title: Impact of Crest Night Effects bleaching gel on dental enamel, dentin and key restorative materials. In vitro studies.
abstract: OBJECTIVE
  To examine the effects of a paint-on 19% sodium percarbonate 'overnight' bleaching gel on the structure and integrity of enamel, dentin and some common restorative materials, with a laboratory cycling model.
  
  
  METHODS
  Enamel, root dentin and restorative materials (glass-ionomer, composite and amalgam) were prepared in methacrylate molds with surface polishing. A treatment regimen was carried out including diurnal incubation in pooled human saliva and including twice daily toothbrushing with standard fluoridated dentifrice. Test samples were treated daily with Crest Night Effects bleaching gel, which included drying of surfaces, painting of percarbonate bleaching gel, and then incubation throughout the day (8 hours) to simulate overnight wear. Treatments were carried out over 14 days, to simulate clinical exposure periods. Control and test specimens were evaluated for surface and subsurface structure and morphological integrity utilizing surface microhardness, surface profilometry, and confocal laser scanning microscopy.
  
  
  RESULTS
  Percarbonate bleaching film treatments had no effects on enamel or root dentin surface microhardness, or on subsurface ultrastructural integrity of enamel and coronal dentin. Surface profilometry confirmed retention of small amounts of residual silicone polymers, which contributed to CLSM air objective appearance and surface roughness measures. Restoratives were generally passive to bleaching gel treatments, though composite showed a tendency to attract retained residual silicone film.
authors.affiliation: The Health Care Research Center, The Procter & Gamble Company, Mason, OH 45040-8006, USA. White.DJ.1@pg.com
authors.forename: Donald J
authors.initials: DJ
authors.lastname: White
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Kozak
authors.forename: James R
authors.initials: JR
authors.lastname: Zoladz
authors.forename: Heinz J
authors.initials: HJ
authors.lastname: Duschner
authors.forename: Hermann
authors.initials: H
authors.lastname: Goetz
mesh_terms: D001641:Bicuspid; D002254:Carbonates / Q000008:administration & dosage*; D003188:Composite Resins / Q000737:chemistry; D003481:Cuspid; D003723:Dental Amalgam / Q000737:chemistry; D003743:Dental Enamel / Q000737:chemistry* / Q000187:drug effects; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent; D003804:Dentin / Q000737:chemistry* / Q000187:drug effects; D003806:Dentin Permeability / Q000187:drug effects; D005899:Glass Ionomer Cements / Q000737:chemistry; D006244:Hardness / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D018613:Microscopy, Confocal; D008963:Molar; D012463:Saliva / Q000737:chemistry / Q000187:drug effects; D013499:Surface Properties; D014073:Tooth Bleaching / Q000379:methods*
chemical_list: D002254:Carbonates; D003188:Composite Resins; C479358:Crest Night Effects; D003764:Dental Materials; D005899:Glass Ionomer Cements; D003723:Dental Amalgam; C034738:sodium percarbonate