The dissertation is devoted to solving the actual scientific and practical problem of modern dentistry, which is to increase the efficiency of elimination of cystic defects of alveolar processes of the jaws by experimental and clinical substantiation of the use of a bioactive long-acting composite medical glue (MG).
On the basis of State Institution «Institute of Chemistry of High Molecular Compounds of NAS of Ukraine» a long-acting composite on the basis of mesh polyurethane – medical glue (MG) is obtained, which has the ability to polymerize in the bone cavity, taking it and forming an adhesive bond at the boundary of polymer-bone-soft tissue distribution, and gradually dissolve.
The presence of micro- and macroporous structures, interconnected compounds of this material were confirmed by the method of scanning electron microscopy (SEM) (pores size – 231 to 806 microns, mesopores size – 45 to 270 microns) of the bioactive long-acting composite MG, which according to the main characteristics corresponded to the structure of the human spongy bone and promoted increasing area of the direct wide contact of material with bone tissue, diffusion of biological fluids by the “capillary” mesh of interconnected compounds and an adhesion of blood cells to its surface, which creates a potential possibility to optimize the conditions of reparative osteogenesis.
The level of CM biocompatibility was evaluated experimentally in vitro and in vivo. Determining the histotoxicity index (HI = 0.82 ± 0.01) by tissue culture in vitro, we conclude that there is no cytotoxic effect of the samples of the bioactive composite on the cultured cells, which indicates a high level of biocompatibility.
In vivo experiments on laboratory rats at the stage of subcutaneous implantation revealed that the bioactive long-acting composite MG were characterized by the formation of a thin connective tissue capsule in terms of 14-30 days with low level of macrophage-lymphocytic infiltration, which had a positive effect on the processes of revascularization and course of the reparative process in the surrounding tissues.
In the simulated defect of the tibia of the rat within 3-6 months after implantation of the biocomposite sample, as it biodegraded, germination of the newly formed connective tissue and young bone tissue was observed in the microporous structure of the material, which testified to the bioactivity and pro-regenerative abilities of the investigated composition.
According to the prospective analysis, the structure, frequency, character of periapical cystic defects (PCD) of alveolar processes of the jaws with predominant localization near the teeth of the maxilla were studied equally on both sides: in the frontal region – 61.7 % of persons; lateral area – 8.5 % of persons; frontal and lateral areas of the mandible: 19.1 % and 10.6 %, respectively.
The vast majority of patients in both groups had complaints of swelling in the area of the alveolar process of the jaw and a slow increase in size, discoloration and displacement of the causal teeth, slight dull aching pain that periodically occurred in this area (3.1 ± 1.1 points per VDS).
There was a tendency for faster reduction of postoperative inflammatory events in patients of the main group: on 5-th day, 10 (62.5 %) patients had no edema and hyperemia, whereas in most of the comparison group 22 (71.0 %) edema was maintained (the difference was statistically significant (p < 0.05) and decreased significantly on 7-th day.
The structure of the newly formed bone regenerate changed over time and acquired radiological features with a characteristic trabecular structure, the radiological density of the regenerate on the Hounsfield scale increased.
At month 12, the mean value of the density in the comparison group was 366.4 ± 44.4 Hounsfield units (HU), and for the main group the mean was higher (p = 0.001) – 460.8 ± 127.6 HU.
The process of resorption of the bioactive composite in the defect filled with it occurred in parallel with bone formation, which provided a tight contact of the adhesive composition with the bone and the postoperative stability of the teeth, the biocomposite prevented the mucous ingrowth of the mucous membrane into the cavity of the postoperative bone defect and the recession of the ash margin.
Filling of the PCD of alveolar processes of jaws by the bioactive composite of prolonged action MG is substantiated and statistically significantly improved efficiency of its elimination.
Keywords: bone defect, alveolar process, bioactive composite, reparative osteogenesis.
