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International Journal of Bioprinting 3DP PILF cage for osteoporotic

Figure 4. Two CS-type and P-type forms were designed for implant between L3 and L4 spine body. Top right part shows the dimension of cage, that is,
25 mm in length, 16 mm in width, and 16.2 mm/12 mm in anterior/posterior height. Bottom right part shows the solid and mesh models of CS-type and
P-type cages.

lattice structure was found to stick together after printing A B
because the hole size within the unit lattice was smaller
than 4 mm (a limitation of the metal 3D printer). The cage
3
was fabricated by a metal 3D printer (AM400, Renishaw,
Gloucestershire, UK) using titanium alloy powder
(Ti6Al4V powder with average grain size of 30 μm)
[20]
(Figure 5A). The 3D printing machine was operated with
a laser power of 400 W, a scanning rate of 0.6 m/s, and an
exposure time of 125 s. Completed cages were acid-etched
to remove residual sandblast particles and then cleaned
[20]
using ultrasonic oscillations (Figure 5A) .
C D
Static compressive, compressive-shear, and torsion
tests conformity with the ASTM F2077-14 standard
were performed to evaluate the CS-type cage mechanical
resistance and judge whether compliance with FDA-
recommended values was attained. The superior and
inferior of each three AM cages were clamped using the
specific jigs on the material test machine according to the
ASTM F2077 for all test groups.
For the static compression/compressive-shear tests,
a 500 N preload was applied and a crosshead speed of
6 mm/min was applied until achieving ultimate strength, Figure 5. (A) 3D-printed CS-type cage. (B-D) The clamping device
that is, cage cracked/fractured or force decreased to below of in vitro tests under compression, compression-shear and torsion,
20% of the maximum load (UH-F500 KNI, Shimadzu respectively.

Volume 9 Issue 3 (2023) 415 https://doi.org/10.18063/ijb.697