Analysis of tribochemical surface degradation of experimental titanium alloys

Abstract

The use of dental implants in oral rehabilitation stands out for being a versatile, safe and predictable treatment, with titanium as the most used material due to its satisfactory biological, mechanical and chemical properties. Likewise, osseointegration is an extremely important process for bone versus implant surface correlation and is derived from the oxide film formed when Ti comes in contact with air or physiological fluids. Several treatments can be applied to the surface of dental implants (acid, chemical or sandblasting). In this study, the chemical and tribochemical behavior of experimental titanium alloys without and with modification by different layers of chitosan will be analyzed. The specimens used will be made in the form of discs and polished until mirroring and divided according to the groups: as a function of mastication (M); as a function of brushing (E) in three different electrolytes: deionized water (A), fluoride-free toothpaste (F) and fluoride toothpaste (SF). The surface roughness and hardness will be evaluated to characterize each experimental alloy. The electrochemical tests will be performed in open circuit potential and anodic polarization in potential values ranging from -500mV to 2000mV, with a scan rate of 2 mVs-1 (n=5). Complementary analyzes will be performed on the surface of a sample of each experimental titanium alloy by means of scanning electron microscopy (SEM). Tribochemical tests (n=5) will be performed in the alternative linear slip configuration, in the presence of saline solution, in contact with alumina. The normal load to be used will be 10 N, at open circuit potential. For the brushed specimens, the procedures will be performed using a linear brushing machine with a soft bristle brush, for 244 hours with a load of 200N. Scanning electron microscopy (SEM), X-ray diffraction (XRD) and atomic force microscopy (AFM) will also be used. The data will be analyzed by the tests of homogeneity and, if the sample presents a normal distribution, parametric tests will be used, otherwise they will be non-parametric tests. (AU)