Estudo da anodização em novas ligas à base de Ti-15Zr-xMo para aplicação como implantes biomédicos
Carregando...
Arquivos
Data
2019-01-31
Autores
Sousa, Tiago dos Santos Pereira de
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O titânio e suas ligas são amplamente utilizados na fabricação de implantes dentários e ortopédicos, devido às suas propriedades mecânicas, eletroquímicas e biológicas superiores. As ligas Ti-15Zr-xMo foram desenvolvidas com elementos beta estabilizadores não citotóxicos, a fim de diminuir o módulo de Young (evitando o efeito de blindagem óssea) e reações adversas com os tecidos ósseos. No entanto, muito esforço foi feito para incluir propriedades bioativas em superfícies metálicas, tornando possível reduzir o tempo de cicatrização dos tecidos danificados, favorecendo o processo de osseointegração. Neste cenário, a oxidação por micro- arco (MAO) tem sido um tratamento de modificação de superfície de baixo custo, usado para alterar a morfologia e a composição de superfícies metálicas para aplicações biomédicas. Neste estudo, o tratamento MAO foi usado para criar um filme de óxido rico em Ca, P e Mg em ligas Ti-15Zr-xMo (x = 0, 5, 10 e 15% em peso), antes e após tratamentos térmicos, para uso como biomateriais. O tamanho e distribuição dos poros foram analisados por imagens SEM, análises de composição química da superfície foram realizadas por meio de medidas de XPS. Os resultados mostraram que os filmes de óxidos formados foram porosos, tendo que aspectos microestruturais (tamanho de grão e fases secundárias) afetadaram ligeiramente as características do filme (tamanho dos poros). Análises químicas indicaram que os filmes foram compostos preferencialmente por Ti e Zr, com incorporação de íons de Ca, P, Mg. Os filmes de óxidos nas ligas, obtidos pelo tratamento MAO, podem ser eficazes para serem utilizados em implantes osseointegráveis.
Titanium and its alloys are widely used for the manufacture of dental and orthopaedical implants, due their superior mechanical, electrochemical and biological properties. Ti-15Zr-xMo alloys have been developed with non-cytotoxic β-stabilizers elements, in order to decrease the Young’s modulus (avoiding the stress shielding effect) and adverse reactions with bone tissues. However, much efforts have been taken to include bioactive properties in metallic surfaces, in order to reduce the healing time of damaged tissues, thus fasten the osseointegration process. In this scenery, micro-arc oxidation (MAO) has been a low-cost surface modification treatment, which is used to change the morphology and composition of metallic surfaces for biomedical applications. In this study, MAO treatment was used to create a Ca, Mg and P-rich oxide film in Ti-15Zr-xMo (x = 0, 5, 10 and 15 wt%), before and after heat treatment of the alloys for use as biomaterials. Surface chemical composition of the films was evaluated by XPS and EDS measurements. Morphology was analyzed by SEM images. The results showed that the oxide films were thick and porous, with microstructural aspects (grain size and secondary phases) slightly affecting the characteristics of the film (pore size, thickness and roughness). The heat treatment did not influence the microstructure of the film. Chemical analysis indicated that the films were composed mainly by Ti and Zr, with the incorporation of ions of Ca, P and Mg. Oxide films in the alloys obtained by the MAO treatment may be effective for use in osseointegrative implants.
Titanium and its alloys are widely used for the manufacture of dental and orthopaedical implants, due their superior mechanical, electrochemical and biological properties. Ti-15Zr-xMo alloys have been developed with non-cytotoxic β-stabilizers elements, in order to decrease the Young’s modulus (avoiding the stress shielding effect) and adverse reactions with bone tissues. However, much efforts have been taken to include bioactive properties in metallic surfaces, in order to reduce the healing time of damaged tissues, thus fasten the osseointegration process. In this scenery, micro-arc oxidation (MAO) has been a low-cost surface modification treatment, which is used to change the morphology and composition of metallic surfaces for biomedical applications. In this study, MAO treatment was used to create a Ca, Mg and P-rich oxide film in Ti-15Zr-xMo (x = 0, 5, 10 and 15 wt%), before and after heat treatment of the alloys for use as biomaterials. Surface chemical composition of the films was evaluated by XPS and EDS measurements. Morphology was analyzed by SEM images. The results showed that the oxide films were thick and porous, with microstructural aspects (grain size and secondary phases) slightly affecting the characteristics of the film (pore size, thickness and roughness). The heat treatment did not influence the microstructure of the film. Chemical analysis indicated that the films were composed mainly by Ti and Zr, with the incorporation of ions of Ca, P and Mg. Oxide films in the alloys obtained by the MAO treatment may be effective for use in osseointegrative implants.
Descrição
Palavras-chave
Física, Ciência dos materiais, Ligas de titânio, Modificação de superfícies, Physics, Materials science, Titanium alloys, Surface modification