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3D Printing Technologies in Metallic Implants
Table 1. Various AM technologies in medical applications and their advantages and disadvantages reproduced (Reprinted from 3D and
4D Printing of Polymer Nanocomposite Materials, Sinha SK, Additive manufacturing (AM) of medical devices and scaffolds for tissue
engineering based on 3D and 4D printing, pp 119-160, Copyright (2020), with permission from Elsevier) [61]
Technique Pros Cons References
Vat • High resolution • Shrinkage and heat effects [62-68]
photopolymerization • Enhanced mechanical property • Material limitation
and Selective laser • Able to print high-density cells • Require a UV source
sintering • Suitable for many photocurable polymers • Toxicity due to near UV blue light
• The raw material base is a fluid • Cell damage
• Complex structure formation through • Limitations in multicomponent cells
power bed • Thermal damage during the
• Biomaterial deposition in the solid or liquid procedure
phase
• Able to use ceramic materials
Stereolithography • Great resolution and fast production • Common for photopolymers [69]
• Independency of printing time to complexity • UV blue light is toxic to cells
• Nozzle-free technique • Multicell printing is not possible
Powder fusion • High range of materials (metals, polymers, • Microfractures and voids [61,63]
printing (PFP) etc.) • Crack generation
• Excellent mechanical strength • Hard to produce horizontal gradients
• Complex geometries • Need post processing
• Powder recycling • High power usage
• Thermal distortion
Extrusion printing • High simplicity • Low speed [66,70,71]
• Excellent controlling • Only applicable for viscous liquids
• Capability to print both physical and • Should control the material usage
compositional gradients and other factors
• Capability to print cells and bioactive factors • Require binder/polymer removal
• Able to print polymers, metals, and ceramic at high temperature followed by
parts sintering
Directed energy • The raw material platform is solid polymers • Expensive procedure [64-67,72]
deposition • High resolution • Possibility of thermal damages
• No need to powder bed • Poor part resolution and tolerances
• Able to easily print multi-material structures
along with compositional gradient
Sheet lamination • Speed, low cost, ease of material handling • Just for layered laminates [64-67,73]
• Formation of layered laminate structure • Post-processing is needed
• Possibility to print hydroxyapatite, zirconia, • The strength and integrity of models
various cells are reliant on the adhesive used
• May require post-processing
• Limited material use
Indirect 3D printing • Suitable for prototyping/preproduction • Low resolution [74]
• Applicable for various materials • Time-consuming
• Requirement for dedicated waxes for
biocompatibility and molds for casting
Inkjet printing • Applicable for wide range of biomaterials • Toxic nature [74,75]
• Without any need to support structural • Compared to SLS, low mechanical
complexities strength
• High-speed • Expensive setup
• Coprinting the multiple solution compositions • Low applicable material range
• It can simultaneously print bioactive composites • Continuous procedures are not possible
• Materials with low viscosity can be • Low cell density
printed • Clogging of the head issues
(Contd...)

30 International Journal of Bioprinting (2021)–Volume 7, Issue 7