title: Changes in translucency and color of particulate filler composite resins.
abstract: OBJECTIVE
  The purpose of this study was to examine changes in translucency and color of particulate filler composite resins that can be fabricated into metal-free crowns.
  
  
  METHODS
  Eight types of materials were used in this study. The particulate filler composite resins were represented by Artglass, BelleGlass, Estenia, Gradia, and Targis. Herculite XRV and Solidex were the conventional composite resins for crowns and fixed partial denture facings, and Empress was the ceramic material. Disks with a thickness of 1.0 mm were fabricated from each material and subjected to an accelerated test by immersion in 60 degrees C distilled water for up to 8 weeks. Color measurements were made before and after water immersion. Changes in translucency were evaluated by determining the contrast ratio, and changes in color were evaluated by determining color difference.
  
  
  RESULTS
  After water immersion, Targis and Solidex demonstrated a significant increase in contrast ratio (6% to 7%) and a decrease in translucency. A color difference of more than 2.0, a visually perceptible value, was found for Targis, Gradia, and Solidex. However, the maximum color difference for these was 3.0, a value that would be considered clinically acceptable.
  
  
  CONCLUSIONS
  Within the limitations of this study, the particulate filler composite resins were stable in both translucency and color.
authors.affiliation: Division of Oromaxillofacial Regeneration, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 5650871, Japan. tnakamur@dent.osaka-u.ac.jp
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
authors.forename: Osamu
authors.initials: O
authors.lastname: Saito
authors.forename: Masakazu
authors.initials: M
authors.lastname: Mizuno
authors.forename: Hideaki
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D003442:Crowns; D003776:Dental Porcelain / Q000737:chemistry; D003793:Dental Restoration, Permanent; D005899:Glass Ionomer Cements / Q000737:chemistry; D008027:Light; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D010316:Particle Size; D011140:Polyurethanes / Q000737:chemistry; D017797:Prosthesis Coloring; D019279:Resin Cements; D012823:Silicate Cement / Q000737:chemistry; D012822:Silicon Dioxide
chemical_list: D000538:Aluminum Silicates; D003188:Composite Resins; D005899:Glass Ionomer Cements; C470230:Gradia; C075815:IPS-Empress ceramic; D008689:Methacrylates; D011140:Polyurethanes; D019279:Resin Cements; C113676:Solidex; C110370:belleGlass; C111282:dental polyglass; C091839:urethanetrimethacrylate; C065770:Herculite XR; D003776:Dental Porcelain; D012823:Silicate Cement; D012822:Silicon Dioxide