EPR-dosimetry with carious teeth

The effect of caries in EPR dosimetry of tooth enamel (in the dose range of 0-1 Gy) was investigated. The enamel of each tooth was divided into cariou s, non-carious and intermediate portions. The EPR signals of enamel at g = 2.0018 (dosimetric) and g = 2.0045 (native) were examined. The intensity of the dosimetric signal was the same for all three portions, while that of t he native signal was higher for carious portions than for non-carious and i ntermediate portions. Reconstruction of the laboratory applied doses was do ne using all portions. Reasonable correlation between nominal and reconstru cted doses was found in most cases. The effect of alkali treatment on the n ative and dosimetric signals of enamel was also tested. Reduction of the na tive signal intensity, particularly in the carious portions, was found to b e the only significant effect. This resulted in a slight improvement in the accuracy of the reconstructed doses. (C) 2000 Elsevier Science Ltd. All ri ghts reserved.