Characteristics of secondary radiation from fixed dentures under γ-therapy of cancerous new growth of maxillofacial region

Literary data and own clinical investigations evidence that during carrying out of remote γ-therapy of cancerous new growth in head and neck regions it is possible secondary influence of rays on oral cavity tissues: parodont, mucous membrane of oral cavity, lachrymal glands, receptor mechanism. It is connected with high irradiation dose of these tissues as a result of secondary radiation from natural teeth and fixed metal dentures. Taking into consideration the secondary irradiation factor from metal dentures, we carried out experimental investigations at the Department of Radiation Researches of Azerbaijan National Academy of Sciences with the purpose of dose detection are produced by inverse scattering and secondary electron irradiation from modern dental metal materials: gold-alloy, cobalt- chromium alloy, silver-palladium alloy, titanium nitride alloy, metallic-ore ceramics, stainless steel. Standard metallic samples of these materials by area 100 mm2 and thickness 25 mm have been irradiated by GUT-Co-400 device with I Gy dose at F=60 cm. Secondary irradiation intensity has been determined by photometry. Plate from stainless steel is as an standard. The results of carried out investigation shown the strengthening of scattering irradiation from 12 to 38 % with electrons track length from 0.8 to 1.9 mm are dependence from metal atomic weight. Tooth plastic protective kappa with thickness 3 mm for teeth of upper and lower jaws has been proposed with the purpose of prophylaxis of negative secondary irradiation influence to the tissue of oral cavity from metal dentures