Nano approach at regeneration of experimental periodontal intraosseous defect: X-RAY micro tomoghrapic, histologic and histomorphometric

Aim: The repair of alveolar bone defects caused by trauma, periodontal diseases and inflammation is still a challenge for both researchers and clinicians. Although there are many attempts to regenerate bone based on different graft material and scaffolds, the results are still unsatisfactory. This study aims to clarify whether it could be efficient to reconstruct the three-walled bone defects by nanocrystalin hydroxyapatite graft reinforced with hexagonal boron nitride. Material and Methods: The bilaterally intrabony three-wall periodontal defects were prepared mesially at both maxillary first molar as described previously. Thereafter, defects were filled with the constructs in split mouth design. Each time interval 12 rats (test:6 ; control:6) were sacrificed by injection of high dose of anaesthetics. Histological and histomorphometric analysis were made to evaluate the new bone formation, amount of non resorbed graft material and epithelial attachment level 4 and 12 weeks after transplantation. Micro-CT was also used to estimate the bone healing through three-dimensional reconstruction and the bone density analysis. Results: Hematoxylin - eosin staining and microcomputed tomography showed that at 4 and 12 weeks, test graft material produced a similar result compared to normal bone measurement and there were no statistically significant differences. Control group compared to normal bone measurement demonstrated a significantly reduced bone volume and trabecular number as well as thinner trabeculae in osseous defects. Conclusion: Our results suggest that the strategy of combing NcHA with hBN is effective in the repair of three-walled bone defects and the NcHA bone graft in combination with hBN demonstrated clinical advantages beyond that achieved by the NcHA alone. That's way its clinical application is promising.