Experimental Study of Reparative Osteogenesy of Bone Defects Filled with Calcium-Phosphate Materials and with Polymeric Composite Biomaterial

The problem of replacing the defects of the jaw bones is still far from the final solution, since there is no universal material for osteoplasty at present. There is a problem of the search for synthetic materials for the effective recovery of the lost bone after teeth extraction and processes of atrophy of the jaws bone structures, the need to replacement bone defects of various sizes without sufficiently traumatic use of the patient's own bone tissue. A promising area of research is the development and study of the effect of alloplastic biomaterials on the basis of calcium-phosphate components and high-molecular biopolymers on reparative osteogenesis. The purpose of the study was to compare the effectiveness of various osteoplastic calcium-phosphate materials and biopolymer composites for the restoration of lost bone structures in skulls defects. Material and methods. We studied the dynamics of the processes of reparative osteogenesis of bone defects from the parietal part skull in the experimental animals during the planned terms of the study during 6 months (180 days) and 8 months (236 days). We applied such synthetic (alloplastic) materials as: calcium-phosphate material Kergap (Biomin-GT), Collapan and biocompatible mineral-polymer osteoplastic composite based on resorbing polymer (polylactide) and calcium-phosphate component (hydroxyapatite and beta-tricalcium phosphate). Implantation in the skulls defects was performed on experimental rabbits in two experimental groups. The resulting bone defects were filled with calcium-phosphate osteoplastic materials and a biopolymer composite. In control defects, healing was carried out under a blood clot and without using bone substitutes. Reparative processes in the sites of implantation of the osteoplastic materials were studied in dynamics by light microscopy on histological preparations. Results and discussion. There was a positive dynamics of defects closure when performing implantation of calcium-phosphate and biopolymer materials if compared with control cases. That persisted throughout the period of experimental study indicating the need for using osteoplastic materials for replacing the skull defects. Defects of the parietal part of the skull bone cannot be healed without using osteoplastic biomaterials even after 8 months after intervention. Conclusions. On the basis of the obtained histomorphological data, it can be argued that the characteristic features of osteoregeneration after the replacements of artificial bone defects with a biopolymer composite are the early development of osteoblastoid tissue formation, mature bone tissue regeneration, and faster osteoregeneration process (reparative osteogenesis) not only along the periphery of the defect, but also in its central part with more pronounced differentiation and maturation of structures of newly formed bone tissue in comparison with control and experimental defects in the implantation of Kergap "(Biomin-GT) and "Collapan".