title: Reliability analysis of two methods for measuring active enamel demineralization: An in vitro study.
abstract: OBJECTIVE
  The aim was to evaluate the intra- and inter-examiner reliability of two methods, namely, digital caliper [DC] and computerized image analysis software (Image Tool [IT] version 4.1) for measuring the area of an active enamel demineralization lesion. The effect on that measurement of a window that delimits the lesion was also assessed.
  
  
  METHODS
  Thirty-eight circular artificial enamel demineralization lesions (r = 2 mm) were produced on bovine teeth in vitro, which were then measured three times by three examiners, with and without the presence of a window delimiting the area to be measured. The data were analyzed by the intraclass correlation coefficient (ICC) with 95% confidence interval (CI) and by the Altman and Bland analysis.
  
  
  RESULTS
  The intra-examiner correlation using the IT method showed excellent reproducibility (mean ICC values 0.922-0.970 with the delimiting window and 0.915-0.990 without the window). However, the intra-examiner correlation using the DC method showed comparatively less reproducibility in the measurements (mean ICC values 0.458-0.648 with the delimiting window and 0.378-0.665 without the window). The inter-examiner correlations showed very good reproducibility of the measurements regardless of the presence or absence of the window for both the DC method (0.811-0.846) and IT method (0.953-0.994). However, the latter method showed less variability within the measurements.
  
  
  CONCLUSIONS
  However, statistically no significant difference was found between both methodologies. Nevertheless, computerized image analysis with the Image Tool software demonstrated higher intra- and inter-examiner reliability than the digital caliper method, in estimating the area of the enamel demineralization lesion, regardless of the delimiting window.
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, Dental School, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Camila
authors.initials: C
authors.lastname: Nassur
authors.affiliation: Department of Specific Formation, Dental School, Federal Fluminense University, Nova Friburgo, Brazil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Pomarico
authors.affiliation: Department of Pediatric Dentistry and Orthodontics, Dental School, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Lucianne Cople
authors.initials: LC
authors.lastname: Maia
keywords: Computerized image analysis; dental caries; image processing; observer variation; reproducibility of results; tooth demineralization