Method of determining radiation dosage by monitoring dental gold restorations

Abstract

An experiment was conducted to determine whether there was a direct correlation of total neutron dose to the neutron activation of dental Au alloy restorations. To test the hypothesis, Au inlays (equal in volume to the cubes used in the reactor experiment) were placed in the second deciduous molars of 10 young monkeys, which were subsequently exposed to radiation at various distances to nuclear explosions. The measured activities of the Au samples were corrected by standard methods for resolving time, geometry, counting efficiency, and decay time. The resulting activities for each sample at the time of exposure were then adjusted for the amount of Au per sample and the activity expressed as disintegrations/min/g Au. The activities of all the samples in each group were combined to obtain the mean activity/g Au at each position. The mean induced activity of the Au for each group of animals was proportional to the neutron dose in rads as measured by the Hurst fission foil technic. The mean neutron dose varied from 374 to 485 rad, resulting in induced activities of the Au varying from 1.16 to 1.94 x 10/sup 7/ disintegrations/ min/g. Histopathologically, no significant differences from the normal were found. It wasmore » concluded that the activity of the Au restorations can be used to calculate the extent of neutron flux after a nuclear accident. This can be accomplished immediately after exposure, wliereas other tissue changes and resulting clinical symptomatology do not become apparent for some time. (TCO)« less