1 - Metallic scaffolds manufactured by selective laser melting for biomedical applications

Abstract

Additive manufacturing (AM) has emerged as a promising technique for fabricating customized tissue engineering scaffolds and implants. The scaffolds not only act as temporary support structures for bone ingrowth and tissue regeneration but also provide temporary biological functions. The complex defect sites in human knee, dental, hip, skull, and craniofacial require a precise design of scaffold to match and fit in those defect sites. These scaffolds are designed to stay in the human body as implants for longer periods. This requires matching of mechanical properties and biocompatibility of these scaffolds with surrounding hard tissues. Extensive research has been carried out to provide patients with productive and cost-effective solutions by fabricating complex and near net shape metallic scaffolds using the potential of laser-assisted AM techniques, ie, selective laser sintering (SLS) and selective laser melting (SLM). This chapter focuses on the development of metallic scaffolds and implants using such laser-assisted AM techniques. For this reason, discussion on SLS is limited to fundamentals, as this particular AM technique is not useful for fabricating metallic scaffolds. However, the discovery of SLS laid the foundation for the development of SLM by incorporating high-energy lasers, which are useful for developing near net shape and complicated metallic scaffolds with minimum defects in their microstructures. SLM has been explored exclusively for fabricating tissue engineering scaffolds and implants from a wide range of metals. This chapter elucidates the key processing parameters of SLM and their effects on the functionality of fabricated scaffolds. The progress, limitations, challenges, and potential of SLM in the manufacturing of metallic scaffolds and implants are also explained. An overview of the research gaps and future research directions is provided.