The effect of eo and steam sterilization on the mechanical and electrochemical properties of titanium grade 4

Currently, various modifications to surfaces are made more and more frequently in order to improve implants' haemocompatibility. The main criterion determining the applicability of the respective surface-modification method is obtaining a product featuring suitable functional properties. These properties depend to a great extent on the corrosion resistance in the environment of human blood. Subject-matter literature does not devote much attention to the sterilisation process for titanium and cpTi alloys with surface modifications. A problem that still remains unsolved is the selection of a proper test showing the full characteristics of their behaviour contact with a blood environment during the time that the implant is used. Therefore, the authors of this study made an attempt to evaluate the impact of medical sterilisation methods, i.e., the ethylene oxide anodic oxide and SiO₂ layer, by means of the sol-gel method. The efficiency of the suggested technology for oxide layer application was evaluated on the basis of mechanical and electrochemical tests. Sterilisation in ethylene oxide and steam had a favourable influence on the electrochemical and mechanical properties of cpTi, irrespective of the method of surface preparation. In order to simulate real conditions, the tests were performed in artificial plasma at a temperature of T = 37 ± 1 °C and pH = 7.0 ± 0.2. The results proved the diversification of electrochemical properties of the oxide layers, depending on the technological parameters of its application. The suggestion of proper variants of the surface modification with the application of electrochemical and chemical methods is of long-range importance and will contribute to the development of technological conditions with specific parameters for the creation of oxide layers on metallic implants made of cpTi.