title: Effects of staining and bleaching on a nanohybrid composite with or without surface sealant.
abstract: OBJECTIVE
  The effect of different staining solutions and a bleaching procedure on color stability and surface roughness of a nanohybrid resin composite were evaluated with or without liquid resin polishing (RP).
  
  
  METHODS
  Ninety-six disc-shaped resin composite specimens (A1 Shade, Z550 Filtek 3M ESPE, St. Paul, MN, USA) were prepared and divided randomly into two groups (n = 48). Liquid RP (BisCover LV, Bisco Inc., Schaumburg, IL, USA) was applied in one group (RP) and not in the other (P). Specimen color and surface roughness were determined using a colorimeter and profilometer, respectively. After baseline measurements, each group was divided into four subgroups (n = 12) for immersion in a control (distilled water) or three different staining solutions (ice tea, red wine, and cola) for 1 week. Color and surface roughness were then reevaluated. After measurements, all specimens were bleached using a 35% hydrogen peroxide gel. The color and surface roughness of the specimens were reevaluated.
  
  
  METHODS
  Data were subjected to an analysis of variance for repeated measurements among the groups (P < 0.05).
  
  
  RESULTS
  Staining and bleaching did not change the surface roughness of the RP and P groups (P > 0.05). Discoloration in the red wine group was higher than for the other staining solutions for the RP (P < 0.001) and P groups (P = 0.018).
  
  
  CONCLUSIONS
  Application of liquid RP did not enhance the color stability and surface roughness of the composite resin restoration.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Baskent University, Ankara, Turkiye.
authors.forename: Derya Merve
authors.initials: DM
authors.lastname: Halacoglu
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Baskent University, Ankara, Turkiye.
authors.forename: Kıvanc
authors.initials: K
authors.lastname: Yamanel
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Baskent University, Ankara, Turkiye.
authors.forename: Saffet
authors.initials: S
authors.lastname: Basaran
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Baskent University, Ankara, Turkiye.
authors.forename: Duygu
authors.initials: D
authors.lastname: Tuncer
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, Baskent University, Ankara, Turkiye.
authors.forename: Cigdem
authors.initials: C
authors.lastname: Celik
keywords: Bleaching; nanohybrid composite; staining; surface roughness; surface sealant