title: Mechanical, morphologic, and chemical effects of carbamide peroxide bleaching agents on human enamel in situ.
abstract: OBJECTIVE
  To evaluate the morphologic, mechanical, and chemical effects of carbamide peroxide bleaching agents on human enamel in situ.
  
  
  METHODS
  Enamel slabs from extracted human teeth were divided in two and mounted on contralateral sides of removable maxillary appliances fabricated for three participants. Soft vinyl trays were adapted intraorally over the arch; one side contained a bleaching agent, and the other served as a control. Vital bleaching was conducted in vivo three times with three different bleaching agents and with new enamel specimens each time. Tests of Knoop microhardness, scanning electronic microscopy (SEM), and energy dispersive x-ray (EDX) were performed and analyzed by ANOVA.
  
  
  RESULTS
  No statistically significant differences were found between matched test and control specimens concerning microhardness values, morphology, or elemental content.
  
  
  CONCLUSIONS
  Enamel surface showed no mechanical, morphologic, or chemical changes following bleaching in situ with three different carbamide peroxide agents.
authors.affiliation: Center for Graduate Studies in Prosthodontics, Department of Prosthodontics, Faculty of Dental Medicine, The Hebrew University-Hadassah, Jerusalem, Israel.
authors.forename: Ami
authors.initials: A
authors.lastname: Smidt
authors.forename: Osnat
authors.initials: O
authors.lastname: Feuerstein
authors.forename: Merav
authors.initials: M
authors.lastname: Topel
mesh_terms: D000328:Adult; D002118:Calcium / Q000032:analysis; D000077463:Carbamide Peroxide; D002244:Carbon / Q000032:analysis; D003743:Dental Enamel / Q000737:chemistry / Q000187:drug effects* / Q000648:ultrastructure; D005459:Fluorides / Q000032:analysis; D006244:Hardness; D006801:Humans; D008855:Microscopy, Electron, Scanning; D010100:Oxygen / Q000032:analysis; D010545:Peroxides / Q000008:administration & dosage / Q000494:pharmacology*; D010758:Phosphorus / Q000032:analysis; D013052:Spectrometry, X-Ray Emission; D013314:Stress, Mechanical; D058205:Tooth Bleaching Agents / Q000008:administration & dosage / Q000494:pharmacology*; D014508:Urea / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D010545:Peroxides; D058205:Tooth Bleaching Agents; D010758:Phosphorus; D000077463:Carbamide Peroxide; D002244:Carbon; D014508:Urea; D005459:Fluorides; D010100:Oxygen; D002118:Calcium