Comparative Analysis of the Effectiveness of Various Methods of Increasing the Thickness of Soft Tissues During Dental Implantation in the Esthetic Zone of the Maxilla

This is an interventional prospective randomized clinical trial (RCT) in parallel groups. This study is aimed at detecting a difference in the increase in the thickness of soft tissues of at least 0.3 mm between the two groups (the standard deviation [SD] of 0.3 mm and the average value of 1.2 mm was borrowed from an article published by Cairo F et al., 2017). Using SampleSizeCalculator, it was calculated that the number of patients in each group should be 14 (alpha = 0.05; power = 80%). This number was increased by 10%, taking into account possible exceptions from the study. The sample size is 30 patients who will be randomly divided into two groups depending on the surgical intervention used. First group - patients will undergo increasing the thickness of the mucous membrane using free connective tissue graft from tuberosity area of the maxilla or palate. Second group - patients will undergo increasing the thickness of the mucous membrane using collagen matrix "Fibro-Gide" (Geistlich Pharma AG, Bahnhofstrasse 40, 6110 Wolhusen, Switzerland; registration in Russia 19.08.2020 No FSZ-20207/11765). In the postoperative period the value of soft tissue thickness gain, severity of pain syndrome, collateral edema, Doppler flowmetry, probing depth, soft tissue aesthetics, keratinized mucosa width and quality of life will be assessed. In addition, after 3 months simultaneously with installation of gingiva formers biopsy specimens will be sampled with mucotome in the area of the intervention followed by histomorphometric analysis of the obtained biopsies.