title: Color stainability of CAD/CAM and nanocomposite resin materials.
abstract: BACKGROUND
  The color stainability of recently introduced computer-assisted design/computer-assisted manufacturing (CAD/CAM) hybrid ceramic and resin nanoceramic is unknown.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to compare the effect of coffee staining on the color of 3 different CAD/CAM restorative materials and a nanocomposite resin.
  
  
  METHODS
  Specimens from a hybrid dental ceramic (VITA Enamic), a resin nanoceramic (Lava Ultimate), a lithium disilicate glass ceramic (IPS e.max CAD), and a nanocomposite resin (Filtek Supreme Ultra Universal) were evaluated for color change due to thermocycling in coffee (n=5). Specimens 0.5 to 0.7 mm and 1 to 1.2 mm in thickness were thermocycled for 5000 cycles. CIEDE2000 color differences (ΔE00) due to thermocycling in coffee were calculated using the color coordinates obtained from a spectroradiometer. ANCOVA was used to analyze the color differences among the materials with thickness as the covariate. Significant differences at average thickness were analyzed with the Tukey-Kramer test.
  
  
  RESULTS
  For color difference due to staining, thickness was a significant covariate (P<.001). Regarding the analysis of color differences, every pair of the tested materials was significantly different (P<.001). Least squares means of color differences (ΔE00) at mean thickness were 4.34 for the nanohybrid composite resin, 3.66 for the resin nanoceramic, 1.35 for the hybrid ceramic, and 0.43 for the lithium disilicate ceramic.
  
  
  CONCLUSIONS
  When exposed to hot and cold coffee, the color change was beyond clinical acceptability for the tested resin nanoceramic and nanocomposite resin materials. The average color change of the hybrid ceramic was clinically perceivable over the tested thickness values. The color change of lithium disilicate ceramic was not clinically perceivable at any tested thickness.
authors.affiliation: Assistant Professor, Baskent University Faculty of Dentistry, Department of Prosthodontics, Ankara, Turkey.
authors.forename: Ozlem
authors.initials: O
authors.lastname: Acar
authors.affiliation: Associate Professor, Division of Restorative Sciences and Prosthodontics, The Ohio State University College of Dentistry, Columbus, Ohio. Electronic address: yilmaz.16@osu.edu.
authors.forename: Burak
authors.initials: B
authors.lastname: Yilmaz
authors.affiliation: Associate Professor, Karadeniz Technical University College of Dentistry, Department of Prosthodontics, Trabzon, Turkey.
authors.forename: Subutay Han
authors.initials: SH
authors.lastname: Altintas
authors.affiliation: Visiting Scholar, Division of Restorative Sciences and Prosthodontics, The Ohio State University College of Dentistry, Columbus, Ohio.
authors.forename: Indumathi
authors.initials: I
authors.lastname: Chandrasekaran
authors.affiliation: Professor Emeritus, Division of Restorative Sciences and Prosthodontics, The Ohio State University College of Dentistry, Columbus, Ohio.
authors.forename: William M
authors.initials: WM
authors.lastname: Johnston
mesh_terms: D003116:Color; D003188:Composite Resins; D017076:Computer-Aided Design; D008422:Materials Testing; D053761:Nanocomposites
chemical_list: D003188:Composite Resins