ELID (Electrolytic In-Process Dressing) grinding for surface modification of titanium alloy and its effects

In this study, the effects of a surface modified layer formed by ELID (Electrolytic In-Process Dressing) grinding on chemical properties and biocompatibility were examined. An applicability of ELID grinding to create a high bone compatible surface was also discussed. Three types of specimens, which were processed with different surface finishing methods were prepared. These surfaces were then characterized by electrochemical corrosion tests and biocompatibility tests in in-vitro. The surface finished by ELID grinding showed higher biocompatibility and corrosion resistance compared to that of the polished surface. This was because formation of a thick and stable surface-modified oxide layer on the ELID ground surfaces, prevented corrosion reaction. The ELID ground surfaces had high biocompatibility with lower cytotoxic reaction. The ground surfaces by ELID grinding using a NaOH-based grinding fluid showed bio-activeness ; the surface were covered by hydroxyapatite after soaking in simulated body fluid (SBF) for seven days.