title: Radiographic parameters of quality of root canal fillings and periapical status: a retrospective cohort study.
abstract: BACKGROUND
  The aim of this study was to radiographically evaluate the relationship between the quality parameters of root canal fillings (apical extension, homogeneity, and taper) and periapical status. In addition, groups of teeth and complicating factors of endodontic treatment were assessed.
  
  
  METHODS
  This retrospective cohort study assessed the quality and periapical status of root-filled canals in a 4- to 7-year follow-up period. Each parameter was dichotomized into ideal and altered conditions. A root-filled canal with an ideal condition for all 3 parameters was considered perfect, whereas the loss of 1 or more ideal conditions defined satisfactory or deficient fillings, respectively. The periapical statuses at baseline and follow-up were classified as normal, slight widening of the apical periodontal ligament, or periapical lesion.
  
  
  RESULTS
  A total of 291 root-filled canals were evaluated. The prevalence of perfect, satisfactory, and deficient fillings was 54.6%, 37.5%, and 7.9%, respectively (P < .05). The periapical status at follow-up showed normal, slight widening of the apical periodontal ligament, or periapical lesion in 69.8%, 19.2%, and 11% of the roots, respectively (P < .05). The multivariate logistic regression showed that only preoperative periapical lesions (odds ratio, 2.99; 95% confidence interval, 1.27-7.03) and altered tapers (odds ratio, 3.73; 95% confidence interval, 1.51-9.24) were significantly associated with postoperative periapical lesions.
  
  
  CONCLUSIONS
  Radiographic parameters of the quality of root-filled canals showed a significant relationship with the periapical status. Nevertheless, an altered taper was the main factor associated with the maintenance or development of periapical lesions after 4- to 7-year follow-up period.
authors.affiliation: Faculdade de Odontologia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina, MG, Brazil.
authors.forename: Suelleng Maria Cunha
authors.initials: SM
authors.lastname: Santos
authors.forename: Janir Alves
authors.initials: JA
authors.lastname: Soares
authors.forename: George Moreira
authors.initials: GM
authors.lastname: Costa
authors.forename: Manoel
authors.initials: M
authors.lastname: Brito-Júnior
authors.forename: Allyson Nogueira
authors.initials: AN
authors.lastname: Moreira
authors.forename: Cláudia Silami
authors.initials: CS
authors.lastname: de Magalhães
mesh_terms: D016009:Chi-Square Distribution; D015331:Cohort Studies; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D015588:Observer Variation; D010483:Periapical Diseases / Q000000981:diagnostic imaging* / Q000209:etiology / Q000628:therapy; D010513:Periodontal Ligament / Q000000981:diagnostic imaging; D011787:Quality of Health Care; D011861:Radiography, Dental; D012189:Retrospective Studies; D012389:Root Canal Obturation / Q000009:adverse effects / Q000592:standards*; D018709:Statistics, Nonparametric