ОРТОДОНТИЯНИНГ ДОЛЗАРБ МАСАЛАЛАРИ» НОМЛИ ҲАЛҚАРО ИЛМИЙ-АМАЛИЙ КОНФЕРЕНЦИЯНИНГ МАТЕРАЛЛАР ТЎПЛАМИ

Аннотация

There is no absolute scientific consensus on the role of the KG, a growing number of clinical trials confirm the idea that the KG strip around the dental implant with a thickness of at least 2 mm can contribute to a healthy condition and a favorable long-term prognosis of implantation. If there is a minimal KG area, the installation of implants can lead to an even greater reduction or complete elimination of it. Its absence leads to excessive mobility of soft tissues around implants, the formation of pockets, gingiva hyperplasia, promotes the formation of fistulas, reduces the resistance to infection, makes it difficult to conduct independent oral hygiene. In addition, non-keratinized tissues are more easily injured. The analysis of scientific studies and clinical cases necessitates the development of less invasive methods for increasing the width of the KD. 123 The aim of the study was to analyze the data of scientific literature and clinical studies devoted to the study of methods for increasing the width of the KG in the implantation zone. Materials and methods. We have studied and analyzed scientific articles, studies and clinical cases that reveal the significance of KG and the effectiveness of various methods of soft tissue augmentation around dental implants in the rehabilitation of patients with dentition defects. Results and discussion. Soft tissue surgery to increase the thickness and width of the KG zone can be performed before the implant is installed, before the implant is opened and at the stage of the actual implant opening. The choice of the time of plastic surgery depends on the specific clinical situation and significantly increases the duration of treatment. The results of plastic surgery may not always be successful, there are often cases of graft rejection, aesthetically unsatisfactory healing, the appearance of a dividing border, the formation of rough scars, etc. According to D.Cardaropoli and P.Casentini (2017), an autologous epithelial- connective tissue graft from the palate is the most effective method of reconstruction of KG. The palate as a donor site has obvious disadvantages, although the patient's discomfort can be reduced by protecting the donor site with a thermoformed plate. Collagen matrices open up prospects for the reconstruction of KG. Unlike autologous tissue, the presence of a strip of keratinized tissue, no matter how insignificant it may be, seems to be important to guarantee the success of the procedure. The biological mechanism of the collagen matrix, apparently, acts by maintaining the space available for the migration of epithelial cells from the surrounding KG. Preliminary results with collagen matrices are promising; however, it is not yet possible to say that these biomaterials can completely replace autologous tissues [1, 3, 5]. According to E.Cohen (2011) autografts with a 0.5-0.75 mm thickness are considered thin and medium, and can be used to increase the KG zone, as well as provide a good aesthetic result. Thin-layer grafts are subject to minimal shrinkage, as they consist of a small number of elastic fibers. But secondary shrinkage in such grafts is more pronounced and averages 25-45% [2, 4]. Muco-periosteal grafts have a thickness of 1.25-2.0 mm. Their use can lead to an unsatisfactory aesthetic result, the result may resemble a "patch". This is due to the fact that a graft taken from a certain area duplicates the phenotype of a certain tissue even after transplantation. Therefore, the graft after transplantation often resembles a fragment of the sky, from where the tissue is mainly taken, does not match the neighboring tissues in color and looks lighter, and the texture may even resemble the relief of a hard sky. Such thick grafts are subject to significant primary shrinkage due to the content of a large number of elastic fibers, but there is practically no secondary shrinkage. The thickness of the graft also affects the increase in the period of revascularization, which delays the healing process of the surgical wound and the engraftment of the graft itself [6]. The most common complications of free gingival autotransplantation are the removal of a smaller graft, its partial perforation, insufficient fixation to the recipient zone, necrosis. The causes of complete or partial necrosis of the graft are too large graft thickness, not tight fit to the recipient zone, insufficient fixation of 124 the graft, incorrect positioning of the graft, violation of blood supply in the recipient zone of various genesis. In order to avoid necrosis, it is recommended to use a gingival graft thinner in thickness in the teeth area and thicker in the implantation area. This is due to the fact that in a larger graft, the microvascular bed is better preserved, which is able to be involved in the blood supply faster, but the primary stage of diffusion through the blood clot is more complicated. A thicker free gingival autograft can be obtained on the palate in the zone fro