title: Alterations in human enamel surface morphology following the use of an office bleaching agent and consecutive application of 37% phosphoric acid in vivo.
abstract: OBJECTIVE
  The aim of this in vivo study was to evaluate the effects of a visible light-activated in-office bleaching agent, Opalescence Xtra (35% hydrogen peroxide) on the external enamel surface of human teeth by using scanning electron microscopy (SEM).
  
  
  METHODS
  The labial surfaces of nine upper incisors from nine different patients were divided into four parts, and a bleaching agent was applied to the mesial halves of the teeth. Three weeks following this treatment, the teeth were extracted and divided into four quadrants. Each quadrant was treated with a different procedure and the samples were examined under SEM. The SEM photographs were blindly evaluated by a jury of four experts.
  
  
  RESULTS
  Although there were no statistical differences in the rating of surface morphology of bleached and control groups, the 37% phosphoric acid etched and acid etched + bleached enamel samples demonstrated a statistically significant dissimilar surface morphology (p < 0.05).
  
  
  CONCLUSIONS
  The bleached + etched enamel treatment showed an uneven etched surface compared to the acid etched control.
authors.affiliation: Department of Prosthodontics, Faculty of Dentistry, University of Ankara, Turkey.
authors.forename: B
authors.initials: B
authors.lastname: Yurdukoru
authors.forename: A C
authors.initials: AC
authors.lastname: Akören
authors.forename: M K
authors.initials: MK
authors.lastname: Unsal
mesh_terms: D000134:Acid Etching, Dental; D000328:Adult; D000077463:Carbamide Peroxide; D003743:Dental Enamel / Q000187:drug effects* / Q000648:ultrastructure; D004338:Drug Combinations; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000627:therapeutic use; D008027:Light; D008297:Male; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D016877:Oxidants / Q000008:administration & dosage / Q000627:therapeutic use*; D010545:Peroxides / Q000008:administration & dosage / Q000627:therapeutic use; D010756:Phosphoric Acids / Q000008:administration & dosage / Q000627:therapeutic use*; D016037:Single-Blind Method; D014073:Tooth Bleaching / Q000379:methods; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use
chemical_list: D004338:Drug Combinations; D016877:Oxidants; D010545:Peroxides; D010756:Phosphoric Acids; D000077463:Carbamide Peroxide; D014508:Urea; D006861:Hydrogen Peroxide