Comparison of Bone Graft Preparations to Treat a Critical Bone Defect on a Rodent Animal Model.

Although autologous bone grafting is the most widely used treatment for bone defects, the most effective preparation remains unclear. This animal study aimed to compare different autologous bone grafting preparation for the treatment of rat́s calvaria critical bone defect.  122 rats were randomly allocated into three groups: Simulado, Macerated and Chopped. The specimens underwent craniotomies at the top center of their calvarias with a 7mm diameter circumferential cutter drill. The critical bone defect produced was treated or not according to the group the specimen wasallocated. The rats were euthanized at 3, 6 or 12 weeks post-op and its calvarias were analyzed by histomorphometry, bone densitometry, nanocomputed tomography (nCT), and biomechanical tests.  The histomorphometry analysis showed the highest percentage of fulfillment of the critical bone defect in the chopped and macerated group when compared to simulado. The densitometry assessment evidenced higher bone mass at all endpoints analysis (p < 0.05) in the chopped group. The nCT data exhibited an expressive increase of bone in the chopped group when compared with the simulado and macerated groups. The biomechanical tests exhibited highest values of deformation, maximum force, and relative stiffness in the chopped group at any time of euthanasia (p < 0.05).  Our experimental work showed that chopped bone grafting preparation exhibited significant better outcomes than macerated in the treatment of a critical bone defect in rat́s calvaria.