Healing response to various forms of human demineralized bone matrix in athymic rat cranial defects

Purpose: This study compared the ability of a bone autograft and four distinct forms of human demineralized bone (DBM) to elicit bone repair in a critical size cranial defect in athymic rats. Materials and Methods: Cranial defects were created in athymic rats and then grafted with either an autograft, rat DBM particles in glycerol (rGel), or one of four forms of human DBM: 1) hGel; 2) Putty (DBM fibers in glycerol); 3) Sheet (sheet of DBM fibers); or 4) Flex (DBM fiber sheet with glycerol). Histology, histomorphometry, and radiographic density of the graft sites were evaluated at 8 weeks. Results: Of the grafted defects, 29% to 58% were found to be filled with new bone. The rGel and human forms of DBM stimulated similar amounts of new bone growth in comparison with the autograft-filled defects. The fiber-based grafts produced the largest amounts of new bone. Conclusions: Human DBM in gel, putty and sheet forms were found to perform as well as an autograft in a critical size cranial defect in the athymic rat.