X. S. Yang, L. Salvati, DePuy Orthopaedics, Inc., Warsaw, IN
Ti6Al4V surface mineralization in rat bone marrow cell culture system was investigated in 3 sample types: 1. polished, 2. grit blasted with mixed Al2O3+SiO2 beads and 3. grit blasted + chemical etched. With SEM, we found that during cell culture, granular minerals precipitated from the culture media under biochemical and chemical functions. Compared with the polished surface, the granular minerals on the grit blasted surface were much less. It shows that grit blasted surface had bad adhesion with minerals. This phenomenon may be caused by the existence of the embedded grit-blasting material in the surface. Since chemical etching removed a certain amount of embedded material in the surface, the adhesion between the minerals and Ti surface was restored after etching. As a result, we observed massive granular minerals on the grit blasted + etched surface.
Summary: Grit blasting is a commom method to roughen a medical device surface. In this paper, we discuss that the embedded grit blasting material in the surface will affect the surface mineralization. When we use silica beads for grit blasting, the silica residue in the surface can reduce the surface adhesion to minerals.
