title: Evaluation of 4 Commercial Viewing Devices for Radiographic Perceptibility and Working Length Determination.
abstract: BACKGROUND
  This study compared images displayed on 1 desktop monitor, 1 laptop monitor, and 2 tablets for the detection of contrast and working length interpretation, with a null hypothesis of no differences between the devices.
  
  
  METHODS
  Three aluminum blocks, with milled circles of varying depth, were radiographed at various exposure levels to create 45 images of varying radiographic density. Six observers viewed the images on 4 devices: Lenovo M92z desktop (Lenovo, Beijing, China), Lenovo Z580 laptop (Lenovo), iPad 3 (Apple, Cupertino, CA), and iPad mini (Apple). Observers recorded the number of circles detected for each image, and a perceptibility curve was used to compare the devices. Additionally, 42 extracted teeth were imaged with working length files affixed at various levels (short, flush, and long) relative to the anatomic apex. Observers measured the distance from file tip to tooth apex on each device. The absolute mean measurement error was calculated for each image. Analysis of variance tests compared the devices. Observers repeated their sessions 1 month later to evaluate intraobserver reliability as measured with weighted kappa tests. Interclass correlation coefficients compared interobserver reliability.
  
  
  RESULTS
  There was no significant difference in perceptibility detection between the Lenovo M92z desktop, iPad 3, and iPad mini. However, on average, all 3 were significantly better than the Lenovo Z580 laptop (P values ≤.015). No significant difference in the mean absolute error was noted for working length measurements among the 4 viewing devices (P = .3509).
  
  
  CONCLUSIONS
  Although all 4 viewing devices seemed comparable with regard to working length evaluation, the laptop computer screen had lower overall ability to perceive contrast differences.
authors: Department of Endodontics, Louisiana State University Health Science Center, School of Dentistry, New Orleans, Louisiana. Electronic address: tlally01@gmail.com.
authors: Trent
authors: T
authors: Lally
authors: Department of Biomedical and Diagnostic Sciences, University of Detroit Mercy, School of Dentistry, Detroit, Michigan.
authors: James R
authors: JR
authors: Geist
authors: Biostatistics Program, Louisiana State University School of Public Health, New Orleans, Louisiana.
authors: Qingzhao
authors: Q
authors: Yu
authors: Department of Endodontics, Louisiana State University Health Science Center, School of Dentistry, New Orleans, Louisiana.
authors: Van T
authors: VT
authors: Himel
authors: Department of Endodontics, Louisiana State University Health Science Center, School of Dentistry, New Orleans, Louisiana.
authors: Kent
authors: K
authors: Sabey
mesh_terms: D003201:Computers; D006801:Humans; D015588:Observer Variation; D009811:Odontometry / Q000295:instrumentation*; D019252:Radiography, Dental, Digital / Q000295:instrumentation*; D014796:Visual Perception
keywords: Contrast; display; perceptibility curve; perception; working length