Heterologous demineralised bone matrix is efficient for the repair of critical-sized rat calvarial defects

Aim. To evaluate the efficacy of heterologous demineralised bone matrix (DBM) for the replacement of bone defects using a critical-sized rat calvarial defect model. Materials and Methods. For the experiments, we used 48 Sprague-Dawley rats (4.5 to 6 months of age). Critical-sized (8 mm diameter) calvarial defect was filled by the bone autograft, heterologous DBM, or comparator product (Geistlich BioOss®) or remained unfilled (negative control). Upon 4 or 12 weeks, rats were euthanised with the subsequent investigation of the defect and adjacent tissues by means of hematoxylin and eosin staining (mineralized tissue area to the defect area ratio) and microcomputed tomography (volume, thickness, and mineral density of the repaired tissue). Results. In our experimental setting, bone autograft was the most efficient in bone repair. Heterologous DBM and comparator product were equally efficient in filling the defect and did not show any statistically significant differences regarding any of the parameters. Microcomputed tomography and routine histological examination demonstrated concordant results. Conclusion. Heterologous DBM is efficient for the repair of critical-sized rat calvarial defects.

Native Bovine Hydroxyapatite Powder, Demineralised Bone Matrix Powder, and Purified Bone Collagen Membranes Are Efficient in Repair of Critical-Sized Rat Calvarial Defects

Here we evaluated the efficacy of bone repair using various native bovine biomaterials (refined hydroxyapatite (HA), demineralised bone matrix (DBM), and purified bone collagen (COLL)) as compared with commercially available bone mineral and bone autografts. We employed a conventional critical-sized (8 mm diameter) rat calvarial defect model (6-month-old male Sprague–Dawley rats, n = 72 in total). The artificial defect was repaired using HA, DBM, COLL, commercially available bone mineral powder, bone calvarial autograft, or remained unfilled (n = 12 animals per group). Rats were euthanised 4 or 12 weeks postimplantation (n = 6 per time point) with the subsequent examination to assess the extent, volume, area, and mineral density of the repaired tissue by means of microcomputed tomography and hematoxylin and eosin staining. Bovine HA and DBM powder exhibited excellent repair capability similar to the autografts and commercially available bone mineral powder while COLL showed higher bone repair rate. We suggest that HA and DBM powder obtained from bovine bone tissue can be equally applied for the repair of bone defects and demonstrate sufficient potential to be implemented into clinical studies.