Evaluation of the effect of leukocyte and platelet rich fibrin on wound healing of palatal donor sites after free gingival grafting procedures

Free gingival grafting (FGG) is one of the most common surgical procedures used to increase width of attached gingiva. Hard palate has been the primary source of donor tissue in FGG procedures and most of the documented postoperative complications are associated with the donor site. The palatal donor sites heal with secondary intention so delay in wound healing, bleeding time prolongation and severe pain are common problems with these operations. Leukocyte and platelet rich fibrin (L-PRF), containing high concentrations of autologous growth factors has been thought to accelerate soft tissue healing. In the literature there are only a few case reports associated with using of L-PRF as a membrane to cover the donor site. The aim of this study was to evaluate the efficacy of L-PRF membrane application to to the palatal donor site on wound healing, hemostasis and pain control after free gingival graft harvesting. Twenty-six adult volunteer patients with insufficient attached gingiva were included in this study. The patients to be included in the study were treated with FGG procedure in order to improve inadequate attached gingiva and FGG was harvested from the palatal mucosa. Patients were randomly assigned (13 per group) to the experimental or control groups. In the experimental group, L- PRF membrane was applied and sutured to the donor sites whereas in the control group donor sites were allowed to heal with secondary intention in a conventional way without L-PRF membrane after harvesting of FGG. Patients were observed at 1th, 3rd, 5th, 7th days and 2nd, 3rd, 4th, 5th and 6th weeks postoperatively. Complications such as pain, burning sensation, hemorrhage were evaluated and recorded. Wound healing was assessed visually and also photometrically by digital image analysis. Palatinal pain and burning sensation levels were statistically significantly lower in the experimental group than in the control group during postoperative two weeks (p<0,001). Postoperative hemorrhage in the donor site was significantly lower in the experimental group at 1. and 3. days (p<0,001). Color match of the donor site with the surrounding normal tissue was significantly higher in the experimental group at 1., 3. and 6. weeks postoperatively (p<0,001). The clinical healing index scores obtained according to the macroscopically evaluation of wound healing were significantly higher in the experimental group at 3rd and 4th weeks postoperatively (p<0,001). According to the photometric evaluations, donor site wound surface area decreased significantly with time in the experimental and control groups. Wound surface area reduction from baseline was significantly higher in the experimental group at 3rd day and 1st, 2nd, 3rd, 4th weeks postoperatively (p<0,001). Based on the results of this study; L-PRF provided additional clinical benefits in the SDG procedures by accelerating wound healing at the palatal donor site, reducing postoperative hemorrhage and pain levels. The application of L-PRF membrane may be an efficacious approach to protect the raw oral mucosal wound areas by reducing healing time and postoperative patient discomfort. Key Words: Free gingival graft, leukocyte and platelet rich fibrin, wound healing, membrane, complications.