Evaluation of Bone Repair in the Mandible of Rabbits Using Biphasic Calcium Phosphate Micro-Macroporous Hydroxyapatite Bioceramics and Beta-Tricalcium Phosphate

Objective: To perform a clinical and histological evaluation, characterizing and proving the feasibility of the use of beta tricalcium phosphate (HA/βTCP) bioceramics as a bone defect repair material, comparing it with autogenous bone and blood clot in terms of osteoinductive, conductive, and genic capacities.  Material and Methods: The experiment was based on 3 critical defects in the mandible of 11 New Zealand rabbits. The defects were filled with HA/βTCP bioceramics and autogenous bone, respectively, collected and ground during the development of defects and blood clots. The animals were euthanized after the 90-day experiment and samples were collected for histomorphological examination. To evaluate differences between the groups, a one-way analysis of variance (ANOVA) was performed with Tukey’s post hoc test. An αvalue lower than 0.05 was considered statistically significant.  Results: Microscopy revealed the presence of osteoblasts, osteoclasts, and osteocytes associated or not associated with the presence of mature or immature bone. All the studied materials presented bone neoformation in all cases, with the presence of mature and immature bone. Regarding the presence of HA/βTCP bioceramic residual material, the same was found in 7 of 11 slides.  Conclusion: HA/βTCP bioceramics were shown to be a biocompatible bone substitute, with osteoinductive and osteoconductive characteristics, accelerating the process of new bone formation when compared with autogenous and blood clotted bone, thereby showing promise for bone defect repair with safety and efficacy.