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La fabricación aditiva permite el diseño y la personalización de implantes osteoarticulares, una característica fundamental en la cada vez más creciente medicina personalizada. La aleación de CoCrMo es una de las más utilizadas en la fabricación de prótesis. El creciente aumento de prótesis implantadas se traduce también en un incremento del número de infecciones cuyas complicaciones pueden ser devastadoras. La adherencia bacteriana constituye el paso previo al desarrollo de biopelículas y de la infección. En este trabajo se evalúa la influencia del proceso de fabricación de la aleación de CoCrMo en la adherencia bacteriana de S. aureus ATCC 29213, S. epidermidis ATCC 35984, E. coli ATCC 25922 y P. aeruginosa ATCC 27853. Los resultados revelaron que la adherencia bacteriana era significativamente menor (33,3%, 9,7%, 11,2% y 27,1% para S. aureus, S. epidermidis, E. coli y P. aeruginosa, respectivamente) en las muestras de aleación de CoCrMo fabricada por sinterización directa por láser (DMLS) en comparación con una aleación comercial.

Ti–6Al–4V ELI scaffolds produced by additive manufacturing and functionalized by anodizing technique in two different conditions have been evaluated using scanning electron microscopy, energy-dispersive X-ray spectroscopy, optical confocal microscopy, cyclic potentiodynamic polarization curves (CPP), and electrochemical impedance spectroscopy (EIS). Despite the differences in composition and morphological features between the anodic layers grown, the results revealed an improvement of the corrosion resistance in both anodized conditions regarding non-anodized samples. The non-anodized scaffolds presented pitting corrosion in phosphate-buffered saline solution at 37 °C. Conversely, the anodized samples prevented pitting corrosion and enhanced barrier properties by decreasing the passive current density in two orders of magnitude. EIS data show, anodized scaffolds presented good stability after 168 h of immersion time and better protective properties than non-anodized samples.

Additive manufacturing is a recent tool in medicine able to fabricate scaffolds to replace or regenerate bone tissues. The process permits the user to control scaffolds parameters such as size, unit cell, porosity, wall thickness, etc. However, the use of these three-dimensional geometries might negatively affect their corrosion behaviour. This paper studies the influence of Ti-6Al-4V ELI scaffold unit cell and, geometry size on the electrochemical response. Three different types of scaffold unit cell and three different geometry sizes were fabricated by additive manufacturing technique. The porosity of the scaffolds was studied by X-ray microtomography while surface changes, by scanning electron microscopy. Electrochemical behaviour was evaluated by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) in a phosphate buffered saline solution at 37 °C. Potentiodynamic polarization curves show that scaffolds showed a higher pitting susceptibility than solid samples at potentials higher than 1 V. EIS spectra show that the scaffolds geometry size promotes narrowing of the maximum phase angle at the high frequency range (10-10) due to a non-homogeneous distribution of current and potential.

Direct Metal Laser Sintering (DMLS) technique allows the manufacturing a wide variety of medical devices for any type of prosthetic surgery (HIP, dental, cranial, maxillofacial) as well as for internal fixation devices (K-Wires or Steinmann Pins). There are a large number of research studies on DMLS, including microstructural characterization, mechanical properties and those based on production quality assurance but the influence of porosity in the corrosion behavior of these materials not been sufficiently considered. In the present paper, surgical pins of Ti6Al4V have been produced by DMLS. After testing in a phosphate buffered saline solution, the surface of the titanium alloy appeared locally covered by a voluminous white oxide. This unexpected behavior was presumably due to the existence of internal defects in the pins as result of the manufacturing process. The importance of these defects—that might act as crevice nucleation sites- has been revealed by electrochemical techniques and confirmed by computed tomography.

© 2015 Elsevier Ltd. Direct metal laser sintering (DMLS) is a powerful tool to produce titanium based biomaterials because the ease to convert 3D medical imaging data into solid objects with excellent mechanical and corrosion properties. DMLS samples can be functionalized by anodizing, allowing the growth of titanium oxide layers of enhanced properties. In the present paper, a complete characterization of the microstructure, mechanical properties and particularly, the corrosion behavior has been carried out to assess their possible use as biomaterial. The results of the anodized scaffolds are very promising, showing a Young Modulus near to the cortical bone and a low corrosion rate, ensuring their suitability for medical applications.