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International Journal of Bioprinting 3D-printed biodegradable metals for bone regeneration

Table 1. Comparison of the advantages and disadvantages of 3D printing methods
Materials Name of technology Advantages Disadvantages References
Biodegradable metal Powder bed fusion High precision, high controllability, Metal oxidation, sputtering, and 77-80
suitable for metallic materials vaporization in the manufacturing
process
Direct energy deposition High efficiency, material saving, Need to add auxiliary support 84,85
low cost structure, low precision, lack of heat
dissipation media caused by stress
build up
Material extrusion Printing process can be carried out at Need to add auxiliary support 98-100
room temperature structure, low mechanical strength,
adhesive residue may exist
Binder jetting Printing process can be carried out at Low mechanical strength 102-105
room temperature, can be used without
adhesives, can print larger components
3D weaving No heat treatment required High cost and manufacturing 109
difficulty
Hybrid materials Fused deposition Wide range of materials, have both Lower mechanical strength than 133,186,188-190
modeling, cryogenic plasticity and bioactivity metals
deposition
3D printing, etc.

due to the high melting point of magnesium at 650°C, the structure several times during the fabrication process,
which is close to its boiling point (1091°C), vaporization is avoiding material waste and decreasing costs. 86,87 The
highly likely to occur during fabrication using PBF. 77 advantages of DED include the high density mechanical
properties of the finished product, high efficiency,
Scaffolds fabricated using PBF have high fineness and
a wide variety of materials to achieve excellent fabrication material savings, low cost, and suitability for printing
large components. Furthermore, DED can be used to
87
effects. 79,80 The high precision and controllability of PBF add structures to existing components, such as by adding
are essential for controlling the pore size of porous hard surfaces to enhance the mechanical strength of the
scaffolds, where pores larger than 100 µm promote component. The disadvantages of these methods include
88
osteogenesis and angiogenesis, and micropores the need to add auxiliary support structures during the
smaller than 20 µm can be utilized to achieve a more printing process, lower precision, rough surface structures,
homogeneous distribution of neoplastic bone through and the lack of a heat dissipation medium (e.g., loose metal
capillary action and, by facilitating cellular recruitment powder) around the component, which can easily lead to
81
and attachment, stimulate mineralization. Scaffolds stress buildup. 85,87,89
with both macropores and micropores have optimal
bone-enhancing effects. In addition, scaffolds with high The higher density and lower porosity allow the
82
fidelity can provide more adequate support for bone fabrication of components with higher mechanical
defect healing, and the precise arrangement of cells and strength when using DED than when using other printing
drugs loaded in the scaffolds can also result in superior methods; for instance, DED-printed 316L stainless steel
bone regeneration promotion. 83 components are similar in strength to those prepared by
conventional fusion casting. These properties allow DED
90
3.2. Three-dimensional printing of BMs by direct to retain the high mechanical properties of the material
energy deposition while incorporating a flexible shape that can provide more
Direct energy deposition is used to manufacture parts adequate support for bone regeneration. 91,92 Moreover,
by melting powdered materials as they are deposited; although the surface of DED-produced components is
the most commonly used method is wire arc additive rough, a smooth surface can be obtained by treating the
manufacturing (WAAM). A metal powder is ejected from components, and the components can also be endowed with
a nozzle into a vacuum or inert gas environment, while an a microscopic rough texture by specific means to increase
electron beam is used as a heat source to melt the powder the levels of osteoprotegerin, transforming growth factor
and sinter it, thus printing components layer by layer. 84,85 beta 1 (TGF-β1), VEGF-A, FGF-2, and angiopoietin-1 in
Scaffolds fabricated using DED can be added to modify osteoblasts, which can promote bone regeneration. 93-96

Volume 10 Issue 3 (2024) 43 doi: 10.36922/ijb.2460