Zirconium - an alternative implant material in bone?

REBECCA HOERTH; MARÍA ROSA KATUNAR; ANDREA GÓMEZ SÁNCHEZ; SILVIA M. CERÉ; WOLFGANG WAGERMAIER; JOSEFINA BALLARRE

Warnemunde - Rostock

Simposio; 4th International Symposium of Interface Biology of Implants; 2012

Metal implants are frequently used in medical and orthopedic applications in humans. Joint replacements for example are supposed to rest for 10-20 years in the patient?s body and to be integrated in the bone to bear the load that the replaced bone bore before. In the current project we look for alternatives to commonly used titanium implants and we investigate their properties regarding osteoconductivity depending on the metal itself and on the surface treatment. In particular we pay attention on the maturity of the newly grown bone in terms of organization and ultra-structure of the tissue. Needle shaped titanium and zirconium implants that are surface treated by 30 volt anodization in phosphoric acid or not treated at all, have been permanently introduced into the marrow cavity of rat long bones. 8 weeks after implantation there is a continuous small layer of bone, newly laid down on the implant surface, which is already in a relatively mature state. Using polarized light microscopy, back-scattered electron imaging, synchrotron x-ray fluorescence and small angle x-ray scattering techniques we analyze the orientation of the collagen fibers, visualize the mineral content qualitatively, and investigate the thickness and the orientation of the hydroxyapatite crystals. Our results show that the newly formed bone tissue already reaches a high level of organization in both, the mineral phase and the collagen matrix. The orientation of collagen and mineral particles can be described as circumferential to the implant?s surface and the thickness of the mineral particles is within the range of normal mature bone. Regarding the bone properties we conclude that zirconium implants are potential alternatives to prevalently used titanium implants.