Comparison of images from digital intraoral receptors and cone beam computed tomography scanning for detection of voids in root canal fillings: an in vitro study using micro-computed tomography as validation

Objective. To compare the diagnostic value of six intraoral digital receptors and a cone beam computed tomography scanning system for detection of voids in root fillings. Methods. Sixty-seven root-filled roots with oval and ribbon-shaped canals were included. Three standardized radiographic examinations were performed for each root with six intraoral digital receptors. Further, the roots were examined using CBCT. Four observers measured the extension of voids in all images. The true extension of voids was recorded in cross-sectional images from micro-computed tomography scans (micro-CT). The proportion of voids observed in the radiographic image validated against micro-CT was calculated for each system. Results. All intraoral receptors underestimated the extension of voids, and few false positives were recorded. CBCT resulted in a higher proportion of correctly observed voids, but with several false-positive recordings. Conclusions. The diagnostic value differed little among the six intraoral systems. CBCT overestimated in many cases the proportion of voids in root fillings.