Biocerâmica

FABRICAÇÃO DE BIOCERÂMICAS POROSAS
DE HIDROXIAPATITA POR GELCASTING
Flávia Mendonça Fonseca, Marcelo Henrique Prado da Silvaa, Luís Henrique Leme Louro,
Carlos Roberto Corrêa da Costaa
Seção de Engenharia Mecânica e de Materiais – Instituto Militar de Engenharia; Praça General
Tibúrcio, 80, 22290-270, Rio de Janeiro/RJ, Brasil. a ABSTRACT
Gelcasting is a processing route that enables the production of ceramic bodies with complex shapes and different densities. Therefore, this is a way to prepare porous ceramics with good interconnectivity. This is highly desirable for bone regeneration applications, since interconnected pores promote cell migration, nutrient diffusion and vascularization of newly formed tissue. In the present study, nanometric apatite powders were produced. Nanometric ceramic powders were mixed to monomers (methacrylamide and methylenebisacrylamide), a dispersant (dispersal
130) and a surfactant (Genaminox KC) to produce porous test samples. Polyethylene spheres were introduced during processing in order to keep the pores interconnected. The samples were sintered at different temperatures and the phases hydroxyapatite, α-TCP and β- TCP were observed. The results show that the volume fractions of the phases depend of powder synthesis conditions and on the sintering temperature. The fraction of polyethylene spheres and the sintering temperature directly affect the formation of mechanically stable interconnected pores.
RESUMO
Gelcasting é uma rota de conformação cerâmica que viabiliza a produção de corpos com formas complexas e densidades diferentes. Portanto, esta via é indicada para se obter estruturas cerâmicas porosas com possibilidade de controle de tamanho e interconectividade dos poros. Esta característica é altamente desejada para fins de regeneração óssea por favorecer a migração celular, difusão de nutrientes e vascularização dos tecidos recém formados. Neste trabalho, foram usados pós nanométricos de apatita. Os pós