Abstract
Purpose: Additive techniques in dog orthopedics has recently emerged as a valuable approach in fabricating individualized implants for receiver-specific needs. The scaffolds made by 3D printing are used to replaces bones damaged by injuries sustained in accidents, tumour resections and defects resulting from disease, e.g., osteoporosis. In this way, the growth and reconstruction of bone defects structure can be promoted. These implants should have the right properties to ensure the right conditions for bone fusion. It is also important to determine the time of degradation, which is associated with a significant loss of mechanical properties.
Methods: Polylactic acid (PLA) scaffolds with different dimensions were fabricated via fused deposition modeling (FDM) by CABIOMEDE for bone tissue reconstruction in veterinary application. During the research, the mechanical properties and impact of the soaking process in Ringer’s solution for 1, 3, 6 months and steam sterilization for 1, 2, 3 cycles of the scaffolds were assessed. The static compression and three-point bending tests, material wettability, and macro and microscopic observations were carried out.
Results: Compressive test results indicated that PLA scaffolds showed elastic–plastics deformation in longitudinal and transverse directions. The compressive strength of the scaffold in initial state were Rcw = 5–6 MPa in the longitudinal direction and Rcp = 0.33–1 MPa in the transverse direction, depending on size. The flexular strength of the scaffolds were Rg = 348–865 MPa, depending of size. The soaking and steam sterilization process increased the elastic modulus of the material and decreased the flexural strength. Hydrolytic degradation initiated by exposure to Ringer’s solution resulted in a change in structure from amorphous to semicrystalline. This indicates partial dissolution of the amorphous phase and thus, an increase in the percentage of the crystalline phase, which caused the material to become brittle. Progressive degradation resulted in brittle fracture of the material, as can be observed in implants after 6 months of soaking.
Conclusions: The mechanical properties of the PLA scaffolds were close to the properties of cancellous bone. The PLA scaffolds can be anticipated as promising scaffold biomaterials for bone tissue engineering applications by virtue of their bone mimicking porous structure and good mechanical properties.