title: Effects of hydrogen peroxide bleaching strip gels on dental restorative materials in vitro: surface microhardness and surface morphology.
abstract: OBJECTIVE
  This study examined the effects of peroxide tooth bleaching, including Crest Whitestrips hydrogen peroxide gel treatments, on the surface hardness and morphology of common dental restorative treatments.
  
  
  METHODS
  American Dental Association (ADA) recommended dental restorative materials, including amalgam, dental gold, porcelain, glass ionomer, and composites, were prepared according to manufacturers' instructions. A cycling treatment methodology was employed which alternated ex vivo human salivary exposures with bleaching treatments under conditions of controlled temperature and durations of treatment. Bleaching treatments included commercial Crest Whitestrips bleaching gels, which utilize hydrogen peroxide as the in situ bleaching source, and several commercial carbamide peroxide bleaching gels. Control treatments included placebo gels and an untreated group. Crest Whitestrips bleaching included treatment exposures simulating recommended clinical exposures (14 hours), along with excess bleaching simulating exposure to five times suggested Crest Whitestrips use. At the conclusion of treatments, surface microhardness measures and surface morphological assessments with standard and variable pressure (VP-) SEMs were conducted to assess the effects of bleaching exposure on the surface morphology and structural integrity of the restoratives.
  
  
  RESULTS
  Surface microhardness and SEM measures revealed no significant deleterious effects on the restoration surfaces from Whitestrips gels.
  
  
  CONCLUSIONS
  These results confirm that tooth bleaching from the selected commercial hydrogen peroxide or carbamide peroxide bleaching systems does not produce changes in surface morphology or microhardness of common dental restorative materials. These results support the clinical safety of the selected commercial bleaching systems to the oral environment, matching results obtained from long-term use of these ingredients applied in dental offices and available in commercial formulations.
authors.affiliation: Applied Structure and Microanalysis Medical Faculty, Johannes Gutenberg University, Mainz, Germany.
authors.forename: Heinz
authors.initials: H
authors.lastname: Duschner
authors.forename: Hermann
authors.initials: H
authors.lastname: Götz
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
mesh_terms: D000077463:Carbamide Peroxide; D003188:Composite Resins / Q000737:chemistry; D003723:Dental Amalgam / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry; D003793:Dental Restoration, Permanent; D004338:Drug Combinations; D005782:Gels; D005899:Glass Ionomer Cements / Q000737:chemistry; D006047:Gold Alloys / Q000737:chemistry; D006244:Hardness; D006801:Humans; D006861:Hydrogen Peroxide / Q000737:chemistry*; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016877:Oxidants / Q000737:chemistry*; D010545:Peroxides / Q000737:chemistry; D012463:Saliva / Q000737:chemistry; D013499:Surface Properties; D014073:Tooth Bleaching; D014508:Urea / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D003188:Composite Resins; D003764:Dental Materials; D004338:Drug Combinations; D005782:Gels; D005899:Glass Ionomer Cements; D006047:Gold Alloys; D016877:Oxidants; D010545:Peroxides; D003776:Dental Porcelain; D000077463:Carbamide Peroxide; D003723:Dental Amalgam; D014508:Urea; D006861:Hydrogen Peroxide