The effect of titanium surface topography on biocompatibility, hemocompatibility, and bacterial behavior

Titanium and Ti alloys are widely used in several biomedical applications including cardiovascular stents, shoulder, hip replacement and dentistry. Ti and its alloys are preferred biomaterials, due to their mechanical, physical and biological characteristics. Ti is a biocompatible material with high corrosion resistance and several methods are used to process the material in addition to various alloying options. Although, Ti is biocompatible by its nature, cell- material interactions can be improved by surface modification. It is known from the literature that the interactions between material surface and cells, bacteria and proteins are affected by the surface topography. The characteristics of the surface; topography, roughness, surface free energy and wettability alter the cellular response. In this thesis, four different Ti surfaces; polished, sandblasted, line and mesh structured surfaces which were processed with laser, were examined from the aspects of material surface characterization, biocompatibility, hemacompatibility, and biofilm formation. Polished, sandblasted, line and mesh structured surfaces showed hydrophilic characteristics. However, sandblasted and line structured surfaces as they represent higher roughness on the surface, are more hydrophilic than polished and mesh structured surfaces. From the aspect of hemacompatibility, it is shown that all 4 groups are blood compatible in accordance with ISO10993-4. Nonetheless, the platelet activation is shown to be higher on the polished surfaces. When the adhesion and viability of fibroblasts were examined on the surfaces, no significant difference was observed. Abundant number of cells were observed on each of the surfaces. Therefore, the difference of biocompatibility on the polished, sandblasted, line and mesh structured surfaces are shown to be insignificant. For the bacterial adhesion, gram positive S. aureus bacteria showed higher tendency for polished surface and gram negative E. coli bacteria show higher tendency for the rough surfaces line structured, sandblasted and mesh structured specimens in descending order. In this thesis, it is shown that by changing surface topography physically, cellular response to the material can be altered.