Powder Bed Fusion Versus Material Extrusion: A Comparative Case Study on Polyether-Ether-Ketone Cranial Implants

Area of Science:

• Biomaterials Engineering
• Additive Manufacturing
• Medical Device Fabrication

Background:

• Additive Manufacturing (AM) offers diverse technologies for fabricating medical implants.
• Selecting the optimal AM technique for specific applications like cranial implants is challenging.
• Polyether-ether-ketone (PEEK) is a suitable material for cranial implants due to its biocompatibility and mechanical properties.

Purpose of the Study:

• To compare the dimensional accuracy, compression performance, and impact behavior of PEEK cranial implants fabricated by Powder Bed Fusion (PBF) and Fused Filament Fabrication (FFF).
• To evaluate the suitability of PBF and FFF for producing patient-specific cranial implants.
• To understand the failure mechanisms of PEEK implants produced by different AM methods.

Main Methods:

• PEEK cranial implants were manufactured using PBF and FFF techniques.
• Dimensional accuracy was assessed by comparing printed parts to original CAD models.
• Mechanical testing included compression performance and drop tower impact evaluation.
• Failure mechanisms were analyzed post-testing.

Main Results:

• Both PBF and FFF implants exhibited dimensional deviations from the CAD design.
• FFF implants demonstrated superior energy absorption during compression and impact tests compared to PBF implants.
• FFF samples exhibited greater deformability and more consistent failure modes, with localized damage.
• PBF samples showed brittle behavior, leading to catastrophic failure.

Conclusions:

• FFF is a promising AM technique for cranial implants, offering better mechanical performance and energy absorption than PBF.
• The choice between PBF and FFF depends on desired mechanical properties and acceptable post-processing requirements.
• FFF implants may offer improved clinical outcomes due to their enhanced deformation and energy absorption capabilities.