The goal of this clinical trial is to learn if ridge preservation methods with dense polytetrafluoroethylene membranes, with d-PTFE membranes and platelet-rich plasma, and with free gingival grafts can reduce vertical resorption of the post-extraction socket walls.

Researchers compared each experimental group to a control group (unassisted socket healing). Participants were randomly allocated to one of the four groups.

Cone-beam computed tomography was performed after the procedure and 3 months post-operatively to evaluate the vertical socket wall resorption.

Inclusion Criteria:

1. Patients in the age group 18-65 years;
2. Patients in good general condition;
3. Patients requiring extraction of premolars or molars;
4. Patients in whom restoration of the missing tooth with a dental implant and/or prosthetic construction is planned;
5. Signed informed consent to participate in the study.

Exclusion Criteria:

1. Patients with contraindications for general surgical treatment:

   • patients with uncontrolled arterial hypertension;
   • patients with uncontrolled metabolic diseases;
   • patients with AMI in the last 6 months;
   • patients on hemodialysis treatment;
   • patients who underwent chemotherapy and/or radiotherapy in the last year;
   • patients on immunosuppressive therapy;
   • patients on anti-resorptive and anti-angiogenic therapy;
   • patients with concomitant acute diseases at the time of the study;
   • patients with proven psychiatric diseases;
   • pregnancy.

2. There are local contraindications:

   • insufficient volume of bone after the extraction to carry out RP;
   • acute inflammatory disease or tumor process in the area;

3. Lack of informed consent.

4. Lack of patient motivation for the treatment.

It has not been approved by the Research Ethics Committee