Evaluation of Selective Laser Melted Ti6Al4V/ST316L Composite and Selective Laser Sintered Polyamide 12 Implants for Orthopedic Applications: Finite Element Analysis, Physical and Mechanical Characterization, in Vitro and in Vivo Biocompatibility

Abstract

This study examined the compatibility of an orthopedic implant made from polyamide 12 sintering, coupled with a composite made from Ti6Al4V/ST316L laser fusion, both in vitro and in vivo. SLM 3D printing was used to construct the composite implant of Ti6Al4V/ST316L, while SLS 3D printing was used for the polyamide 12 implant. SEM analysis, X-ray diffraction analysis, and energy dispersive spectroscopy (EDS) were used to characterize the fabricated implants. Mechanical properties of the implants were evaluated using a universal testing machine. Using finite element modeling, von Mises stresses within implants and human bones could be examined. It involved increasing the cell count and implanting MC3T3-E1 preosteoclasts on implants for a week. Biocompatibility was determined using an AlamarBlue® fluorescence test. After six weeks of implantation, rabbit femurs were stained with Hematoxylin and Eosin to determine in vivo biocompatibility of the implant. Based on the findings, both the polyamide 12 implant and the Ti6Al4V/ST316L composite SLM-3D printed by SLS-3D printing were biocompatible. Finite element analysis revealed that the maximum Von Misses stress was within acceptable limits.