Manufacturing of a metallic 3D framework coated with a bioglass matrix for implant applications

Abstract

In a new approach combining additive manufacturing with bioceramics, a metallic 3D porous structure coated with bioactive glass was produced for possible use in orthopedic implants. This approach aims to combine high mechanical properties of the metallic structure with enhanced biological activity. 316L stainless steel (316L-SS) lattice structures were fabricated using selective laser melting. Despite its good mechanical properties, 316L-SS lacks the biofunctionality required to achieve long-term implantation. To be successfully used as biomaterial, these porous 3D lattice structures were thus coated by 58S bioglass through a simple impregnation method. The use of a silica layer was evaluated as possible pretreatment to improve bioglass adhesion. The coated parts are then assessed by scanning electron microscopy coupled with energy-dispersive spectrometry to qualify the coating. Porous sample parts pretreated with a silica layer presented a denser coating structure when compared with untreated porous metallic structures. The bioactivity in SBF medium shows the formation of a uniform apatite layer after 7 days of immersion, producing the bioregeneration capability. This latter, combined with the lightweight framework structure provided by 316-SS, will increase the lifetime of this new generation of orthopedic implants.