Influence of the methods of mechanical processing and sterilization on the structural-and-functional condition of the surface layer of bone samples

The authors presented the results of structural-and-functional analysis of the surface layer of bone tissue samples after their mechanical processing and sterilization. Bone samples of the given height were produced on a precision cutting machine using disc cutters. They were made from cylindrical blanks obtained from the fragments of bovine femoral shaft using hollow cutters. In this case, one of the end surfaces of bone samples was processed with a steel cutting disc with teeth, and the second one - using a disc milling cutter with with diamond-coated cutting edge. The samples obtained were sterilized by different methods: ozone, radiation and combined, based on combined ozone-oxygen exposure at the first stage and radiation exposure - at the second. The elastic-plastic properties (Vickers microhardness index) of the surface layer at the ends of cylindrical bone samples were determined after mechanical and sterilizing physicochemical exposure. Scanning electron microscopy was used when studying the patterns of changes in the structure of sample end surfaces. The advantage of mechanical processing of bone samples using a cutting disc cutter with diamond-coated cutting edge has been established compared to using a circular milling cutter with a cutting edge in the form of teeth. The studying of elastic-plastic characteristics of the surface layer of bone samples in mirovolumes demonstrated that the sterilizing physicochemical exposure to ozone-oxygen mixture, to radiation processing using a flow of fast electrons with radiation absorption doses of 10, 15 and 20 kGy, as well as their combined exposure did not have significant effect on the values of sample microhardness.