title: In vitro FT-IR study of the effects of hydrogen peroxide on superficial tooth enamel.
abstract: OBJECTIVE
  The aim of the present study was to determine the alteration in human enamel after hydrogen peroxide treatment using FT-IR spectroscopy. It is hypothesized that infrared spectroscopy is capable of showing alterations in human enamel after peroxide treatment and the alteration in enamel is proportional to peroxide concentration.
  
  
  METHODS
  The effects of 10, 20 and 30% hydrogen peroxide solutions on human enamel were tested. Thirty non-carious human teeth, extracted for periodontal reasons, were used in this study. They were divided into 3 groups of 10, according to the peroxide concentration, sectioned, and the specimens were embedded in resin for infrared spectroscopic analysis. The total treatment time was 120 min. Spectra of the specimens were taken before treatment and 30, 60 and 120 min after it. Another spectrum was taken in a week.
  
  
  RESULTS
  Infrared spectroscopic analysis showed two distinct bands (biological PO(4)nu1 and nu2) that were capable of describing the alterations in enamel structure. On comparing the infrared spectra of non-treated and treated specimens, structural changes were detected in the superficial enamel. The alteration in enamel was proportional to treatment time and hydrogen peroxide concentration. Higher concentration and longer treatment time resulted in more severe alterations. The numerical analysis of the spectra revealed that on using concentrated hydrogen peroxide solutions the alterations of the IR spectra were more pronounced. The spectra taken in 1 week after treatment did not show spontaneous reversibility in enamel structure.
  
  
  CONCLUSIONS
  At-home and in-office peroxide-containing bleaching agents are capable of causing alteration in enamel at low and high concentrations as well. According to the results of this study it is recommended to perform tooth whitening using low concentration of hydrogen and/or carbamide peroxide, and shorten treatment time to reduce the possible destruction but reach the required change in color.
authors.affiliation: University of Debrecen, Medical and Health Science Center, Faculty of Dentistry, Department of Prosthetic Dentistry, P.O. Box 13, H-4012 Debrecen, Hungary. bistey@jaguar.dote.hu
authors.forename: Tamas
authors.initials: T
authors.lastname: Bistey
authors.forename: István P
authors.initials: IP
authors.lastname: Nagy
authors.forename: Anett
authors.initials: A
authors.lastname: Simó
authors.forename: Csaba
authors.initials: C
authors.lastname: Hegedus
mesh_terms: D003743:Dental Enamel / Q000187:drug effects*; D003745:Dental Enamel Permeability; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006861:Hydrogen Peroxide / Q000008:administration & dosage / Q000009:adverse effects*; D006882:Hydroxyapatites / Q000737:chemistry; D016877:Oxidants / Q000008:administration & dosage / Q000009:adverse effects*; D013055:Spectrophotometry, Infrared; D013499:Surface Properties / Q000187:drug effects
chemical_list: D006882:Hydroxyapatites; D016877:Oxidants; D006861:Hydrogen Peroxide