title: Influence of length of root canal obturation on apical periodontitis detected by periapical radiography and cone beam computed tomography.
abstract: BACKGROUND
  The verification of the best length of root canal instrumentation and obturation still is controversial theme in endodontics. The purpose of this study was to determine the influence of length of root canal obturation on apical periodontitis (AP) detected by periapical radiography and cone beam computed tomography (CBCT).
  
  
  METHODS
  A total of 503 root canal obturations were evaluated by using periapical radiography and CBCT. Distances from the radiographic apex to the tip of filling material were measured and classified as close to 2 mm, 1 mm short or beyond apex, and at the apex. Obturations at the apex were associated with AP. Odds ratio, confidence intervals, and chi(2) test were used for statistical analyses.
  
  
  RESULTS
  Periapical radiographs showed that root canal obturations were 1-2 mm short of the apex in 88%, 89.3%, and 95% of the anterior teeth, premolars, and molars, respectively. CBCT images showed obturations had the same length in 70%, 73.7%, and 79% of anterior teeth, premolars, and molars, respectively. The frequency of AP was significantly greater in molars than in the other tooth groups, regardless of diagnostic method. AP was detected more frequently when CBCT was used.
  
  
  CONCLUSIONS
  AP was detected at all lengths of root canal obturation. The analyses of diagnostic methods showed that AP was detected more frequently when CBCT was used.
authors.affiliation: Department of Endodontics, Brazilian Dental Association, Brasília, DF, Brazil.
authors.forename: Marcelo Sampaio
authors.initials: MS
authors.lastname: Moura
authors.forename: Orlando Aguirre
authors.initials: OA
authors.lastname: Guedes
authors.forename: Ana Helena Gonçalves
authors.initials: AH
authors.lastname: De Alencar
authors.forename: Bruno Correa
authors.initials: BC
authors.lastname: Azevedo
authors.forename: Carlos
authors.initials: C
authors.lastname: Estrela
mesh_terms: D054893:Cone-Beam Computed Tomography; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010485:Periapical Periodontitis / Q000000981:diagnostic imaging* / Q000628:therapy*; D011861:Radiography, Dental / Q000379:methods*; D012389:Root Canal Obturation / Q000379:methods*; D019227:Tooth Apex / Q000000981:diagnostic imaging*