An autogenous bone graft and platelet-rich fibrin (PRF) membrane as a treatment strategy for closure of OAF has also been proposed [50]. PRF is a product of centrifuged blood. The biochemical components of PRF are well-known as factors acting synergistically in the healing process. This includes platelet-derived growth factor (PDGF), whose components are the reason why PRF has anti-inflammatory properties. The PRF membrane covers the graft, while the components contained in it have positive impact on its integration. A trapezoidal mucoperiosteal flap is formed in the oral cavity vestibule. The alveolar width of alveolus and the average height of alveolar bone lamina from the side of the oral cavity vestibule and from the side of the palate are measured intraoperatively. The next stage depends on the cavity diameter and involves collection of monocortical bone blocks from the mental protuberance or mandible oblique line. The bone blocks are formed in a way which makes it possible to wedge them in the cavity and tightly close the defect. The graft is stabilized using a bicortical screw or a titanium mini-plate. Bone irregularities are smoothed. The graft and surrounding bone are covered with a PRF membrane. Thereafter, the membrane is tightly sutured without tension the vestibule flap [50].

More recently, triple-layered was introduced by George [51]. This novel technique uses leucocytes-platelet-rich fibrin (L-PRF) membrane concomitantly with the buccal advancement flap and buccal fat pad. The platelet-rich fibrin membrane is placed over the buccal fat pad and completely covered by a buccal advancement flap. The positive feature of the L-PRF membrane is expediting the healing process by producing growth factors and leucocytes.

The use of PRF alone as a clot and a membrane for the closure of OAFs was documented by Assad et al. [52]. They advocated closing OAFs by using PRF individually. PRF was prepared by taking blood samples into glass-coated plastic tubes without anticoagulant. The samples were centrifuged immediately. A fibrin clot was formed in the middle part of the tube. Then, it was separated from other acellular plasma and red blood cells. Thereafter one third of the fibrin was cut off and inserted gently into the OAF. The remaining two thirds of the clot were pressed gently with sterile dry gauze to drive out the fluids and form the membrane. The OAF site was covered with the membrane which was sutured to the gingival margins. PRF can be considered an autologous biomaterial and as well as a membrane. PRF as a membrane and grafting material facilitates formation of mineralized tissue due to osteoconductive and/or osteoinductive properties possibly inherent in PRF.