Application of micro beam PIXE in biomedical implant research

Abstract

The material composition and surface structure of dental and orthopaedic implants influence the integration in bone, and, at the same time, the release of the constituent elements of the implants into the surrounding tissues. Titanium, titanium alloys (Ti-6Al-4V) and other materials which are considered to be biocompatible materials, release metal ions into the surrounding tissues. This may affect the appropriate biological response of the tissues to the implanted materials. The toxicity of some of the constituent elements of these implants, e.g. vanadium, is a matter of serious concern. In this paper, the experimental data on application of PIXE to biomedical-implant research are presented. Two groups of samples were prepared for PIXE analysis. The first group consisted of the specimens that were retrieved from the tissues around implants in 28 rats. The second group consisted of specimens that were sliced and polished to a thickness of a few 10 µm, while keeping the interface between the implant, cortical bone, bone marrow, and soft tissues intact. The implants of the second group, 10 specimens with between 6 and 20 measurement points on each specimen, were used for specifically obtaining the distribution of the released elements with reference to the implant tissue interface, using ion micro beam. The implantation time ranged from 12 weeks to 52 weeks.