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Bisfenol A (BPA) : sua presença nos compósitos e sistemas adesivos
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Abstract(s)
O bisfenol A (BPA) é um dos produtos químicos de maior volume produzidos em todo o mundo. Ele é utilizado, por exemplo, na produção de resinas epóxi e de plásticos de policarbonato os quais que se encontram em muitos produtos de consumo.
Vários estudos, realizados em humanos, mostraram níveis mensuráveis de BPA nos fluídos corporais, sendo encontrado em adultos, crianças e também grávidas.
Com uma estrutura muito semelhante à dos estrogénios, ele foi classificado como um desregulador endócrino. Por causa da sua presença, vários efeitos foram observados, desde alterações comportamentais, cardiovasculares, no aparelho reprodutor, e até na cavidade oral.
Na área da medicina dentária, os monómeros mais encontrados são a família dos di-metacrilatos da qual o bis-GMA e seus derivados são mais usados. Presentes maioritariamente na parte orgânica das resinas compostas também se pode encontrar em quantidade inferior na parte resinosa dos adesivos.
Precauções, por parte do médico dentista, podem ser tomadas para reduzir grande parte da libertação do BPA após colocação do material restaurador no paciente.
No entanto, novas alternativas estão presentes no mercado, que resolvem à partida a questão dos desreguladores endócrinos por não conter derivados de BPA nas suas composições. Essas alternativas, revelam propriedades promissoras.
Bisphenol A (BPA) is one of the highest volume chemicals produced worldwide. It is used, for example, in the production of epoxy resins and polycarbonate plastics which are found in many consumer products. Several human studies have shown measurable levels of BPA in body fluids. Found in adults, children, and also pregnant women. With a structure very similar to the estrogens, it has been classified as an endocrine disruptor. Because of its presence, several effects were observed, from behavioral changes, cardiovascular, reproductive system, even in the oral cavity. In the area of dentistry, the most common monomers are the family of dimethacrylates from which bis-GMA and its derivatives are most often used. Present mainly in the organic part of composite resins, they can also be found in smaller quantities in the resinous part of adhesives. The dentist can take some precautions to reduce much of the BPA release after placement of the restorative material in the patient. However, new alternatives are on the market, which resolve the issue of endocrine disruptors in the first place, as they do not contain BPA derivatives in their compositions. These alternatives reveal promising properties.
Bisphenol A (BPA) is one of the highest volume chemicals produced worldwide. It is used, for example, in the production of epoxy resins and polycarbonate plastics which are found in many consumer products. Several human studies have shown measurable levels of BPA in body fluids. Found in adults, children, and also pregnant women. With a structure very similar to the estrogens, it has been classified as an endocrine disruptor. Because of its presence, several effects were observed, from behavioral changes, cardiovascular, reproductive system, even in the oral cavity. In the area of dentistry, the most common monomers are the family of dimethacrylates from which bis-GMA and its derivatives are most often used. Present mainly in the organic part of composite resins, they can also be found in smaller quantities in the resinous part of adhesives. The dentist can take some precautions to reduce much of the BPA release after placement of the restorative material in the patient. However, new alternatives are on the market, which resolve the issue of endocrine disruptors in the first place, as they do not contain BPA derivatives in their compositions. These alternatives reveal promising properties.
Description
Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas Moniz
Keywords
BPA Bisfenol A Compósitos Adesivos