title: A Comparison of Radiographic Film Densitometry Using a New Computerized Tool with a Digital Densitometer.
abstract: OBJECTIVE
  The purpose of this study was to develop and test a new tool for radiographic densitometry by combining periapical films and aluminum step wedge.
  
  
  METHODS
  We reviewed 50 Kodak E-speed intraoral films. An aluminum step wedge consisting of 16 steps was constructed. Each step was 1mm×3m×10mm. The step wedge was exposed to varying exposure times, ranging from 0.05 second to 0.5 second, increasing in 0.05 second increments. Films were digitalized after processing and the MATLAB software algorithm was ran subsequently. Density of the films was measured again using a digital densitometer. In order to compare the two imaging techniques, three steps were selected. Output data from the MATLAB algorithm were compared with data obtained from the digital densitometer.
  
  
  RESULTS
  The new method could detect significant differences between subsequent exposure times in step 7, while the densitometer did that in steps 7 and 12. The new method's sensitivity in determining density changes was 5.26%, 84.1% and 93.02% in steps 2, 7, and 12 respectively.
  
  
  CONCLUSIONS
  Our new method has an acceptable sensitivity for determining density changes of at least 7 mmEq/Al.
authors.affiliation: Assistant Professor, Department of Oral and Maxillofacial Radiology, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Hoorieh Bashizadeh
authors.initials: HB
authors.lastname: Fakhar
authors.affiliation: Assistant Professor, Department of Orthodontics, Dental Faculty, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Elham Sadat Emadian
authors.initials: ES
authors.lastname: Razavi
authors.affiliation: Assistant Professor, Department of Orthodontics, Dental Faculty, Hamedan University of Medical Sciences, Hamedan, Iran.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Soheilifar
authors.affiliation: Statistical Consultant, Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
authors.forename: Mohammad Javad
authors.initials: MJ
authors.lastname: Kharazifard
keywords: Aluminum; Densitometry; Image Processing, Computer-Assisted; Phantoms, Imaging