Can ultrasonography be used to detect root perforation? An in vitro study

This study assessed the usability of ultrasonography in detecting root canal perforations. The buccal side of incisor root were perforated. The actual lengths up to the perforation site were measured by visualisation of the tip of a file. Specimens were embedded in gypsum, and it was scraped to simulate bone resorption. Resorption cavities were filled with ultrasound gel. Measurements were taken by advancing a file through the canal until the tip became visible in the ultrasound image. 3D scans were obtained using cone-beam computed tomography (CBCT) and the distance between the coronal point of the resorption cavity and the reference point was measured. The actual distance of the resorption cavity from the reference point varied 6-10.6 mm. The same distances were measured via ultrasound as 5.7-10.9 mm, while measured using CBCT 6-10.5 mm. No significant differences were found. Ultrasonography shows promise for detecting root perforations, however further research is needed.