The use of demineralized bone powder in an onlay graft model.

Demineralized bone powder has been shown previously to successfully induce bone formation. The purpose of this study was to use demineralized bone powder in an onlay graft situation using implantable molds. Demineralized bone powder was placed within a mold and rigidly attached to the frontal bones of 30 New Zealand White rabbits by screw fixation. Periosteum was not closed over the mold. A control group had the mold placed without demineralized bone powder used. After 12 weeks of growth, the animals were sacrificed and the frontal bone was analyzed for bone growth using standardized histology and fluorescent microscopy. One hundred percent of the animals (30 of 30) that received demineralized bone powder underwent bone growth in the precise shape of the mold (p < 0.001). There was no new bone development in the control group (n = 8). Placement of larger molds duplicated these results (n = 20) with a 650 percent increase in frontal bone thickness within 12 weeks after placement of demineralized bone powder. This model mimics onlay bone grafting, and perhaps this technique may replace onlay grafting or alloplastic implantation in certain circumstances, avoiding the extra morbidity and donor-site defects associated with bone grafting.