title: Comparison of observer reliability in assessing alveolar bone changes from color-coded with subtraction radiographs.
abstract: OBJECTIVE
  To assess intra- and interobserver agreement on marginal changes in periodontal bone from color-coded compared with subtraction radiographs.
  
  
  METHODS
  Sequential radiographs from patients undergoing periodontal treatment were acquired using direct digital intra-oral radiography. Fifty-one pairs of color-coded and subtraction radiographs were produced and evaluated twice by six dentists for changes in marginal bone. Intra- and interobserver agreement were calculated.
  
  
  RESULTS
  Intra-observer agreement was significantly higher for the color-coded radiographs (P < 0.05). Interobserver agreement was significantly higher for color-coded radiographs at the second (P < 0.001) but not the first (P = 0.34) evaluation.
  
  
  CONCLUSIONS
  Color coding of radiographic differences by means of image addition may be a feasible alternative to the subtraction technique for evaluating periodontal bone changes.
authors: Department of Oral Radiology, Karolinska Institutet, Stockholm, Sweden.
authors: X Q
authors: XQ
authors: Shi
authors: I
authors: I
authors: Eklund
authors: G
authors: G
authors: Tronje
authors: U
authors: U
authors: Welander
authors: H C
authors: HC
authors: Stamatakis
authors: P E
authors: PE
authors: Engström
authors: G N
authors: GN
authors: Engström
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging*; D003116:Color; D006801:Humans; D015588:Observer Variation; D011857:Radiographic Image Interpretation, Computer-Assisted; D019252:Radiography, Dental, Digital / Q000379:methods*; D015203:Reproducibility of Results; D013382:Subtraction Technique