Investigation of an organic delivery system for demineralized bone matrix in a delayed-healing cranial defect model

The osteogenic potential of demineralized bone matrix (DBM) has been demonstrated in multiple animal models and clinical applications. A particulate form of DBM is generally used to fill defects because it is easily packed into a defect site without operative planning or shaping. One potential disadvantage in the use of a particulate is the migration of particles from the defect site. To stem this, glycerol was added to DBM to improve handling properties. A study was undertaken to compare two forms of DBM with glycerol, with DBM particulate and autograft in a bony defect site. The model chosen consisted of bilateral 8-mm trephine defects created in the parietal skull of 40 rabbits. Animals were sacrificed at 2 and 8 weeks. Results demonstrated both cartilage and bone induction with the three forms of DBM, with 75-90% of the linear width of the defect filled with new bone by 2 weeks. This was similar to the autograft (86%) and significantly greater than the unfilled defects (26%) at 2 weeks. The addition of glycerol to the DBM did not affect the inductive capacity, and produced a response similar to that of DBM particulate alone or autogenous bone.