title: The evaluation of endodontic flare-ups and their relationship to various risk factors.
abstract: BACKGROUND
  To evaluate the incidence of flare-ups and identify the risk factors including age, gender, tooth type, number of root canals, initial diagnosis, the type of irrigation regimen, treatment modality and the number of visits, in patients who received root canal treatment from January 2002 to January 2008.
  
  
  METHODS
  Records of 1819 teeth belonging to 1410 patients treated by 1 endodontics specialist during 6-year period were kept. Patient, tooth, and treatment characteristics were evaluated and the relationships between these characteristics and flare-ups were studied. Statistical analysis was carried out by using Pearson Chi-square test, Fisher's Exact test, and Binary Logistic regression analyses.
  
  
  RESULTS
  The incidence of flare-ups was 59 (3.2 %) out of 1819 teeth that received endodontic therapy. Pulpal necrosis without periapical pathosis was the most common indication for flare-up (6 %) (p < 0.01). Teeth undergoing multiple visits had a higher risk of developing flare-ups compared to those with single appointments (OR: 3.14, CI: 1.414-7.009, p < 0.01). There were also no statistically significant differences in the incidence of flare-ups regarding to age, gender, tooth type, number of root canals, treatment modality, and the irrigation solutions that used during the treatment.
  
  
  CONCLUSIONS
  The incidence of flare-up is minimal when teeth are treated in one visit. Absence of a periapical lesion in necrotic teeth is a significant risk factor for flare-ups.
authors.affiliation: Department of Endodontics, Baskent University, School of Dentistry, 82 sok No 26, 06490, Bahcelievler, Ankara, Turkey. eonay@baskent.edu.tr.
authors.forename: Emel Olga
authors.initials: EO
authors.lastname: Onay
authors.affiliation: Department of Endodontics, Baskent University, School of Dentistry, 82 sok No 26, 06490, Bahcelievler, Ankara, Turkey. meteungor@yahoo.com.
authors.forename: Mete
authors.initials: M
authors.lastname: Ungor
authors.affiliation: Department of Biostatistics, Baskent University, School of Medicine, Ankara, Turkey. acyazici@gmail.com.
authors.forename: A Canan
authors.initials: AC
authors.lastname: Yazici
mesh_terms: D006801:Humans; D015994:Incidence; D010149:Postoperative Pain / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D012390:Root Canal Therapy / Q000009:adverse effects; D014098:Toothache / Q000209:etiology