Determine the function of Osseointegration
Osseointegration is also a measure of implant stability, which occurs at two stages- primary and secondary. Primary stability has been found to be essential for obtaining successful secondary stability. Therefore, a feature of osseointegration is the transition of the implant from the primary (physical) stability to secondary (biological) stability. We first need to understand, how to achieve primary stability? It is obtained mainly in the cortical bone compartment by press fitting an implant (attained by placing a slightly oversized implant in a surgically prepared implant bed or osteotomy site). This causes plastic deformation of bone resulting in fissure and microcracks. The blood vessels are also compressed or ruptured, thereby having a zone of avascular necrosis. This avascular bone activates remodeling and with time the avascular bone is replaced by vital bone.
Therefore, primary stability of an implant comes from the mechanical engagement of the implant with bone when it is placed surgically while the secondary stability is through the process of osseointegration and involves bone regeneration and remodeling around the implant