NSmUfO NAOONAL DE I TECNOlOGlA I II~K nr ~-Tipo de Documento: ! i I DINT/N° MEMORIA TECNICA ( ) Apostila ( ) Artigo de periodico (x ) Artigo TecnicoCientifico ( ) Capitulo de Livro ( ) Disserta~ao ( ) Folheto ( ) Livro ( ) Monografia I ' ' I I I -Grau de sigilo: -Titulo: Bioactivity Improvement of Porous Titanium Samples via Biomimetic Method OLivre ORestrito I OConfidencial I-Data de Emlssao. I_N° de copias: ! W. S. Medeiros, M. C. Andrade, L. C. Pereira, M. V. Oliveira, C. A. A. Cairo. -Fonte: I, I -Resumo: I -Assinaturas: I I I I Autor(es): :,ICc,~, I Autorizo a reprodu~ao / digitaliza~ao deste trabalho: ( ) Sim ( ) Nao - Por que? I ' ( ) Nota Tecnica ( ) Patente ( ) Relatorio de Atividades ( ) Relatorio de Projeto ( ) Relatorio de Viagem ( ) Resposta Tecnica ( ) Relatorio Tecnico ( ) Tese -Sigla da UO: DCPM / LATEP I .. " I • 111II111111 11I11111111111' 1111 1111 Reg.63507 Bioactivity improvement Me 3985 Bioactivity Improvement of Porous Titanium Samples via Biomimetic Method Federal do Rio de Janeiro - UFRJ/PEMM/COPPE, CT/Bloco F/saia 210, Ilha do Fundao - Cidade Universitaria, Rio de Janeiro, [email protected] 2lnstituto Nacional de Tecnologia - INT/DPCM, Av. Venezuela nO 821602, Sallde, Rio de Janeiro, 2008]-3 ]2, [email protected] 3Centro Tecnico Aeroespacial - Instituto de Aeronautica e Espa<;o - CT A/IAEI AMR 4Centro de Tecnologia MineralCETEM 'Universidade Abstract - Porous titanium substrates were submitted to the biomimetic process in ordcr to improve its osteoconductivity. The samples were chcmically treated. hcat treated at 400 DCand 600 DCand soaked into a modified body fluid solution during periods from 2 to 28 days. Calcium phosphates were found on all samples. Titanium is known to be chemically stable in the human body. Porous titanium implants have been used in order to improve the interfacial resistance between the material and bone, providing a more efficient fixation of the implant. The bioactivation of this porous structure can be achieved through chemical and thermal pre-treatments I. The biomimetic process is employed both to evaluate the material biocompatibility and to obtain calcium phosphate coatings on metallic substrates. This process is based on the nucleation and growth of calcium phosphate films on a substrate immersed in body tluid solution (SBF) at 37°C. When it is associated with chemical and thermal pre-treatments of the substrate. the chemical adhesion of the calcium phosphate film increases2-J. The biomimetic approach presents advantages such as: the low temperature of the process. which is usable to any heat sensitive material. formation of bonelike apatite crystals with high bioactivity, deposition on and into porous surfaces and the possibility of bone growth stimulating factors incorporation4. The aim of this work is to apply the biomimetic process which has been widely used on smooth surface on a porous titanium substrate produced by powder metallurgy (figure I) in order to improve its osteoconductivit/. Porous titanium samples with about 63% of porosity were treated with a 1M NaOH solution at 130°C in an autoclave in order to form a sodium titanate hydrogel layer on the surface. The samples were heat treated at 400 °C and 600 DC for dehydration and stabilization of the titanate layer. The porous titanium substrates were submitted to modified body tluid solution (mSBF)-for 2, 7, 14 and 28 days to evaluate the evolution of calcium phosphate phase precipitation. The formation of a needlelike phase (figure 2) was observed after pre-treatments which is expected to be sodium titanate. After mSBF immersion. a phase rich with Ca and P was detected in the EDS expectrum of the sample soaked for just 2 days and also in other samples (7, 14,28 days). The sample soaked for 28 days exhibited a calcium phosphate coating morphology on the surface, showing the good potential of this process for coating this material. This research is currently in progress. and the next step will be the evaluation of the nature and morphology of the calcium phosphate tilm deposited on the porous titanium. Fig. I. Porous Ti micrograph of a sample with about 63% of porosity without pre-treatments. fig. 2. Porous Ti micrograph of a sample with chemical and thermal pre-treatments showing needles on the surlace. [I] H.Q. Nguyen, DA Deporter, R.M. Pilliar, N. Valiquette, R. Yakubovitch, Biomaterials 865-876, 25 (20041.  M. C. de Andrade, M. R. T. filgueiras and T. Ogasawara, J. Euro. ('eram. Soc. 505-510,22 (2002). 131 S fujibayashi. N. Masashi, H. M. Kim, T Kokubo, T. Nakamura, Biomalerials 443-450, 25 (2004). 141 P l1abibovie, f. Barrere, C. A. Van Blitterswijk, K. de Groot and P Layrolle, J. Am ('eram. Soc. 517-522. 85[3J (2002).