ABSTRACT
Low load-bearing applications like filling of holes after cleaning cysts or other defects that are still essentially surrounded by bone, mastoid fillings, replacement of bony walls like portions of the skull, paranasal sinuses, osseous walls of the external meatus, reconstruction of the ossicular chain. Mature lamellar bone in close contact to the alumina surface without visible soft tissue interlayer is seen within two to four months after implantation. Cancellous bone implantation sites as the trochanter or the epiphysis of femur and tibia present difficult biomechanical load patterns which do not allow for an exact prediction of the biomechanical situation along the different surfaces of an implant. Most bone replacements do involve temporary or permanent load bearing situations. Electron microscopic examination revealed that plate-shaped bone mineral crystals were deposited directly onto the surface of the hydroxylapatite ceramic in the very early stage of bonding, with some investigators finding the deposition irregular.
