STATIC OSTEOGENESIS AND DYNAMIC OSTEOGENESIS: THEIR RELEVANCE IN DENTAL BONE IMPLANTS AND BIOMATERIAL OSSEOINTEGRATION

The present report summarizes the results of a series of investigations carried out in our laboratory on intramembranous ossification occurring under normal condition during skeletal organogenesis and osseointegrations of dental implants and biomaterials. No morphological differences were observed between normal and pathological conditions, since the same following sequence of events were found. Inside the embryonic mesenchyme or the connective tissue formed after bleeding, due to surgery, cords of plum cells, displaying the typical osteoblastic structure, differentiate in between the blood capillaries. These osteoblasts appear to be stationary since they do not move, but transform into osteocytes in the same site where they differentiated, thus giving origin to a trabecular woven-bone framework laid down by static osteogenesis (SO). Soon after, typical movable osteoblastic laminae differentiate along the surface of this SO-trabeculae and thicken them with lamellar bone formed by dynamic osteogenesis (DO). SO seems to depend on inductive stimuli and appears to be mechanically independent, whereas DO mainly depend on mechanical strains. Additionally SO-bone is a bad quality bone because of its woven texture and high microporosity, due to the many osteocyte lacunae it contains, whereas DO-bone generally is a lamellar bone and thus mechanically much more resistant.The clinical implication of these findings, as regards the time of load application after prostheses/biomaterials implantation, is discussed.