Computation of exposure build-up factors in teeth

The G-P fitting method has been used to compute the exposure build-up factor of teeth [enamel outer surface (EOS), enamel middle (EM), enamel dentin junction towards enamel (EDJE), enamel dentin junction towards dentin (EDJD), dentin middle (DM) and dentin inner surface (DIS)] for a wide energy range (0.015-15 MeV) up to the penetration depth of 40 mean free paths. The dependence of exposure build-up factor on incident photon energy, penetration depth, electron density and effective atomic number has also been studied. The computed exposure build-up factor is useful to estimate the relative dose distribution in different regions of teeth.