Table 2.

Advantages, disadvantages and applications of biodegradable and non-biodegradable metallic materials

Classification	Materials	Advantages	Disadvantages	Applications	References
Biodegradable metallic materials	Mg-based alloys	Biocompatible Biodegradable Bioresorbable Similar density and Young’s modulus of bone (E = 10–30 GPa) Less stress-shielding effect Light weight	Hydrogen evolution during degradation Less resistance to corrosion	Bone screws, bone plates, bone pins, etc	Chandra and Pandey (2020)
	Fe-based alloys	High tensile strength and formability, fair biocompatibility, MRI compatible (austenitic phase), and no H2 gas production during degradation	Very low degradation rate, high elastic modulus; degradation via 2Fe + 2H2O + O2 → 2Fe(OH)2	Temporary cardiovascular and orthopaedic implants	Seitz et al. (2015)
	Zn-based alloys	Intermediate corrosion rate (falling between corrosion rates of Mg and Fe), fair biocompatibility, no H2 gas evaluation and non-toxic corrosion products, good processability, low melting point, and less reactivity in molten state	Low mechanical strength, age hardening; degradation by 2Zn + 2H2O + O2	Wound closure devices (biodegradable staples, surgical tacks, plugs, microclips, and rivets), orthopaedic fixation devices (fixative plates, screws, and porous scaffolds), cardiovascular stents, and bone implants	Dambatta et al. (2015)
Non-biodegradable metallic materials	316L Stainless steel	Easily available and low cost Excellent fabrication properties Accepted biocompatibility and toughness	High modulus Poor corrosion resistance Poor wear resistance Allergic reaction in surrounding tissue Stress-shielding effect	Bone plates, bone screws and pins, wires, etc	Bowen et al. (2016)
	Co–Cr alloys	Superior in terms of resistance to corrosion, fatigue and wear High strength Long-term biocompatibility	Expensive Quite difficult to machine Stress-shielding effect High modulus Biological toxicity due to Co, Cr and Ni ions release	Shorter term implants—bone plates and wires, total hip replacements (THR)—stem or hard-on-hard bearing system	Bowen et al. (2016)
	Ti alloys	Excellent resistance to corrosion Lower modulus Stronger than stainless steels Light weight Biocompatible	Poor wear resistance Poor bending ductility Expensive	Fracture fixation plates, fasteners, nails, rods, screws and wires, femoral hip stems, total joint replacement (TJR) arthroplasty-hips and knees	Venezuela and Dargusch (2019)