Methods: The porous-surfaced Ti-6Al-4V implants were prepared with or without the addition of a very thin film of calcium phosphate through sol-gel coating, and implanted into the tibiae of 16 rabbits. Implanted sites were allowed to heal for 12 weeks, after which specimens were obtained for SEM analysis using the freeze-fracture SEM technique.
Results: SEM micrographs of the sol-gel coated implants recovered by freeze-fracture technique show extensive bone growth from the endosteum along the implant surface. Numerous bone spicules are attached to the implant surface in the medullar region. It can be seen that the CaP layer is well adapted to the metal substrate, that bone is in direct contact with the CaP layer, and that there are numerous osteocytes throughout the bone which has grown into the surface porosity. In the neck regions, the CaP film appeares thicker than elsewhere.
Conclusions: Adding a thin layer of CaP to these implants promotes a more extensive implant-to-bone interface by making the neck regions to become intimately ingrown with bone.