title: Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: an in vitro study.
abstract: OBJECTIVE
  This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth.
  
  
  METHODS
  Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison.
  
  
  RESULTS
  There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm (IC(95%):6.04-6.54) and 6.79 mm (IC(95%):6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64mm(IC(95%):6.40-6.89) and 6.79mm(IC(95%):6.45-7.11), respectively.
  
  
  CONCLUSIONS
  The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.
authors.affiliation: Department of Diagnosis and Surgery, Araraquara Dental School, Universidade Estadual Paulista, Sao Paulo, Brazil.
authors.forename: Rafael Scaf
authors.initials: RS
authors.lastname: de Molon
authors.forename: Juliana Aparecida Najarro Dearo
authors.initials: JA
authors.lastname: Morais-Camillo
authors.forename: Celso Eduardo
authors.initials: CE
authors.lastname: Sakakura
authors.forename: Mauricio Goncalves
authors.initials: MG
authors.lastname: Ferreira
authors.forename: Leonor Castro Monteiro
authors.initials: LC
authors.lastname: Loffredo
authors.forename: Gulnara
authors.initials: G
authors.lastname: Scaf
keywords: Alveolar Bone Loss; Digital Radiography, Dental; Radiographic Image Enhancement