Synthesis of bioactive glass coating for titanium surface using the plasma electrolytic oxidation: electrochemical and antimicrobial analysis in a microcosm model

Abstract

Materials that exhibit antimicrobial and osteogenic properties are promising alternatives to improve the biocompatibility of implants. In this perspective, the aim of this study is to synthetize a bioactive glass (Bioglass-45S5®) for the surface treatment of commercially pure titanium discs (cpTi) using the plasma electrolytic oxidation (PEO), and to evaluate its influence on the physical-chemical, electrochemical and antimicrobial properties of cpTi. CpTi discs (10 × 2mm) will be used: machined (control group) and treated with Bioglass-45S5® (experimental group). The topography of the discs will be characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), profilometry and surface free energy. The composition and phases of the oxide layer formed on the surface will be evaluated by means of energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction analysis (XRD). Electrochemical tests will be conducted (open circuit potential, electrochemical impedance spectroscopy and potentiodynamic test) to analyze the corrosive behavior of the cpTi. The effect of treatment on bacterial adhesion and biofilm formation on the surface will be tested using multi-species biofilm model of microcosmos, human saliva will be used as bacterial inoculum. In the quantitative analysis of the microbiological data the pH of the biofilm and the levels and proportions of 40 bacterial species will be evaluated by the checkerboard DNA-DNA hybridization technique. SEM and laser confocal microscopy (live and dead) will be used to visualize the formed biofilm. Quantitative data will be submitted to the most appropriate statistical analysis with 5% significance level. The number of specimens for each test will be determined after the pilot study. (AU)