Regenerative osteogenesis at the interface of tissue-osteoplastic material

BACKGROUND: About a half a century ago, the concept of physiological regeneration of bone tissue was developed, which is based on the functioning of basic multicellular units (BMUs). Later it was shown that such an approach can also be used to understand the regularities of reparative regeneration. Bone grafting with the use of gene-activated synthetic replacement materials introduces additional features into the reparative process, consisting in the fact that the material itself becomes a direct participant in the process. Bone graft sequentially undergoes resorption, metabolism, becomes a matrix on the basis of which the basic multicellular units implement the process of regenerative osteogenesis. AIM: to reveal the work of BMUs in a human bone wound during implantation of a gene-activated osteoplastic material from octacalcium phosphate. The material was 16 biopsies obtained during two-stage dental implantation 6 months after bone grafting. METHODS: The results were obtained using microfocal computed tomography, histological and immunohistochemical studies, histomorphometry with statistical processing of the data obtained. RESULTS: According to the results of the study, both in the case of using an ordinary product and when using a gene-activated material based on octacalcium phosphate (OCP), the bone regenerate was represented by a multi-tissue structure formed by bone beams surrounding non-resorbed fragments of bone replacement products. In histomorphometric analysis of gene-activated material, the median area of ​​unresorbed granules was 0,039 mm2 (Q1=0,013 mm2; Q3=0,079 mm2), and the median area of ​​osteoclasts was 67 cells/mm2 (Q1=22 cells/mm2; Q3=235 cells/mm2). In the group using an ordinary product – 0,029 mm2 (Q1=0,009 mm2; Q3=0,068 mm2 and 15 cells/mm2 (Q1=0 cells/mm2; Q3=79 cells/mm2), respectively. CONCLUSION: It has been established that BMUs that are in various phases of functional activity - resorption, reversion, formation and rest can be detected at the gene-activated material-bone interface. The last phase appears only in those cases when the components of the material do not induce osteogenesis.