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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-22 2:28 |
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Conference: Bucharest University Faculty of Physics 2010 Meeting
Section: Polymer Physics
Title:
Retrospective Dose Assessment Using Thermoluminescence of Tooth Enamel
Authors:
Margareta Cherestes (1), M. Secu (2), C. Cherestes (1), M. V. Paraschiva (1), Livia Maria Constantinescu (3), C. Barca (3), I. Simina (4)
Affiliation:
(1)Dozimed Ltd., Dosimetry Laboratory, Bucharest-Magurele, 077125 ROMANIA
(2)National Institute of Materials Physics (NIMP), Bucharest-Magurele, 077125 ROMANIA
(3)University of Bucharest, Faculty of Physics, P.O.BOX.MG-11, Bucharest, Romania
(4)Medinvest Ltd., Dental Office, Brasov, ROMANIA
E-mail
codrut.cherestes@dozimed.ro
Keywords:
tooth enamel, thermoluminescence, retrospective dosimetry
Abstract:
Retrospective assessment of the radiation exposure is an important tool for the assessment of individual doses, used to provide information on exposure to ionizing radiation many years after the radiological event. The human calcified tissues (as bones and teeth) are of special interest to retrospective dosimetry. Tooth enamel is preferred in retrospective dosimetry because this tissue is completely formed in childhood and once formed, is never remodeled. The usefulness of enamel for dosimetry results from its high content of hydroxyapatite. Carbonate impurities, which are incorporated into or attached to the surface of hydroxyapatite crystals during formation, are converted to CO2 radicals through absorption of ionizing radiation. The concentration of radicals increases with the absorbed dose. In the present work we have studied the thermoluminescence (TL) properties of tooth enamel after gamma-rays irradiation at low doses. Tooth enamel sample preparation was done by separating the roots from crown and then the enamel from dentine using mechanical and chemical methods followed by grinding (about 100ìm grains size) and etching. The absorbed doses have been assessed using dose calibration curve (dose response curve). Each sample was irradiated at Cs-137 with 5 doses in 25 mGy – 200 mGy interval. The original absorbed dose in the enamel sample was obtained from the negative intercept of the regression line with the dose axis. The investigation has shown the feasibility to detect absorbed doses bellow 300mGy using the thermoluminescence properties of tooth enamel.
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