Influence of processing parameters on mechanical properties of a 3D-printed trabecular bone microstructure.

Natural bone microstructure has shown to be the most efficient choice for the bone scaffold design. However, there are several process parameters involved in the generation of a microCT-based 3D-printed (3DP) bone. In this study, the effect of selected parameters on the reproducibility of mechanical properties of a 3DP trabecular bone structure is investigated. MicroCT images of a distal radial sample were used to reconstruct a 3D ROI of trabecular bone. Nine tensile tests on bulk material and 54 compression tests on 8.2 mm cubic samples were performed (9 cases × 6 specimens/case). The effect of input-image resolution, STL mesh decimation, boundary condition, support material, and repetition parameters on the weight, elastic modulus, and strength were studied. The elastic modulus and the strength of bulk material showed consistent results (CV% = 9 and 6%, respectively). The weight, elastic modulus, and strength of the cubic samples showed small intragroup variation (average CV% = 1.2, 9, and 5.5%, respectively). All studied parameters had a significant effect on the outcome variables with less effect on the weight. Utmost care to every step of the 3DP process and involved parameters is required to be able to reach the desired mechanical properties in the final printed specimen. © 2019 The Authors. Journal of Biomedical Materials Research Part B: Applied Biomaterials published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:38-47, 2020.