APICAL ROOT RESORPTIONObjective: The aim of this study was to compare the efficacy ofcone-beam computed tomography (CBCT) with different voxel resolutionsand panoramic radiography in the detection of simulated external apicalroot resorption (EARR) in vitro.Methods: The study sample consisted of160single-rooted premolarsfor simulating EARR of varying degrees according to4setups: no (intactteeth), mild (cavity of1.0mm in diameter and depth on mesial, distal,buccal, and lingual root surface), moderate (0.4mm,0.8mm,1.2mm, and1.6mm root shortening), and severe (2.4mm,2.8mm,3.2mm, and3.6mmroot shortening). These teeth were imaged via CBCT with two differentvoxel sizes (0.2mm and0.3mm) and panoramic radiography. Each rootwas classified according to defect size (no, mild, moderate, and severe) byone calibrated observer using the CBCT and panoramic images. McNemartests were performed to compare the proportions of correct classificationbetween the methods (0.2-mm voxel vs0.3-mm voxel,0.2-mm voxel vspanoramic, and0.3-mm voxel vs panoramic) for each degree of EARR. Results: For panoramic radiography,57.5%of all samples werecorrectly classified, compared with85%for0.2-mm voxel and81.3%for0.3-mm voxel, and the differences were significant (P <0.0001) betweenboth0.2-mm voxel and0.3-mm voxel and panoramic radiography.However, there were no significant differences between0.2-mm voxel and0.3-mm voxel in correct classification for no, mild, severe, and allsamples.Conclusions: CBCT imaging is more reliable than panoramicradiography for detecting EARR. The0.3-mm voxel resolution is thebetter configuration because it offers the same performance as the0.2-mmvoxel resolution in the diagnosis of EARR but with lower patient exposureto x-rays.