title: Comparison of conventional and digital radiography systems with regard to radiopacity of root canal filling materials.
abstract: OBJECTIVE
  To compare the radiopacity of five root filling materials as measured on digitized E-speed films, storage phosphor plate and CCD sensor images.
  
  
  METHODS
  Radiopacity of Resilon cones and Epiphany, MM-Seal, EndoREZ and AH Plus sealers were investigated. Ten acrylic plates were prepared and filled with the materials. Samples were radiographed together with samples of dentine and an aluminium stepwedge. Images were obtained using E-speed films, Digora storage phosphor plates and Schick CDR CCD sensor. Conventional radiographs were digitized using a desktop scanner. Mean grey values of the materials, stepwedge and dentine were measured using the histogram analysis function of Photoshop 7.0. A graph of radiographic density versus thickness of the aluminium was drawn for each image from which the radiographic densities of the materials were determined in relation to the aluminium thickness. The mean was calculated, and the data were analysed using repeated measures anova and Bonferroni tests (P<0.05).
  
  
  RESULTS
  There were significant differences between different imaging modalities (P=0.018) and root filling materials (P<0.001). A statistically significant interaction between imaging modality and material was also observed (P<0.001). All materials had radiopacity above 3mm of aluminium regardless of the imaging technique. The radiopacity of Resilon and Epiphany was significantly higher on digital images compared with digitized E-speed film images (P<0.001).
  
  
  CONCLUSIONS
  The choice of imaging system may effect radiopacity measurements. It is possible that radiopacity as recorded on traditional or digitized films is not indicative of the radiopacity as recorded on a digital sensor.
authors.affiliation: Department of Endodontics, School of Dentistry Ege University, Bornova, Izmir, Turkey.
authors.forename: I
authors.initials: I
authors.lastname: Akcay
authors.forename: B
authors.initials: B
authors.lastname: Ilhan
authors.forename: N
authors.initials: N
authors.lastname: Dundar
mesh_terms: D000535:Aluminum / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003287:Contrast Media / Q000737:chemistry; D003720:Densitometry; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging*; D003804:Dentin / Q000000981:diagnostic imaging; D004853:Epoxy Resins / Q000737:chemistry; D006801:Humans; D008422:Materials Testing; D019252:Radiography, Dental, Digital / Q000295:instrumentation / Q000379:methods*; D012387:Root Canal Filling Materials / Q000737:chemistry*; D014962:X-Ray Film; D014963:X-Ray Intensifying Screens
chemical_list: D003188:Composite Resins; D003287:Contrast Media; C481259:EndoRez; D004853:Epoxy Resins; D012387:Root Canal Filling Materials; C486893:epiphany sealer; C534916:epoxy resin-based root canal sealer; C486892:resilon sealer; D000535:Aluminum