Narrow Results

The release of metals and other elements from dental and orthopedic implants into the tissues has been a matter of numerous studies. However, the conditions that favor such a phenomenon have not been completely understood so far. PIXE microbeam technique has been applied to study the spatial distribution of the elements released from the implants. Subjects of interest have been implants made from commercially pure titanium, Ti-6Al-4V alloy and 316 LWM surgical steel. Block sections of five dental implants, as well as tissues surrounding one metal spine plate and two hip prostheses, have been examined. Rabbit bones containing copper inclusions have been taken for microbeam analysis to complete the study about the metal release processes. Samples from the tissues and bone slices have been analyzed using PIXE microbeam setup at National Laboratories of Legnaro, Italy. Traces of the implant metals, including titanium but with the exception of vanadium, were found in the surrounding tissues and maps of their elemental distribution at different distances from the contact surface with implants have been obtained. The origin and the differences of the release rate of the observed metals have been discussed.

In the past two decades the utilization of dental and orthopaedic implants in reconstructive surgery has been spread widely. Most of these implants are inserted in the corrosive environment of the human body for long periods of time. The level of dissolution, release, and transport of metal ions as a result of corrosion of these materials are not fully known at present. We report the results of application of micro ion beam PIXE spectroscopy to detect release of titanium from titanium and titanium alloy implants inserted in the tibiae of rabbits for three months. It was found that titanium ions could be detected in the surrounding tissues, with high precision, as a gradient from the implant surface and in higher amounts in the bone tissue as compared with the soft tissues. It is concluded that application of micro ion beam PIXE spectroscopy for detection of metal ion release, and distribution of the released material around the implants with high special resolution and accuracy may be used to further investigate the mechanism of metal release, and the relation between surface micromorphology and corrosion resistance of the implant materials.