(PO133) Assessing Obturation Voids Between Radicular Dentin and Single Cone Gutta-Percha Using CBCT in Root Canal Prepared Teeth

Abstract: Oral radiologists are asked to identify the presence of voids in obturation with CBCT. Voids allow for biofilms and corresponding virulence factors that can result in apical periodontitis. Determining voids in CBCT is difficult due to beam hardening and blooming artifacts. Micro CT is considered the gold standard for determining the morphology of root canals. The aim is to determine the level of accuracy and agreement of CBCT in determining if a void is present between the gutta-percha and the root canal wall. Twenty-five mandibular incisors with a single canal were decoronated and prepared to a 45.04 taper with K3xF rotary files 1 mm short of the apex. The working length was recorded, and a gutta-percha cone of 45.04, 40.04, 35.04, 30.04, 25.04, 20.04, 15.04 was placed and scanned with a CBCT unit. This resulted in 384 CBCT scans. Voids are present in every image unless a 45.04 cone is present. Micro-CT scans were completed to provide the ground truth if voids are present. Four calibrated examiners viewed the scans and were asked to determine their level of certainty as to whether or not a void was present between the gutta-percha cone and the canal wall. The statistical analysis was performed. The tests included the Kappa coefficient, ANOVA, Tukey’s post hoc test, chi-square, and a ROC curve was produced. Results are pending. Potential conclusion is that CBCT shows poor sensitivity in detecting true voids between the gutta-percha cone and root canal walls and that observer agreement is low.