Using of Collagen Matrix for Maxillary Tuberosity Donor Area Preservation

An interventional prospective randomised clinical trial (RCT) in parallel groups is planned. The sample size was 30 patients who will be randomly divided into two groups based on the surgical procedure. The first group is the healing of the donor zone after SCTG harvesting without filling the wound with collagen matrix. The second group is the wound defect closure in the donor area using the collagen matrix "FibroMATRIX" (LLC "Cardioplant", Russia; registration in Russia 20/05/2019 No FSZ 2019/83671). Changes in volumetric parameters of the maxillary tuberosity area after CTG harvesting, severity of pain, postoperative edema, bleeding, analgesic intake and quality of life in the postoperative period will be assessed.

The aim of this study is to perform a comparative analysis of the effectiveness of using a double-layer collagen matrix to preserve the parameters of the donor area in the region of the maxillary tuberosity versus healing of the wound surface without its use. Examination and treatment of patients will be carried out on the basis of the Department of Surgical Dentistry of the E.V. Borovsky Institute of Dentistry of I.M. Sechenov First Moscow State Medical University.

The object of the study will be patients with an inclusion defect on the maxilla or mandible within 1-2 teeth combined with a soft tissue thickness deficiency in the area of dental implants (\< 2 mm) which requires mucosal augmentation operation. All patients will be randomly divided into two groups depending on the surgical procedure. In 1 group (n=15) the donor area will heal by secondary tension, and in 2 group (n=15) the collagen matrix "FibroMATRIX" will be used to close the wound defect in the donor area. The groups will be comparable in terms of gender and age characteristics. The randomisation of patients will be performed at the stage of surgical intervention as follows: after taking a free connective tissue graft and adapting the CTG to the recipient bed, an envelope with a randomly assigned method of donor area closure will be opened.

Patients in both groups will undergo dental implantation according to the standard protocol and healing abutment installation. In both groups of patients, a free connective tissue graft will be taken from the maxillary tuberosity and the autograft will be fixed to the vestibular full-thickness muco-periosteal flap with horizontal U-shaped sutures, followed by wound closure using simple interrupted sutures without tension.

Further, the collagen matrix "FibroMATRIX" (LLC "Cardioplant", Russia; registration in Russia 20/05/2019 No FSZ 2019/83671) will be adapted to the donor area for the patients of the 2 group, the patients of both groups will have to perform suturing of the wound surface using simple interrupted sutures.

In the postoperative period, standard antibacterial and anti-inflammatory therapy should be administered in combination with the use of topical antiseptics for daily care.

Eligibility Criteria:
Inclusion Criteria:

1. Presence of written informed consent of the patient to participate in the study;
2. Age between 18 and 45 years;
3. Included defects on the maxilla or mandible within 1-2 teeth combined with soft tissue thickness deficiency in the area of dental implants (\< 2 mm);
4. Teeth without periodontal pathology, probing depth should not exceed 3 mm across the entire dentoalveolar sulcus;
5. Satisfactory level of oral hygiene;
6. Absence of general diseases in the stage of exacerbation or decompensation

Non-inclusion criteria:

1. Patients who had previous harvesting of CTG from the same donor area;
2. Patients with impacted third molars in the donor area;
3. Presence of concomitant diseases in the stage of exacerbation or decompensation;
4. Patients with oncological diseases, as well as patients who have received radiotherapy and chemotherapy in the last 5 years;
5. Patients with a history of smoking for more than 10 years.

Exclusion Criteria:

1. Patient refusal of further participation in the study;
2. Pregnant and breastfeeding women;
3. Patients with blood coagulation disorders (haemophilia, Willebrand's disease, intake of anticoagulants);
4. Patients with diseases that impair soft tissue healing (insulin-dependent diabetes mellitus).