title: Dose reduction of two digital sensor systems measuring file lengths.
abstract: OBJECTIVE
  The aim of this study was to determine the effect of dose reduction on the image quality of two sensor systems with automatic greyscale adjustment.
  
  
  METHODS
  Two digital sensor systems, Sidexis (Siemens, Bensheim, Germany) and Digora (Soredex, Helsinki, Finland), were tested. The image quality of the systems was determined by comparing lengths of endodontic files (025, 020, 015, and 010 files) and a premolar root in the digital images with lengths on conventional radiographic films. For the experiments the exposure was changed to 100%, 50%, 25%, 12.5%, 6.25%, and 3.125% of that for Ektaspeed films.
  
  
  RESULTS
  The lengths of 025 and 020 files and the premolar root in the digital images were comparable with the lengths on films even if the exposure was reduced to 6% of that used for Ektaspeed films. The lengths of 015 files reduced as the exposure was reduced. The lengths of 010 files were significantly shorter than the lengths on films.
  
  
  CONCLUSIONS
  With the systems tested, a dose reduction of approximately 95% compared with Ektaspeed films is possible to determine the lengths of a premolar root and 025 and 020 files. For thinner objects a dose reduction is questionable.
authors: Department of Oral Radiology, Academic Centre for Dentistry, Amsterdam, The Netherlands.
authors: X L
authors: XL
authors: Velders
authors: G C
authors: GC
authors: Sanderink
authors: P F
authors: PF
authors: van der Stelt
mesh_terms: D000704:Analysis of Variance; D001641:Bicuspid; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging; D009811:Odontometry; D011829:Radiation Dosage; D011856:Radiographic Image Enhancement / Q000379:methods*; D011861:Radiography, Dental / Q000295:instrumentation* / Q000379:methods; D012016:Reference Values; D018915:Root Canal Preparation / Q000295:instrumentation*; D014092:Tooth Root / Q000000981:diagnostic imaging*; D014962:X-Ray Film