title: A clinical study on single-visit root canal retreatments on consecutive 173 patients: frequency of periapical complications and clinical success rate.
abstract: OBJECTIVE
  This study assessed the outcome measures of single-visit root canal retreatments and frequency of periapical complications considering preoperative, intraoperative and postoperative factors.
  
  
  METHODS
  Between November 2011 and December 2012, in 173 patients, a total of 234 endodontically treated teeth were retreated in a single appointment by one experienced endodontist. Five teeth were extracted and 119 teeth were lost to follow-up yielding to 110 teeth (47 %) to be examined by two calibrated examiners for the outcome of healing (periapical index score-PAI ≤2; no signs or symptoms) or non-healing (presence of apical periodontitis-PAI >2; signs or symptoms). Preoperative, intraoperative and postoperative factors were evaluated for their association with the outcome. Data were analysed using Fisher's exact and Fisher-Freeman Halton tests for bivariate analysis to identify potential outcome predictors. Logistic regression models were used for multivariate analysis to determine significant outcome predictors.
  
  
  RESULTS
  Mean observation time was 29 months. Follow-up assessment revealed 100 teeth (90.9 %) as healed and 10 teeth (9.1 %) non-healed. Age, gender, tooth type and preoperative (pain, periodontal defects, root filling density and length), intraoperative (sealer extrusion) and postoperative (type of coronal restorations) factors did not significantly affect the outcome (p > 0.05). Preoperative periradicular lesions with diameters less than 5 mm presented significantly better outcome than larger lesions (p < 0.05; odds ratio (OD) 6; 95 % CI 1.45-24.85). Logistic regression model showed an increased risk of non-healing for the parameter of preoperative periradicular lesions with diameters larger than 5 mm (OD 6.42; 95 % CI 1.51-27.27).
  
  
  CONCLUSIONS
  Single-appointment root canal retreatments presented a favourable success rate. Only preoperative lesion size had a significant effect on the outcome where the lesions smaller than 5 mm performed significantly better healing.
  
  
  CONCLUSIONS
  Single-appointment root canal retreatments could be considered as a viable treatment option for orthograde retreatment cases with periradicular lesion size smaller than 5 mm.
authors.affiliation: School of Dentistry, Department of Endodontics, Istanbul Medipol University, Atatürk Bulvarı No:27, Unkapanı, Fatih, 34083, Istanbul, Turkey. tfeyuboglu@yahoo.com.
authors.forename: Tan Firat
authors.initials: TF
authors.lastname: Eyuboglu
authors.affiliation: School of Dentistry, Department of Endodontics, Istanbul Medipol University, Istanbul, Turkey.
authors.forename: Kezban
authors.initials: K
authors.lastname: Olcay
authors.affiliation: Dental Materials Unit, Centre for Dental and Oral Medicine, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, University of Zürich, Plattenstrasse 11, CH-8032, Zürich, Switzerland.
authors.forename: Mutlu
authors.initials: M
authors.lastname: Özcan
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement; D011183:Postoperative Complications / Q000453:epidemiology*; D019233:Retreatment; D012189:Retrospective Studies; D012390:Root Canal Therapy / Q000379:methods*; D019553:Tooth, Nonvital / Q000628:therapy*; D016896:Treatment Outcome; D014421:Turkey / Q000453:epidemiology
keywords: PAI scores; Periapical complications; Periapical lesion; Root canal retreatment; Single-appointment endodontic therapy