Investigating mechanical properties of 3D printed porous titanium scaffolds for bone tissue engineering

Abstract

Objective. Three-dimensional (3D) printed porous titanium scaffolds serve as a bone tissue engineering technology that offers a promising solution for addressing bone defects. The scaffold’s pore structure offers structural support and facilitates the proliferation of bone cells. Therefore, investigating the aperture and pore shape is of crucial for the development of 3D printed porous titanium scaffolds. Methods. Ti6Al4V scaffolds with the specified structure were fabricated using selective laser melting (SLM) technology. The scaffolds comprised fifteen cylindrical models measuring 20 mm in diameter and 20 mm in height. These models featured five scaffold shapes: imitation diamond-60°, imitation diamond-90°, imitation diamond-120°, regular tetrahedron and regular hexahedron. Each of these structural shapes was characterized by three different aperture sizes (400 μm, 600 μm and 800 μm). The porosity and mechanical properties of Ti6Al4V scaffolds were examined. Results. The measured porosity of Ti6Al4V scaffolds varied between 56.50% and 95.28%. The porosity increased with the size of the aperture. The mechanical properties tests revealed that, for identical apertures, the compressive strength and torsional strength were influenced by the configuration of the unit structure. Furthermore, the positive and lateral compressive strength as well as torsional strength of various unit structures exhibited distinct advantages and disadvantages. Within a uniform unit structure shape, the compressive strength and torsional strength were found to be correlated with the size of apertures, indicating that larger apertures result in decreased compressive and torsional strength. Conclusion. The configuration of the aperture and the shape of the pore were identified as significant factors that influenced the compressive strength. The compressive strength of Ti6Al4V scaffolds with various unit structure shapes exhibited both advantages and disadvantages when subjected to positive, lateral, and torsional forces. The enlarged aperture augmented the scaffold’s porosity while diminishing its compressive and torsional strength.