RESUMO
BACKGROUND: The use of panoramic radiography (PR) is a complementary examination to aid in the diagnosis of cases in paediatric dentistry. The lack of specific protocols for these devices, however, can result in high doses of radiation, affecting critical organs such as the thyroid. AIM: To evaluate the discrepancies in ionizing radiation received by the thyroid during PR examinations using anthropomorphic paediatric simulators built from computed tomography images. DESIGN: Two anthropomorphic paediatric phantoms were printed and used, representing children aged 6 and 11 years, with an opening in the thyroid region for the insertion of dosimetric radiographic films. The simulators were subjected to different pre-existing protocols in the PR devices. The radiographic films were processed and analysed using a luxmeter. RESULTS: The radiation dose to the thyroid was higher in the 6-year-old phantom than in the 11-year-old phantom, for given exposure factors. In addition, there was an increase in dose in children's protocols compared with small adult protocols. CONCLUSION: Therefore, companies that develop PR equipment must develop child protocols for separate age groups that will consequently reduce the radiation dose in children, especially in their critical organs.
RESUMO
Ti6Al4V used in biomedical applications still has several surface-related problems, such as poor bone compatibility and low wear resistance. In this work, the formation of a protective layer of titanium nitride obtained by plasma treatment in hollow cathode was studied, and the best experimental conditions were verified by a statistical factorial design of experiments. The samples were characterized in terms of their physical and chemical properties, correlating the effects of time (min) and temperature (°C). An achieved ideal condition was further analysed in terms of in vitro cytotoxicity, micro-abrasion, and electrochemical properties. The carried-out assessment has shown that nitrided condition has an improvement in wettability, microhardness, along with TixNy formation and roughness increment, when compared to pristine condition.