Bacterial colonisation of porous titanium coatings for orthopaedic implant applications – effect of surface roughness and porosity

Bone ingrowth into and through porous coatings on orthopaedic implants can substantially improve fixation. However, the introduction of pores increases surface roughness and also the risk of bacterial adherence, which can lead to infection (in extreme cases, to death) and complicate implant surgery due to the high risk of revision being required. Improving osseointegration without increasing infection risk is therefore a major challenge in implantology. Staphylococcal adhesion and biofilm formation on Ti surfaces of varying roughness and porosity have been investigated in vitro. Porous pure titanium coatings, obtained by a PM processing route based on the electrophoretic deposition of TiH₂ followed by thermal treatment in vacuum, significantly reduced bacterial colonisation of the surface compared with a state-of-the-art vacuum plasma sprayed coating. Further reduction of biofilm formation could be obtained by additional surface modification.