In vitro evaluation of surface modifications on dental implant abutments

Titanium (Ti) and its alloys have been increasingly used in dentistry, due to their high strength, low density, excellent corrosion resistance and lightweight. In dental implants, besides screw success and osteointegration, abutment selection and prevention of peri-implantisis are also important factors that influence the overall success of the treatment. This study is focused on gingival tissue adaptation and titanium abutment surface modifications that are usually overlooked in dental implantation. Surface modification of the titanium alloy discs (Ti6Al4V) was carried out by acid etching and microarc oxidation, and the surfaces were coated by zinc acetate (ZnC2H3O2) to implement antimicrobial properties. Surface roughness was determined by profilometer; zinc acetate coating was analyzed by X-Ray crystallography (XRD); surface morphology was analyzed by scanning electron microscopy (SEM); and surface wettability was measured by contact angle measurement. In vitro cell culture analyses were carried out with human gingival fibroblast (HGF) and periodontal ligament fibroblast (PDLF) cell lines. Cell viability was analysed by MTT and SEM imaging after days 4, 7 and 14. Disk diffusion tests for determination of antimicrobial properties were performed with two different bacterial strains. The maximum surface roughness of the obtained structures was achieved in the micro-arc oxidation process. In cell culture studies, cell adhesion was higher on micro arc-treated surfaces and antimicrobial effect was observed on zinc acetate coated titanium discs. Keywords: Dental implant, dental abutment, acid etching, microarc oxidation, biocompatibility.