The 3rd international intercomparison on EPR tooth dosimetry: Part 1, general analysis

The, objective of the 3rd International Intercomparison on Electron Paramagnetic Resonance (EPR) Tooth Dosimetry was the evaluation of laboratories performing tooth enamel dosimetry below 300 mGy. Participants had to reconstruct the absorbed dose in tooth enamel from 1 1 molars, which were cut into two halves. One half of each tooth was irradiated in a Co-60 beam to doses in the ranges of 30-100 mGy (5 samples), 100-300mGy (5 samples), and 300-900 mGy (1 sample). Fourteen international laboratories participated in this intercomparison programme. A first analysis of the results and an overview of the essential features of methods applied in different laboratories are presented. The relative standard deviation of results of all methods was better than 27% for applied doses in the range of 79-704 mGy. In the analysis of the unirradiated tooth halves 8% of the samples were identified as outliers with additional absorbed dose above background dose. (C) 2004 Elsevier Ltd. All rights reserved