Calcium analysis from gamma sterilized human dentin and enamel
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2019
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ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42.
Resumo
Gamma radiation changes the patients0 oral cavity undergoing radiotherapy. Alterations cause an unsaturated
environment of calcium and phosphate into the oral cavity. After approval of the Ethics Committee, 20 hu-
man teeth were sectioned to obtain 20 human enamel and 20 dentin samples, polished plane. Samples were
randomized in the irradiated group and control group (untreated). Then, the treatment group was irradiated
with 25:0 kGy at the 60Co multipurpose irradiator. After the gamma irradiation, Fourier Transformed Infrared
Spectroscopy (FTIR), percentage of surface microhardness loss (%SMHL) and Scanning Electron Microscopy
(SEM) were performed. At the end, acidic biopsies were performed to quantify the concentration of calcium
present in the samples. FTIR showed that the molecular structure of HA of the enamel is similar to the non-
irradiated, with no formation or loss of molecular compounds occurring. X-ray °uorescence at enamel samples
was performed. Microscopic morphological analysis did not shown signi¯cant di®erences. Surface microhardness
is an indirect indicator of the mineral content of the samples. The mean obtained was 258:2 (38:8) KHN within
the hardness spectrum of the healthy natural enamel. The compounds present in the samples and the values of
the ratios of Calcium and Phosphate oxides and relation between the elements Calcium and Phosphorus. The
ratio of the most stable oxides shows a variation with linear correlation. In the enamel, the ratio (Ca/P) shows
a change in the elemental content with linear correlation (R2 = 1). These ¯ndings lead us to a new hypothesis
of behaviour of the HA crystal versus gamma irradiation. On the other hand for the irradiated dentin, the
Knoop hardness number was within the range of the spectrum similar to that of natural dentin of human origin.
X-ray °uorescence shows that irradiated dentin has great similarity with natural dentin from the point of view
of chemical composition. SEM analyses showed that there was no thermal damage or interprismatic morpho-
logical changes in the hydroxyapatite structure of human dental dentin outside the buccal environment when
using doses of gamma irradiation up to 25 kGy.
Como referenciar
ZAMATARO, CLAUDIA B.; KUCHAR, NIELSEN G.; SCAPIN, MARCOS A.; ZANINI, NATHALIA; CASTRO, PEDRO; RABELO, THAIS F.; JUVINO, AMANDA C.; ZEZELL, DENISE. Calcium analysis from gamma sterilized human dentin and enamel. In: ENCONTRO DE OUTONO DA SOCIEDADE BRASILEIRA DE FÍSICA, 42., 26-31 de maio, 2019, Aracaju, SE. Resumo... São Paulo: Sociedade Brasileira de Física, 2019. Disponível em: http://repositorio.ipen.br/handle/123456789/30214. Acesso em: 28 Mar 2024.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.