Development of nanostructured titanium implants for biomedical implants-A short review

Implants for bio medical applications have undergone rapid and dramatic developments in the past two decades. From the point of bio-compatibility, titanium (Ti) is superior to other metallic materials due to the formation of a stable passive layer of TiO2 on its surface. Another favorable properties of Ti are the low elastic modulus, light-weight than other surgical metals, and produce fewer artifacts on computer tomography (CT) and magnetic resonance imaging (MRI). Ti-6Al-4 V (Ti64) is the most widely used surgical Ti alloy. Despite the excellent passivity and corrosion resistance of Ti64, elevated concentrations of metal ions were detected in the tissues around the implants, questions the long-term safety of Ti64 alloy implants. An alternative approach to overcome the problem of harmful ion release is to use pure titanium. However, the mechanical properties of commercially pure (CP) Ti are not as good as Ti64. Severe Plastic Deformation processing provides an opportunity for refining the grains of conventional bulk solids to produce grain sizes within the sub-micrometer or even the nanometer range with higher strength, bioactivity and antibacterial properties. Equal channel angular pressing (ECAP) is a promising and efficient method for the production of bulk ultrafine-grained or nanostructured material with excellent biocompatibility and extraordinary mechanical properties. There have been reports of dental implant fractures in clinical practice, but the success rate of restoration is limited since for the dental and maxillofacial implants, nanostructured CPTi should have, in addition to high strength, and increased fatigue life, even at the locations with stress concentrators. Therefore, the mechanical properties especially fatigue strength of CPTi in clinical practice need to be improved. This short review briefly focuses on the suitability of ECAPed CPTi for medical implants. (c) 2021 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of the scientific committee of the 28th International Conference on Processing and Fabrication of Advanced Materials.