An Anti-Bacterial Coating in Dental Implant Used in Orthopaedics/ Feasibility Study of Anti-Bacterial Coating in Dental Implant for Orthopaedic Use

Abstract

Bacterial adhesion becomes an important event in the pathogenesis of bacterial infection. Plasma surface modification, with nitrogen layer, to resist bacterial activity has successfully been implemented to dental implants [1]. We hypothesize that same surface modification can be applied to orthopedic and suppress bacterial attachment. This study aims to investigate the feasibility of antibacterial ability of medical grade titanium alloy treated with nitrogen plasma immersion ion implantation (PIII). Surface roughness and depth profile of N-PIII samples are determined by atomic force microscopy and X-ray photoelectron spectroscopy. Since S. aureus is found in orthopedic post-op infection, an overnight culture of this bacterium in 1X108/ml CFU is prepared for colony forming unit counting. In surface roughness measurement, N-PIII modified sample seems to be rougher than the control. The surface morphology is changed after PIII. XPS results reveal the thickness of nitrogen-rich layer ranges from 19.88nm to 99.4nm. Therefore, nitrogen plasma is successfully implanted into the substrate. In CFU counting, the numbers of attached bacteria of N-PIII samples are about 3 folds higher than the control. It therefore suggests N-PIII Ti surface does not have an ability to reduce S. aureus adhesion. It should understand the bacteria in oral are different from S. aureus. Nitrogen plasma treated sample can suppress the adhesion of oral bacteria and salivary protein, but not to that bacterium. Therefore, a concern must be taken if this surface coating is used as antibacterial layer in orthopedic implants. [1] J. Oral Implant Vol.XXIX No.2.2003.