title: Gamma dose response of synthetic A-type carbonated apatite in comparison with the response of tooth enamel.
abstract: Synthetic A-type carbonated apatite samples were irradiated at room temperature with 60Co gamma rays. Their ESR spectra consist of the lines of CO2- and CO3- radicals of orthorhombic and axial symmetry. The measurements carried out immediately after sample irradiation showed that CO2- species are produced by decomposition of CO3- radicals. Intensity of the CO2- lines in the synthetic and enamel samples increases during the first 400 and 200 h after irradiation, respectively. The dependence of the EPR signal on the dose varies with carbonate content of the sample. The dose response curve for tooth enamel is steeper for the synthetic material.
authors.affiliation: Programa de Engenharia Nuclear, COPPE/Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: L M
authors.initials: LM
authors.lastname: Oliveira
authors.forename: A M
authors.initials: AM
authors.lastname: Rossi
authors.forename: R T
authors.initials: RT
authors.lastname: Lopes
mesh_terms: D001031:Apatites / Q000138:chemical synthesis / Q000737:chemistry / Q000528:radiation effects*; D003743:Dental Enamel / Q000737:chemistry / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D005609:Free Radicals; D005720:Gamma Rays; D006801:Humans; D066298:In Vitro Techniques; D011874:Radiometry / Q000379:methods*
chemical_list: D001031:Apatites; D005609:Free Radicals