A. Rodriguez-Contreras et al. Powder metallurgy with space holder for porous titanium implants: A review. Journal of Materials Science & Technology

A. Rodriguez-Contreras, M. Punset, J.A. Calero, F.J. Gil, E. Ruperez, J.M. Manero. Powder metallurgy with space holder for porous titanium implants: A review. Journal of Materials Science & Technology Volume 76, 20 June 2021, Pages 129-149.

doi: doi.org/10.1016/j.jmst.2020.11.005.

Abstract

One of the biggest challenges in the biocompatibility of implantable metals is the prevention of the stress shielding effect, which is related to the coupling of the bone-metal mechanical properties. This stress shielding phenomenon provokes bone resorption and the consequent adverse effects on prosthesis fixation. However, it can be inhibited by adapting the stiffness of the implant material. Since the use of titanium (Ti) porous structures is a great alternative not only to inhibit this effect but also to improve the osteointegration of orthopedic and dental implants, a brief description of the techniques used for their manufacturing and a review of the current commercialized implants produced from porous Ti assemblies are compiled in this work. As powder metallurgy (PM) with space holder (SH) is a powerful technology used to produce porous Ti structures, it is here discussed its potential for the fabrication of medical devices from the perspectives of both design and manufacture. The most important parameters of the technique such as the size and shape of the initial metallic particles, the SH and binder type of materials, the compaction pressure of the green form, and in the sintering stage, the temperature, atmosphere, and time are reviewed according to the bibliography reported. Furthermore, the importance of the porosity and its types together with the influence of the mentioned parameters in the final porosity and, consequently, in the ultimate mechanical properties of the structure are discussed. Finally, a few examples of the PM-SH application for the manufacturing of orthopedic implants are presented.