title: Microcomputerised tomography evaluation of 10% carbamide peroxide applied to enamel.
abstract: OBJECTIVE
  There is still some controversy in the dental literature whether carbamide peroxide bleaching causes demineralization of teeth. One of the reasons for this controversy is that there is as yet no reliable, non-destructive in vitro method for assessing mineral loss in bleached teeth. The objective of this study was to investigate the possible demineralization effect of 10% carbamide peroxide bleaching agent on enamel and dentine non-destructively.
  
  
  METHODS
  microCT images were obtained of 12 human molar tooth sections. These sections had 10% carbamide peroxide applied for eight hours a day over a period of 15 days. Further tomographic images were obtained and the mineral content prior to and post bleaching assessed.
  
  
  RESULTS
  A total of 144 regions were evaluated using the image processing language available in the work station. The application of 10% carbamide peroxide was found to cause demineralization of the enamel extended to a depth of 50 microm below the enamel surface (Paired t-test, p<0.05).
  
  
  CONCLUSIONS
  This study confirmed that microCT was indeed a highly suitable method for assessing mineral content of dental enamel after bleach application. It is recommended that application of bleaching agents should be carefully considered in patients susceptible to caries and tooth wear.
authors: Department of Restorative Dentistry, Leeds Dental Institute, University of Leeds, Worsley Building Level 6, Clarendon Way, Leeds LS2 9LU, UK. n.efeoglu@leeds.ac.uk
authors: Neslihan
authors: N
authors: Efeoglu
authors: David
authors: D
authors: Wood
authors: Candan
authors: C
authors: Efeoglu
mesh_terms: D000077463:Carbamide Peroxide; D003743:Dental Enamel / Q000187:drug effects*; D003804:Dentin / Q000187:drug effects; D004338:Drug Combinations; D006801:Humans; D008963:Molar / Q000187:drug effects; D016877:Oxidants / Q000633:toxicity*; D010545:Peroxides / Q000633:toxicity*; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014073:Tooth Bleaching / Q000009:adverse effects*; D017001:Tooth Demineralization / Q000139:chemically induced*; D014508:Urea / Q000031:analogs & derivatives* / Q000633:toxicity
chemical_list: D004338:Drug Combinations; D016877:Oxidants; D010545:Peroxides; D000077463:Carbamide Peroxide; D014508:Urea