Endodontic Outcome Predictors Identified with Periapical Radiographs and Cone-beam Computed Tomography Scans

Introduction: The outcome predictors identified with data from periapical radiographs (PA) and cone-beam computed tomography (CBCT) scans might not be the same. This retrospective study evaluated various factors that might affect the outcome of root canal therapy. Methods: In total, 115 teeth (143 roots) with vital pulps were endodontically treated and followed up 2 years after treatment. Multivariate logistic regression was performed on the data from PA or CBCT to analyze outcome predictors. Results: At recall, PA detected periapical lesions in 18 roots (12.6%), as compared with 37 on CBCT images (25.9%). The length and density of root filling determined by PA and CBCT were often different (p < .001). Overall, 20 of the 25 short root fillings (80%) diagnosed by PA appeared as flush fillings on CBCT images. PA revealed 23 root fillings (16.1%) with voids, as compared with 66 on CBCT images (46.2%). When findings from PA were analyzed, density and apical extent of root filling were identified as predictors (p < .05). When findings from CBCT were analyzed, density of root filling and quality of coronal restoration influenced the outcome significantly (p <= .001), whereas gender, tooth type, root curvature, number of visits, CBCT-determined apical extent of root filling, and use as abutment did not (p > .1). Conclusions: Treatment outcome, length and density of root fillings, and outcome predictors as determined with CBCT scans might not be the same as corresponding values determined with PA. (J Endod 2011;37:326-331)