Fracture characteristics of PLA synthetic bone scaffolds with different specimen porosities.

Abstract

Estimation of the fracture characteristics of the bone scaffold is an important aspect to consider in designing the porous structure while complying with its biocompatibility. The basic consideration of the related items, such as the bone scaffold design, material selection, and fabrication process, is necessary to estimate the bone scaffold's characteristics accurately. This present study was conducted to investigate the effects of porosity on the synthetic bone scaffold's strength and fracture mechanics. The specimens were made from polylactic acid (PLA) using an additive manufacturing process. Five specimens with different porosities (0% to 60%) were prepared for the test. Porosity was manipulated by adjusting the pore size during the printing process. The compact tensile test was performed using a tensile testing machine at a controlled rate of 1 mm/min. Various fracture parameters were determined based on force-displacement curves. 30% porosity was found to be the highest critical stress intensity factor, KIC of 0.846±0.069 MPa*m1/2, tip opening displacement, 0.99±0.19 mm, and total fracture energy 2.12±0.34 kJ/m2 after 0 % specimen. For each increment in the porosity, on average 53% reduction of mechanical properties happened. In conclusion, optimising printing settings and material properties with the proper pore design enhances the fracture resistance of printed bone scaffolds, which helps develop effective and reliable bone scaffold structures.