Initial Adhesion of Porphyromonas gingivalis on Thin Alumina-coated Titanium

Abstract

This study was designed to evaluate the initial adherence (during the first hour) of Porphyromonas gingivalis (P.g.) as well as the surface characterization of alumina-coated titanium using a physical vapor deposition technique in order to reduce the adherence of bacteria to titanium implants. The coatings were defect-free films approximately 2 μm thick that were strongly adhered to the titanium substrate and were identified as αalumina. The contact angle to water was 63 degrees (SD: 5 degrees), which was almost equal to that of titanium. The zeta potential at pH 7.0 was 22.4 mV (SD: 3.2 mV), indicating positively charged at around pH 7. The amount of initial adhesion of P.g. was remarkably decreased on alumina-coated surfaces compared to polished titanium. The adherence of P.g. was considered to be related to the surface electrical charge of the materials.These results suggested that a thin alumina coating on titanium is a promising method for reducing the initial adhesion of oral bacteria.