Ultrastructure And Statistical Study On Osteoinductivity Of The Calcium Phosphate

Since the early 90's, Professor Zhang Xingdong in China and few overseas experts simultaneously discovered the new bone formation phenomenon of Calcium phosphate ceramics implanted into the non-osseous sits. The osteoinduction theory has already obtained the widespread approval for year's research work.. As one of bone substitution materials, the Calcium phosphate bioceramics with good bioactivity gets more and more attention nowadays. In order to get further research about the bioactivity and the clinical development of Calcium phosphate bioceramics, we must cany on the work of the osteoinduction mechanism and its comprehensive explanation.At present, the exploration for osteoinductive mechanism and the phenomenon explanation mainly concentrates under the light microscope in the histology and morphologic observation foundation. For the limited resolving power of LM, it is difficulty to make the accurate observation analysis from the histological morphology or differentiation process of new formed tissue. Therefore we need to advance this research to ultrastructure level under the electron, microscope technology.By ultra-slice preparing technology and TEM, we found the bone formation process behaves like this : loose connective tissue grows into the pore - fibroblasts grows and multiplicities along the interface - fibroblasts differentiates into osteoblasts - osteoblasts excretes fibro-collagen and osteoid - Ca/P aggradations on the osteoid - osteoblasts into osteocyte - bone trabecula formation - bone marrow formation. The fibroblasts are the stem cell origin which can differentiate into osteoblastsBy using the TEM, SEM and LM, we can carry on the morphological and ultrastructure observation of new formed tissue in different period, especially in early osteoinductivity period with the new tissue growth into the pore, the formationof osteoblasts, the mineralization of osteoid and the configuration of tissue/material interface. Simultaneously, we are also going to discuss the resource of the MSCs and the differentiation of osteoblasts via the osteoinduction.Meanwhile, in order to reduce the effect from individual difference and to describe the osteoinduction rationally, we take an integrated statistical analysis under LM histological morphology observation. lit shows the amount of bone or bone-like formation was the highest in dog and the lowest in rat. The amount of newly formed bone increased with time. It indicates that the ratio of bone or bone-like tissue formation and the amount of bone formed was significantly related to the animal species and implant periods.