The 4th international comparison on EPR dosimetry with tooth enamel

Abstract

This paper presents the results of the 4th International Comparison of in vitro electron paramagnetic resonance dosimetry with tooth enamel, where the performance parameters of tooth enamel dosimetry methods were compared among sixteen laboratories from all over the world. The participating laboratories were asked to determine a calibration curve with a set of tooth enamel powder samples provided by the organizers. Nine molar teeth extracted following medical indication from German donors and collected between 1997 and 2007 were prepared and irradiated at the Helmholtz Zentrum München. Five out of six samples were irradiated at 0.1, 0.2, 0.5, 1.0 and 1.5 Gy air kerma; and one unirradiated sample was kept as control. The doses delivered to the individual samples were unknown to the participants, who were asked to measure each sample nine times, and to report the EPR signal response, the mass of aliquots measured, and the parameters of EPR signal acquisition and signal evaluation. Critical dose and detection limit were calculated by the organizers on the basis of the calibration-curve parameters obtained at every laboratory. For calibration curves obtained by measuring every calibration sample three times, the mean value of the detection limit was 205 mGy, ranging from 56 to 649 mGy. The participants were also invited to provide the signal response and the nominal dose of their current dose calibration curve (wherever available), the critical dose and detection limit of which were also calculated by the organizers..

Evaluation of external and internal irradiation on uranium mining enterprise staff by tooth enamel EPR spectroscopy

“…This method uses enamel samples prepared from teeth extracted according to medical indications. The error of determination of absorbed dose by this method is about 30-50 mGy [8][9][10][11][12].…”

Dosimetry study of East Kazakhstan residents by tooth enamel EPR spectroscopy

“…All samples were treated by hard alloy dental drills and diamond saws by separating the enamel from the dentine after the cutting of each tooth sample to buccal and lingual parts [15,17]. Dentins were removed carefully in order to prevent the sample from heating which can induce an additional EPR signal and significantly change shape of the signal [18][19][20].…”

“…EPR dosimetry is one of the useful tools for such dose reconstruction [14,15]. This method can determine the radiation doses retrospectively even more than 40 years after the exposure event.…”

ESR dosimeter material properties of phenols compound exposed to radiotherapeutic electron beams

“…This analysis was performed for all beams. Using the 2 the values of the MDD obtained are calculated and reported in Table 1Furthermore, the values of the critical level of dose D CL and the detection limit of dose D DL were calculated following the procedure described for samples of tooth enamel [71] (see Table 1). The values of the detection limit of dose D DL are comparable with those calculated with the other procedure above described and therefore the estimations of these detection limits are reliable.…”