title: Effect of staining solutions on discoloration of resin nanocomposites.
abstract: OBJECTIVE
  To examine the effect of staining solutions on the discoloration of resin nanocomposites.
  
  
  METHODS
  Three resin nanocomposites (Ceram X, Grandio, and Filtek Z350) were light cured for 40 seconds at a light intensity of 1000 mW/cm2. The color of the specimens was measured in %R (reflectance) mode before and after immersing the specimens in four different test solutions [distilled water (DW), coffee (CF), 50% ethanol (50ET) and brewed green tea (GT)] for 7 hours/day over a 3-week period. The color difference (deltaE*) was obtained based on the CIEL*a*b* color coordinate values.
  
  
  RESULTS
  The specimens immersed in DW, 50ET and GT showed a slight increase in L* value. However, the samples immersed in CF showed a decrease in the L* value and an increase in the b* value. CF induced a significant color change (deltaE*: 3.1-5.6) in most specimens but the other solutions induced only a slight color change. Overall, coffee caused unacceptable color changes to the resin nanocomposites.
authors.affiliation: Department of Conservative Dentistry, School of Dentistry and Medical Research Institute, Pusan National University, Yangsan, Korea.
authors.forename: Jeong-Kil
authors.initials: JK
authors.lastname: Park
authors.forename: Tae-Hyong
authors.initials: TH
authors.lastname: Kim
authors.forename: Ching-Chang
authors.initials: CC
authors.lastname: Ko
authors.forename: Franklin
authors.initials: F
authors.lastname: García-Godoy
authors.forename: Hyung-Il
authors.initials: HI
authors.lastname: Kim
authors.forename: Yong Hoon
authors.initials: YH
authors.lastname: Kwon
mesh_terms: D000704:Analysis of Variance; D003069:Coffee; D003116:Color; D003124:Colorimetry; D003188:Composite Resins / Q000737:chemistry; D000431:Ethanol; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D053761:Nanocomposites / Q000737:chemistry; D013053:Spectrophotometry; D013662:Tea; D014867:Water
chemical_list: C520091:CeramX; D003069:Coffee; D003188:Composite Resins; C509998:Grandio; D013662:Tea; C533204:filtek Z350; D014867:Water; D000431:Ethanol