Design, fabrication and evaluation of a novel 3D-printed temporomandibular joint prosthesis enhanced with elastic layers

Artificial temporomandibular joint (TMJ) replacement is a common intervention for the treatment of advanced temporomandibular joint diseases and ankylosis. The present study addresses the insufficient elasticity of existing artificial TMJs through the development of a composite material by incorporating high-density polyethylene into ultra-high-molecular-weight polyethylene. This was processed using fused deposition modeling 3D-printing technology to produce porous elastic layers with an elastic modulus similar to that of joint discs. An artificial TMJ prosthesis with physiological elasticity was successfully fabricated, applied to the surface of porous Ti-6Al-4V alloy, and validated through mechanical experiments. The results demonstrated that the elastic modulus of the synthetic cartilage exhibits a negative correlation with the number of staggered layers, while no significant relationship was observed between the elastic modulus and the layering cross-angle. The elastic modulus of the cartilage was measured to be 127.5 ± 16.1 MPa, while the maximum compressive strength was found to be 8.0 ± 1.3 MPa. Optimal performance was observed for a staggered layer count of five and a cross-angle of 90°. The bonding strength to the metal mandibular prosthesis was measured to be 2.62 ± 0.98 MPa, and the surface roughness was determined to be 1.6 µm. An elastic artificial temporomandibular joint process prosthesis in this study was successfully designed, fabricated and validated through in vitro experiments, offering valuable insights for future advancements in artificial TMJ design.