title: An in vitro radiographic analysis of the density of dental luting cements as measured by CCD-based digital radiography.
abstract: OBJECTIVE
  According to the ISO, the radiopacity of luting cements should be equal to or greater than that of aluminum. The aim of this in vitro study was to determine the radiopacity of 13 commercially available dental luting cements and compare them with human enamel and dentin.
  
  
  METHODS
  Five classes of luting cements were evaluated: zinc phosphate (Cegal N and Harvard Zinc Phosphate), zinc polycarboxylate (Harvard Polycarboxylate and Hoffmann's Carboxylate), glass ionomers (Ketac Cem Easymix, Ketac Cem Radiopaque, and Fuji I), resin-modified glass ionomer (Rely X Luting), and resin cements (Multilink Automix, Variolink II, Speed CEM, Rely X Unicem Automix, and three shades of Variolink Veneer). Tooth slices served as controls. Five specimens of each material measuring 8 mm in diameter and 1 mm thick were prepared and radiographed alongside tooth slices and an aluminum stepwedge using a Trophy RVG sensor. The radiopacity values were expressed in mm Al and analyzed by the ANOVA and Tukey tests (P < .05).
  
  
  RESULTS
  All the cements examined except Variolink Veneer had significantly higher radiopacities than that of dentin. Rely X Unicem Automix, glass ionomer, and resin-modified glass-ionomer cements demonstrated radiopacities that were not significantly different with respect to enamel. Zinc phosphate, zinc polycarboxylate, and three of the resin cements presented radiopacity values that were significantly greater than that of enamel.
  
  
  CONCLUSIONS
  Almost all the investigated materials presented an acceptable radiopacity. Radiopacity of dental cements seems to depend more on the presence of elements with high atomic numbers than on the type of the material.
authors.affiliation: Department of Prosthodontics, University of Belgrade, Belgrade, Serbia. djordje_ayu@yahoo.com
authors.forename: Djordje
authors.initials: D
authors.lastname: Antonijevic
authors.forename: Danimir
authors.initials: D
authors.lastname: Jevremovic
authors.forename: Svetlana
authors.initials: S
authors.lastname: Jovanovic
authors.forename: Kosovka
authors.initials: K
authors.lastname: Obradovic-Djuricic
mesh_terms: D000535:Aluminum / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003287:Contrast Media / Q000737:chemistry; D003738:Dental Cements / Q000737:chemistry*; D003743:Dental Enamel / Q000000981:diagnostic imaging; D003804:Dentin / Q000000981:diagnostic imaging; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008277:Magnesium Oxide / Q000737:chemistry; D008422:Materials Testing; D011076:Polycarboxylate Cement / Q000737:chemistry; D019252:Radiography, Dental, Digital; D019279:Resin Cements / Q000737:chemistry; D015034:Zinc Oxide / Q000737:chemistry; D015036:Zinc Phosphate Cement / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003287:Contrast Media; D003738:Dental Cements; D005899:Glass Ionomer Cements; C515713:Ketac Molar Easymix; D011076:Polycarboxylate Cement; C483701:Rely X Unicem; D019279:Resin Cements; C084550:Vitremer; C502351:multilink adhesive system; C084541:Fuji glass-ionomer lining cement; C103502:Variolink; D008277:Magnesium Oxide; D015036:Zinc Phosphate Cement; C074226:Harvard Cement; C040235:Ketac-cem; D000535:Aluminum; D015034:Zinc Oxide