Electron paramagnetic resonance dosimetry of dentine following removal of organic material.

The feasibility of using dentine from surgically extracted human teeth as in vivo dosimeters was investigated. The organic fraction of human dentine was removed by Soxhlet extraction with diethylenetriamine. The specimens were then crushed and 75 to 250 microns granules were given doses of gamma radiation ranging from 50 mGy to 8 Gy. Following irradiation, electron paramagnetic resonance spectra were collected. Signals were detected with Lande factors of g = 2.0018, line width = 0.903 mT; and g = 1.9961, line width = 0.444 mT. These signals have both been reported for hydroxyapatite of bone and enamel. Several other signals were also seen but not characterized. It was concluded that doses of 500 mGy or less may be resolved with prior removal of the organic component of dentine.