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

Abstract

Titanium and Ti alloys are widely used in several biomedical applications in cluding cardiovascular stents, shoulder, hip replacement and dentistry. Ti and its alloys are preferred biomaterials, due to their mechanical, physical and biological characteris tics. 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 wetta bility alter the cellular response. In this thesis, four different Ti surfaces; polished, sandblasted, laser processed line and mesh structured, were examined from the aspects of material surface characterization, biocompatibility, hemacompatibility, and biofilm formation. All 4 surfaces showed hydrophilic characteristics. However, sandblasted and line structured surfaces are more hydrophilic than polished and mesh structured surfaces. Although higher platelet activation was observed on polished surface, it is shown that all 4 groups are blood compatible in accordance with ISO10993-4. When the adhesion and viability of fibroblasts were examined on the surfaces, no significant difference was observed. Therefore, the difference of biocompatibility on the polished, sandblasted, line and mesh structured surfaces are shown to be insignificant. For the bacterial adhesion, S. aureus bacteria showed higher tendency for polished surface and E. coli bacteria showed higher tendency for the 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.|Keywords : Titanium, Laser Processing, Roughness, Biocompatibility, Hemacompatibility.