Implant associated infections are responsible for over 10 % of recorded orthopaedic revision surgeries across the UK, with higher infection rates commonly observed for other endoprostheses such as cranioplasties. To prevent colonization and biofilm formation on implant surfaces, the use of silver coatings has shown positive results in clinical setting due to its synergistic function with conventional antibiotic prophylaxes. Additive manufacturing allows manufacture of entirely new implant geometries such as lattice structures to enhance osseointegration, however this limits the ability to uniformly coat implants. Direct integration of silver into the powder feedstock for selective laser melting (SLM) may allow manufacture of a biomedical alloy with innate, long lasting antimicrobial properties without compromising possible geometries and with no coating process necessary. Feedstock powders of 15–45 micron Grade 5 Ti-64 (Renishaw Plc) and Ag-999 powder (CooksonGold) were characterized using laser particle size analysis, ICP-OES, LECO-ONH, and morphological analysis in SEM. A blend of Ti-64 with 3 wt% Ag-999 powder (Ti-643) was produced by tumble blending, and validated by SEM and EDS. Parameters for manufacture were established using a 17 point design of experiment (DoE) exploring a 2D parameter space of applied laser power and laser scanning speed. Samples were manufactured using a ConceptLaser M2 LaserCusing SLM. Density was assessed by He pycnometry, and cross-sections analysed for defects by optical microscopy. Silver distribution was mapped by micro X-Ray Fluoroscopy (µXRF) and energy-dispersive X-ray spectroscopy (EDS). Optimum parameters were identified and used to manufacture all subsequent samples. Cylindrical Ti-643 samples were manufactured for further physical characterization and bacterial investigation, alongside control Ti-64 samples manufactured using existing optimum parameters. Samples were polished using silicon carbide papers to a 4000-grit surface finish. Contact angle measurements were made by goniometry. Silver elution characteristics were assessed by immersion in water refreshed on a daily basis, and sampled over a 14 day period using ICP-OES. Viability of Introduction
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