Accuracy of Digital Periapical Radiography and Cone-beam Computed Tomography for Diagnosis of Natural and Simulated External Root Resorption

Introduction

The aim of this study was to compare the sensitivity and specificity of digital periapical radiography and cone-beam computed tomographic (CBCT) imaging in the detection of natural and simulated external root resorptions (ERRs) with micro–computed tomographic (micro-CT) imaging as the reference standard.

Methods

One hundred twenty-six teeth were scanned using the SkyScan 1172 micro-CT scanner (Bruker microCT, Kontich, Belgium), and the images were evaluated using NRecon software (Bruker microCT). After micro-CT imaging, the teeth were divided into 3 groups: control, 42 teeth that did not present any ERR cavities; natural, 42 teeth that presented 1 or more ERR cavities; and artificial, 42 teeth without ERRs but perforations were created to simulate the cavities. Ortho-, mesio-, and distoradial digital periapical radiographs and CBCT images were obtained, and the images were evaluated by 2 double-blinded qualified radiologists.

Results

The sensitivities and specificities for the radiographic and tomographic methods were 78.18% and 97.27% and 59.52% and 97.62%, respectively. Within the individual groups, both methods had lower sensitivity and specificity for natural and artificial resorptions, and the differences were statistically significant.

Conclusions

CBCT imaging was the best method for the detection of ERRs. Only 74.5% of natural ERR gaps were observed on the digital periapical radiographs and 94.5% on CBCT imaging; in the artificial group, this number increased to 81.8% and 100%, respectively. The configuration of the natural ERR gaps is different from those artificially simulated and is much more difficult to observe.