PAREDES, WILBER E.B.ARI, SANDRA F.GERALDO, AUREA B.C.ANDRADE, DELVONEI A. de2016-12-202016-12-20PAREDES, WILBER E.B.; ARI, SANDRA F.; GERALDO, AUREA B.C.; ANDRADE, DELVONEI A. de. In vitro study of the composition and microhardness of the hard tissues from oral cavity submitted to gamma irradiation. In: WORLD CONGRESS ON CANCER THERAPY, 15th, December 5-7, 2016, Philadelphia, USA. <b>Proceedings...</b> DisponÃvel em: http://repositorio.ipen.br/handle/123456789/26920.http://repositorio.ipen.br/handle/123456789/26920Introduction: Clinical Radiotherapy is one of the most important techniques for the treatment of malignant lesions of the head and neck, however, exposure to ionizing radiation can lead to systemic complications or sites during and after radiation treatment. Among these immediate local complications in oral cavity, it stands out the xerostomia and consequent oral mucositis. Regarding late complications produced by radiation, decay of radiation and osteoradionecrosis, both dose-dependent lesions, which mostrate a high level of incidence in recent decades (1-30%) and unwieldy, although these are presented after completion of treatment and under the influence of local factors. Methodology: The methodology proposed in this study aims to examine the direct effect of ionizing radiation after gamma irradiation of enamel, root dentin and jawbone samples, through the dose rate used in patients suffering with head and neck cancer. The samples were analyzed by microhardness surface analysis, scanning electron microscopy (SEM) and Fourier transform infrared spectrometry (FTIR) before and after irradiation. Results and discussion: The data were analyzed statistically with a significance level of 95% (p <0.05%), through the parametric Student's t-test for related averages and ANOVA statistical test, finding a statistically significant result (p = 0.00) for the four groups of samples. Conclusion: From the statistical results, it is concluded that the effect of gamma radiation on hard tissues of the oral cavity was highly significant regarded to physical, compositional and morphological properties.openAccessin vitromicrohardnessanimal tissuesoral cavitygamma radiationradiotherapyionizing radiationsbiological radiation effectsenamelsdentinneoplasmsscanning electron microscopyspectroscopyclinical trialsswineanimalsskeletonbone tissuesteethosteoradionecrosisjawIn vitro study of the composition and microhardness of the hard tissues from oral cavity submitted to gamma irradiationTexto completo de eventohttps://orcid.org/0000-0002-6689-3011