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International Journal of Bioprinting Continuous gradient TPMS bone scaffold

First, a hollow cylindrical space, representing a and exhibits good permeability, meeting the requirements
quarter of the human bone structure, was created. The for bone reconstruction. This research contributes to the
G_4x12 model was generated within this space, as shown evaluation, development, and application of Ti-6Al-4V
in the Boole Model in Figure 18. Next, a Boolean merge porous structures for orthopedic purposes.
operation was performed on the resulting Boole Model to
create an implant that mimics the complete structure of the 6. Conclusion
human bone, as shown in the Bone Model in Figure 18. In this study, we conducted bionic structure optimization
Then, Laplace smoothing method was used to smooth design for bone implants. The TPMS structure was
the joints of the Bone Model, resulting in a smoother optimized through a combination of experiments and
transition and tighter connections, as shown in the Smooth simulations. We thoroughly discussed the parametric
Model in Figure 18. A dense bone region was added to design method, mechanical properties, and permeability
the Smooth Model to obtain a bone implant model ready of the continuously graded TPMS bionic bone structure.
for manufacturing, as shown in the Bone Implants in The key conclusions and findings are as follows:
Figure 18. Finally, the implant was fabricated using a metal
3D printer (L-PBF system CR-PBFM250), and Ti-6Al- (i) Based on the characteristics of bone structure, we
4V was used as the material. The 3D-printed sample in established a linear function C = 0.1954 * z + 0.3124
Figure 18 showcases the physical bone implant obtained and a range of z to represent the gradient change in
through this process. porosity of the continuous gradient TPMS structure.
This study provides essential information for the rational (ii) Under the same porosity change, the mechanical
design of porous orthopedic implants using additive properties of the continuous gradient TPMS structure
manufacturing. To repair necrotic or broken human femur, are significantly affected by the periodic parameter ω.
Figure 19 presents a personalized bone implant design The mechanical properties of the G-type continuous
process using the human femur as an example. The chart gradient porous structure increase initially and then
is simplified, using a model of a specific shape implant. decrease with increasing ω. However, the mechanical
The front-end-designed human bone implant model properties of the P-type continuous gradient porous
possesses mechanical properties that match human bones, structure consistently increase.

Figure 19. Flow chart of design and optimization process of personalized porous bone implant. Abbreviation: CT, computed tomography.

Volume 10 Issue 2 (2024) 327 doi: 10.36922/ijb.2306