In vitro and in vivo biocompatibility testing of Ti-6Al-7Nb alloy with and without plasma-sprayed hydroxyapatite coating

The Ti-6Al-7Nb alloy has been recently developed for biomedical use, particularly for orthopedics and dental applications. Osteosynthesis has been used to analyze biocompatibility and osseoconduction properties. The interaction of the implant with its biological environment, the formation of the implant material/tissue interface, and the long-term success or failure of integration in the human body is strongly connected with the surface properties of the implant device. This study was undertaken to evaluate the processes involved in biological responses of the Ti-6Al-7Nb alloy with and without hydroxyapatite coatings with both in vitro and in vivo tests. The results were analyzed by scanning electron microscopy (SEM) and energy-dispersive x-ray (EDX) microanalysis. The morphology of the in vitro and in vivo testing results with hydroxyapatite coating was similar to those obtained on the uncoated samples. A mineralized extracellular matrix was formed on all materials. Observation of the interface between the cell layer and substrata showed the presence of calcium and phosphorous-rich globular deposits associated with collagen fibers on all materials in vitro and in vivo. A higher density of these globular deposits was observed in all samples. (C) 2001 John Wiley & Sons, Inc.