Effect of Tooth Position in the Oral Cavity for Various Irradiation Geometries in Dental ESR Dosimetry

Experiment on the effect of tooth position in oral cavity for various irradiation geometries was performed by using a human head phantom containing 32 permanent teeth. The head phantom was connected with the upper part of Rando phantom and irradiated by 60Co gamma-rays with anteroposterior (AP), posteroanterior (PA) and right lateral (RLAT) geometries. Exposure for AP geometry was about 1290×10-4C/kg (500 R) at the labial side of upper central incisors, while for PA and RLAT geometries the phantom was turned by 180 and 90 degrees, respectively, and irradiated for the same period of time as for AP geometry. Although an established trend on the whole was found, correlation between dose of tooth enamel and its location in the oral cavity was not strong at least for high energy gamma-rays from 60Co (average 1.25 MeV) .