title: Accuracy of zoomed digital image in the detection of periodontal bone defect: in vitro study.
abstract: OBJECTIVE
  (1) To evaluate the intraobserver agreement related to image interpretation and (2) to compare the accuracy of 100%, 200% and 400% zoomed digital images in the detection of simulated periodontal bone defects.
  
  
  METHODS
  Periodontal bone defects were created in 60 pig hemi-mandibles with slow-speed burs 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm and 3.0 mm in diameter. 180 standardized digital radiographs were made using Schick sensor and evaluated at 100%, 200% and 400% zooming. The intraobserver agreement was estimated by Kappa statistic (kappa). For the evaluation of diagnostic accuracy receiver operating characteristic (ROC) analysis was performed followed by chi-square test to compare the areas under ROC curves according to each level of zooming.
  
  
  RESULTS
  For 100%, 200% and 400% zooming the intraobserver agreement was moderate (kappa=0.48, kappa=0.54 and kappa=0.43, respectively) and there were similar performances in the discrimination capacity, with ROC areas of 0.8611 (95% CI: 0.7660-0.9562), 0.8600 (95% CI: 0.7659-0.9540), and 0.8368 (95% CI: 0.7346-0.9390), respectively, with no statistical significant differences (chi2-test; P=0.8440).
  
  
  CONCLUSIONS
  A moderate intraobserver agreement was observed in the classification of periodontal bone defects and the 100%, 200% and 400% zoomed digital images presented similar performances in the detection of periodontal bone defects.
authors.affiliation: Rua Humaitá, 1680, 14801-903, Araraquara, São Paulo, Brazil.
authors.forename: J A N D
authors.initials: JA
authors.lastname: de Morais
authors.forename: C E
authors.initials: CE
authors.lastname: Sakakura
authors.forename: L C M
authors.initials: LC
authors.lastname: Loffredo
authors.forename: G
authors.initials: G
authors.lastname: Scaf
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging*; D000818:Animals; D016009:Chi-Square Distribution; D008336:Mandibular Diseases / Q000000981:diagnostic imaging; D015588:Observer Variation; D012372:ROC Curve; D011858:Radiographic Magnification / Q000379:methods; D019252:Radiography, Dental, Digital / Q000379:methods*; D015203:Reproducibility of Results; D013552:Swine