title: Periapical radiography and cone beam computed tomography for assessment of the periapical bone defect 1 week and 12 months after root-end resection.
abstract: OBJECTIVE
  Our aim was to compare periapical radiography and cone beam CT (CBCT) for assessment of the periapical bone defect 1 week and 12 months after root-end resection.
  
  
  METHODS
  50 patients (58 teeth) with a persisting apical periodontitis in a root-filled tooth (incisor, canine or premolar) were treated with root-end resection. 1 week and 12 months post-operatively, a CBCT scan (NewTom 3G) and a periapical radiograph (Digora) were obtained. Three observers detected and measured the periapical bone defects on periapical radiographs and CBCT images (coronal and sagittal sections).
  
  
  RESULTS
  1 week post-operatively, a periapical bone defect area was measured in all teeth by all observers. The defect was 10% smaller on periapical radiographs (mean = 12.4 mm2, SD = 8.2) than on the CBCT images measured in the coronal plane (mean = 13.0 mm2, SD = 7.8), a difference which was not statistically significant (P = 0.58). 12 months post-operatively (n = 52), there was considerable variation between the observers' detection of a remaining defect on the periapical radiographs and the CBCT images. The average agreement between the periapical radiograph and the CBCT images in the coronal sections was 67%, and more defects were detected on CBCT than on periapical radiographs.
  
  
  CONCLUSIONS
  On average, the periapical bone defect measured on periapical radiographs was approximately 10% smaller than on coronally sectioned CBCT images 1 week post-operatively. More remaining defects were detected 1 year after periapical surgery on CBCT images than on periapical radiographs, but it is uncertain how this information is related to success or failure after root-end resection.
authors.affiliation: Department of Oral Radiology, School of Dentistry, Faculty of Health Sciences, Aarhus University, Denmark. RChristiansen@odont.au.dk
authors.forename: R
authors.initials: R
authors.lastname: Christiansen
authors.forename: L-L
authors.initials: LL
authors.lastname: Kirkevang
authors.forename: E
authors.initials: E
authors.lastname: Gotfredsen
authors.forename: A
authors.initials: A
authors.lastname: Wenzel
mesh_terms: D000328:Adult; D000368:Aged; D000539:Alveolar Process / Q000000981:diagnostic imaging*; D001047:Apicoectomy; D001641:Bicuspid / Q000000981:diagnostic imaging; D002508:Cephalometry / Q000706:statistics & numerical data; D054893:Cone-Beam Computed Tomography / Q000706:statistics & numerical data; D003481:Cuspid / Q000000981:diagnostic imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007180:Incisor / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D010484:Periapical Granuloma / Q000601:surgery; D010485:Periapical Periodontitis / Q000000981:diagnostic imaging* / Q000601:surgery; D010486:Periapical Tissue / Q000000981:diagnostic imaging*; D016300:Radiography, Bitewing / Q000706:statistics & numerical data; D019252:Radiography, Dental, Digital / Q000706:statistics & numerical data; D012390:Root Canal Therapy; D014945:Wound Healing / Q000502:physiology