RESUMO
This paper deals with the surface modification of titanium by sodium-ion implantation and with the effect of this modification on structure, corrosion resistance, bioactivity and cytocompatibility. The Na ions were implanted with doses of 1 x 10(17) and 4 x 10(17) ions/cm(2) at an energy of 25 keV. The chemical composition of the surface layers formed during the implantation was examined by secondary-ion mass spectrometry (SIMS) and X-ray photoelectron spectroscopy (XPS), and their microstructure--by transmission electron microscopy (TEM). The corrosion resistance was determined by electrochemical methods in a simulated body fluid (SBF) at a temperature of 37 degrees C, after exposure in SBF for various times. The surfaces of the samples were examined by optical microscopy, by scanning electron microscopy (SEM-EDS), and by atomic force microscopy (AFM). Biocompatibility of the modified surface was evaluated in vitro in a culture of the MG-63 cell line and human osteoblast cells. The TEM results indicate that the surface layers formed during the implantation of Na-ions are amorphous. The results of the electrochemical examinations obtained for the Na-implanted titanium samples indicate that the implantation increases corrosion resistance. Sodium-ion implantation improves bioactivity and does not reduce biocompatibility.
Assuntos
Íons , Osteoblastos/citologia , Sódio/química , Titânio/química , Materiais Biocompatíveis/química , Líquidos Corporais , Linhagem Celular Tumoral , Corrosão , Humanos , Espectrometria de Massas/métodos , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão/métodos , Espectrometria por Raios X/métodos , Propriedades de SuperfícieRESUMO
The paper compares the effects of various surface modifications, ion implantation, alkaline treatment and anodic oxidation, upon the corrosion resistance and bioactivity of titanium. The chemical composition of the surface layers thus produced was determined by XPS, SIMS and EDS coupled with SEM. The structure of the layers was examined by TEM, and their phase composition by XRD. The corrosion resistance was determined by electrochemical methods after the samples were exposed to the test conditions for 13 h. The bioactivity of titanium was evaluated in a simulated body fluid at a temperature of 37 degrees C after various exposure time.
Assuntos
Próteses e Implantes , Titânio , Eletrodos , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Oxirredução , Espectrometria de Massa de Íon Secundário , Propriedades de SuperfícieRESUMO
This study is concerned with the effect of dual implantation of calcium and phosphorus upon the structure, corrosion resistance and biocompatibility of titanium. The ions were implanted in sequence, first Ca and then P, both at a dose of 10(17) ions/cm2 at a beam energy of 25 keV. Transmission electron microscopy was used to investigate the microstructure of the implanted layer. The chemical composition of the implanted layer was examined by XPS and SIMS. The corrosion resistance was determined by electrochemical methods in a simulated body fluid (SBF) at a temperature of 37 degrees C. The biocompatibility tests were performed in vitro in a culture of human-derived bone cells (HDBC) in contact with the tested materials. The viability of the cells was determined by an XTT assay and their activity by the measurements of the alkaline phosphatase activity in contact with implanted and non-implanted titanium samples. The in vitro examinations confirmed that, under the conditions prevailing during the experiments, the biocompatibility of Ca + P ion-implanted titanium was satisfactory. TEM results show that the surface layer formed by the Ca + P implantation is amorphous. The corrosion resistance of titanium, examined by the electrochemical methods, appeared to be increased after the Ca + P ion implantation.
Assuntos
Materiais Biocompatíveis/química , Osso e Ossos/citologia , Cálcio/química , Íons , Fósforo/química , Titânio/química , Fosfatase Alcalina/metabolismo , Líquidos Corporais , Osso e Ossos/metabolismo , Fosfatos de Cálcio/química , Sobrevivência Celular , Células Cultivadas , Corrosão , Eletroquímica , Ensaio de Imunoadsorção Enzimática , Humanos , Técnicas In Vitro , Indicadores e Reagentes/farmacologia , Teste de Materiais , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Temperatura , Sais de Tetrazólio/farmacologiaRESUMO
This work presents data on the structure and corrosion resistance of titanium after phosphorus-ion implantation with a dose of 10(17)P/cm2. The ion energy was 25keV. Transmission electron microscopy was used to investigate the microstructure of the implanted layer. The chemical composition of the surface layer was examined by X-ray photoelectron spectroscopy and secondary ion mass spectrometry. The corrosion resistance was examined by electrochemical methods in a simulated body fluid at a temperature of 37 C. Biocompatibility tests in vitro were performed in a culture of human derived bone cells in direct contact with the materials tested. Both, the viability of the cells determined by an XTT assay and activity of the cells evaluated by alkaline phosphatase activity measurements in contact with implanted and non-implanted titanium samples were detected. The morphology of the cells spread on the surface of the materials examined was also observed. The results confirmed the biocompatibility of both phosphorus-ion-implanted and non-implanted titanium under the conditions of the experiment. As shown by transmission electron microscope results, the surface layer formed during phosphorus-ion implantation was amorphous. The results of electrochemical examinations indicate that phosphorus-ion implantation increases the corrosion resistance after short-term as well as long-term exposures.
Assuntos
Materiais Biocompatíveis/farmacologia , Fósforo/química , Fósforo/farmacologia , Titânio , Materiais Biocompatíveis/química , Osso e Ossos/citologia , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/ultraestrutura , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Corrosão , Humanos , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , PotenciometriaRESUMO
This work presents data on the structure and corrosion resistance of titanium after calcium-ion implantation with a dose of 10(17) Ca+/cm2. The ion energy was 25 keV. Transmission electron microscopy was used to investigate the microstructure of the implanted layer. The chemical composition of the surface layer was examined by XPS and SIMS. The corrosion resistance was examined by electrochemical methods in a simulated body fluid (SBF) at a temperature of 37 degrees C. Biocompatibility tests in vitro were performed in a culture of human derived bone cells (HDBC) in direct contact with the materials tested. Both, the viability of the cells determined by an XTT assay and activity of the cells evaluated by alkaline phosphatase activity measurements in contact with implanted and non-implanted titanium samples were detected. The morphology of the cells spread on the surface of the materials examined was also observed. The results confirmed the biocompatibility of both calcium-ion-implanted and non-implanted titanium under the conditions of the experiment. As shown by TEM results, the surface layer formed during calcium-ion implantation was amorphous. The results of electrochemical examinations indicate that calcium-ion implantation increases the corrosion resistance, but only under stationary conditions; during anodic polarization the calcium-ion-implanted samples undergo pitting corrosion. The breakdown potential is high (2.7-3 V).
