title: An EPR study of intact and powdered human tooth enamel dried at 400 degrees C.
abstract: An EPR study of human tooth enamel dried at 400 degrees C is presented. Enamel blocks as well as powdered samples were investigated. The discussion deals mainly with three different spectral components, i.e., a CO3(3-) and two different CO2- signals. Using the anisotropic enamel block spectra, a convincing differentiation between the latter two radicals was possible. The first CO2- signal shows no dependence on the orientation of the enamel blocks, disappears from the spectrum upon heating, and was assigned to a surface radical. The second CO2- component is mainly responsible for the angular variation of the enamel blocks and is assigned to a bulk position. For the CO3(3-) ion, the (pseudo) angular variation of its isolated spectrum is presented and discussed. By means of the results presented in this study, earlier interpretation problems are considerably reduced.
authors.affiliation: Laboratory for Crystallography and Study of the Solid State, University Gent, Belgium.
authors.forename: F
authors.initials: F
authors.lastname: Callens
authors.forename: P
authors.initials: P
authors.lastname: Moens
authors.forename: R
authors.initials: R
authors.lastname: Verbeeck
mesh_terms: D001031:Apatites / Q000032:analysis; D002254:Carbonates / Q000032:analysis; D003743:Dental Enamel / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D006358:Hot Temperature; D006801:Humans
chemical_list: D001031:Apatites; D002254:Carbonates