Purpose: 3D printing has shown enormous potential for building plastic products, including
bone, organs, and body parts. The technology has progressed from visualization and preoperation
training to the 3D printing of customized body parts and implants. This research
aims to create 3D printed bone structure from plastics and test the mechanical properties
of the cortical and trabecular bone structures if they match the real bone structure strength.
Design/methodology/approach: We used Digital Imaging, and Communications in
Medicine (DICOM) images from Computer Tomography (CT) scans to created external
bone structures. These images' resolution did not allow the creation of fine trabecular bone
structures, so we used 3D modeling software to engineer special 3D void honeycomb
structures (with triangular, square, and hexagonal shapes). Another reason to design
void structures is that the 3D printing of complex shapes without support materials is
problematic. After designing and 3D printing of the 3D bone structures, their mechanical
properties need to be tested.
Findings: 3D bone models, solid (cortical), and void (trabecular) bone structures were
designed, 3D printed, and then tested. Tensile, bending, and compression testing was
performed. Testing the mechanical properties of the honeycomb structures (triangular,
square, and hexagonal) shows that their strength and modulus are higher than those of the
real trabecular bones. The results show that 3D printed honeycomb structures mechanical
properties can match and some cases exceeding the properties of the actual bones
trabecular structures, while the sold structures have lower mechanical properties than the
bone cortical structures.
Research limitations/implications: During the 3D printing experiments, we found
that 3D printers, in general, have low resolution, not enough to print fine trabecular bone
structures. To solve the existing 3D printing technology's insufficient resolution, we later
designed and built an SLA (stereolithography) 3D printer with high printing resolution (10
micrometers). Another limitation we found is the lack of biocompatible materials for 3D
printing of bone structures. Future research work is in progress formulating superior ink/resin
for bone structures 3D printing. Further, clinical trials need to be performed to investigate 3D
printed parts’ influence on the healing of bone structures.
Practical implications: We found that the 3D void (honeycomb) structures will have an
impact not only on building bone structures but also in engineering special structures for
industrial applications that can reduce the weight, time, and the cost of the material, while
still keep sufficient mechanical properties.
Originality/value: Designing and testing 3D printed bone models, solid (cortical), and void
(trabecular) bone structures could replace bones. Design and test special void honeycomb
structures as a replacement for cortical bone structures.
3D-printing for engineering the next generation of artificial trabecular bone structures
