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Four-year Outcome of Nonsurgical Root Canal Retreatment Using Cone-beam Computed Tomography: A Prospective Cohort
Ming-Ming Zhang1, Gao-Feng Fang1, Xiao-Tong Chen1
1Department of Cariology and Endodontology, Peking University School and Hospital of Stomatology and National Clinical Research Center for Oral Diseases and National Engineering Laboratory for Digital and Material Technology of Stomatology and Beijing Key Laboratory of Digital Stomatology, Beijing, China.
Introduction:
The purpose of this prospective study was to investigate the 4-year outcome and prognostic factors of nonsurgical root canal retreatment determined by measuring the volumetric change of periapical radiolucencies on cone-beam computed tomographic (CBCT) scans.
Methods:
Ninety-seven endodontically treated teeth from 80 patients diagnosed as apical periodontitis and indicated for root canal retreatment were included. Retreatment was performed by 7 endodontic specialists using a standardized treatment protocol. The teeth were reexamined clinically and radiographically 48-67 months after retreatment. The volume of preoperative and postoperative periapical radiolucencies on CBCT images was independently measured by 2 examiners. Radiographic outcome is presented in 4 categories: absence, reduction, enlargement, or unchanged. Reduction or enlargement was determined when the volumetric change of radiolucency was 20% or more. Multivariate logistic regression was performed for predictor analysis.
Results:
Sixty-two teeth (63.9%) from 50 patients returned for follow-up. Fifty-eight teeth were included in the prognostic analysis, all of which were symptom free. The 4 remaining teeth that had been extracted because of fracture were excluded. The total volume of periapical radiolucencies at 4 years postoperatively decreased by 94.6% compared with that preoperatively (P < .001), with an average reduction of 83.4% (95% confidence interval, 69.2%-97.5%). The periapical radiolucencies were determined as absence in 44 teeth (75.9%), reduction in 10 teeth (17.2%), unchanged in 1 tooth (1.7%), and enlargement in 3 teeth (5.2%). Tooth type was identified as an outcome predictor (P < .05).
Conclusions:
The 4-year outcome of endodontic retreatment is predictable, with a significant volumetric reduction in periapical radiolucencies.
