RESUMEN
Zn-based biodegradable alloys or composites have the potential to be developed to next-generation orthopedic implants as alternatives to conventional implants to avoid revision surgeries and to reduce biocompatibility issues. This review summarizes the current research status on Zn-based biodegradable materials. The biological function of Zn, design criteria for orthopedic implants, and corrosion behavior of biodegradable materials are briefly discussed. The performance of many novel zinc-based biodegradable materials is evaluated in terms of biodegradation, biocompatibility, and mechanical properties. Zn-based materials perform a significant role in bone metabolism and the growth of new cells and show medium degradation without the release of excessive hydrogen. The addition of alloying elements such as Mg, Zr, Mn, Ca, and Li into pure Zn enhances the mechanical properties of Zn alloys. Grain refinement by the application of post-processing techniques is effective for the development of many suitable Zn-based biodegradable materials.
RESUMEN
Titanium-ceramic composites are potential implant material candidates because of their unique mechanical properties and biocompatibility. This review focused on the latest advancement in processing of titanium-ceramic materials. Previously, titanium-ceramic incorporated using different coating techniques, i.e., plasma spraying and electrophoretic depositions, to enhance the biocompatibility of the implants. A major drawback in these coating methods is the growth of tissue at only the surface of the composite and might peel off over time. Recently, metal-ceramic composite was introduced via powder metallurgy method such as powder injection moulding. A porous structure can be obtained via powder metallurgy. Producing a porous titanium-ceramic structure would improve the mechanical properties, biocompatibility and tissue growth within the structure. Hence, further research needed to be done by considering the potential of powder injection moulding method which offer lower costs and more complex shapes for future implant.