Dose-dependence of and threshold for optimal bone induction by collagenous bone matrix and osteogenin-enriched fraction.

Subcutaneous implantation of demineralized collagenous bone matrix results in local induction of new bone formation. The dose dependence of bone induction was investigated using different amounts of rat demineralized bone matrix (DBM) and also osteogenin-enriched fraction with and without inactive collagenous bone matrix (ICBM). There is a threshold for bone induction; at least 10 mg of DBM is required. There is a dose dependent increase in bone induction between 10 to 25 mg. Exogenous type I collagen was found to be stimulatory to bone induction when suboptimal doses of DBM are employed. The activity of osteogenin-enriched dissociative extract was enhanced by addition of ICBM. These results imply that optimal bone induction requires the combined action of soluble osteogenin-enriched fraction and insoluble collagenous substratum.