PATHOMORPHOLOGICAL CHANGES IN THE MANDIBLE BONE WITH VARIOUS OSTEOREGENERATION METHODS IN THE EXPERIMENT

The article presents a study of pathomorphological changes in the lower jaw bone in rats undergoing osteoplasty of a
bone defect in an experiment. The study was conducted on male Wistar rats. Three groups of 20 animals were formed.
In the first group, the defect was replaced with bone shavings, in the second – with Kollapan-L material, and in the
third – with Kollapan-L with committed autologous mesenchymal stem cells. In the 3rd group of animals, the presence of young connective tissue rich in cells, vascular proliferation and maturation of connective tissue to coarse scar tissue with lymphohistiocytic infiltration were determined, especially at 30-60 days. The Ki67 proliferation index by day 30 of the experiment in the three groups was distributed as follows: 4.93%, 18.2 and 32.8%, indicating a stimulating effect of mesenchymal stem cells. The obtained data indicate acceleration of physiological regeneration under the influence of mesenchymal stem cells committed in the osteogenic direction. The immunomodulatory effect of stem cells allowed to significantly reduce the percentage of purulent infiltrates in the bone defect. Increased expression of proliferation markers Ki67 and angiogenesis markers CD 36 promotes accelerated bone tissue regeneration.