The Effect of Magnification for Detecting Low and High Internal Root Resorption in Single-Root Teeth in Cone-Beam Computed Tomography (An in-Vitro Study)

Early detection of Internal Root Resorption (IRR) is considered a challenging issue in endodontics. Processing filters are used to facilitate image interpretation either in diagnostic or treatment procedures. The aim of this study was to investigate the effect of magnification changes on the detection of IRR in Cone Beam Computed Tomography (CBCT) images.

In this study, a total of 34healthy single-canal & rooted teeth were split mesiodistally through their medial canal using an ultra thin metal saw (1 mm). Then, absorption cavities were artificially created in both low and high degree absorption forms. CBCT images with three different magnification levels of 50, 100 and 150 were analyzed by one  radiologist and one endodontist before and after artificial cavity creation. Gathered data were analyzed by MacNemar and Kappa tests using SPSS statistical software. Overall accuracy was calculated by the Area Under the Curve (AUC).

Calculated percentages of sensitivity, specificity and overall accuracy for the first(with high image magnification) and second (with low image magnification) observer were the same (100%, 88.24% and 94%, respectively) and there was no significance difference between low and high degree of resorption and also different magnifications with reality.

Depending on its method of application, all levels of magnification for CBCT images are suitable in diagnosis of IRR.