Osteoblast compatibility of 3D printed Co-Cr-Mo alloys with different building direction

Three-dimensional(3D)metal printing is an attractive technique for fabricating biomedical devices.The microstructures and mechanical properties of the fabricated 3D metal printed products show anisotropy because the grains grow along the z-axis direction.However,the effects of different printing directions on the cytocompatibility of the products are unknown.In the present study,cobalt-chromium-molybdenum(Co-Cr-Mo)alloy cylinders were fabricated along the z-axis(vertical)and x-axis(horizontal),respectively,and the effect of build direction on the cytocompatibility was evaluated.The build direction of 3D printed Co-Cr-Mo alloy changed grain anisotropy;however,there was no statistical difference in grain size.The wettability,protein adsorption,cell attachment,and cell proliferation on the disks of vertical and horizontal products were similar to those on cast alloy;they were significantly lower than those of commercially pure titanium and tissue culture polystyrene.The build direction of 3D printed Co-Cr-Mo alloy does not affect osteoblast compatibility.