Table 1.

Major advantages and limitations of various metallic biomaterials [[34], [35], [36], [37], [38], [39], [40], [41], [42]].

Classification	Materials	Benefits	Limitations	Applications
Non-biodegradable metallic materials	316L SS	High tensile strength, toughness, and acceptable biocompatibility.	Low wear and corrosion resistance, high elastic modulus, localized corrosion with pitting, crevices and stress corrosion cracking.	Acetabular cup, bone plates, bone screws, pins, rods, hip nails, wires, total hip replacements, etc.
	Co–Cr alloys	Good corrosion, fatigue and wear resistance, and high mechanical strength.	High elastic modulus, toxicity due to release of Co, Cr, and Ni ions.	Short term implants, bone plates and wires, orthodontic wire, femoral stems, total joint replacements, etc.
	Ti alloys	Very good biocompatibility, tensile strength and corrosion resistance, lightweight, and MRI compatible.	Expensive, poor wear resistance and fatigue strength.	Joint replacements, dental implants, cardiovascular implants, prosthetic heart valves, fracture fixation plates, fasteners, nails, rods, screws, and wires.
Biodegradable metallic materials	Mg-based alloys	Good biocompatibility, ability to stimulate new bone formation, biodegradable in a physiological environment, density and elastic modulus close to those of natural bone, and MRI compatible.	High degradation rate, unwanted pH increase in surrounding tissues, inadequate mechanical strength for load-bearing implants, premature loss of mechanical integrity before sufficient bone tissue healing, high H2 gas evolution; Degradation via Mg + 2H2O → Mg(OH)2 + H2.	Bone screws, bone plates, bone pins, cardiovascular stents etc.
	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 orthopedic implants
	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 via 2Zn + 2H2O + O2 → 2Zn(OH)2.	Stents (cardiovascular and coronary stents), orthopedic fixation (sutures, screw, pins and plates).