Platelet-Rich Plasma and Platelet-Rich Fibrin as a Regenerative Tool.

Platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) are used as a valuable adjunct in the treatment of maxillofacial rehabilitation. PRP used along with growth hormone helps in bone healing and tissue regeneration in the areas affected by bone and soft tissue-related defects. It aids not only in faster and better healing of the surgically debrided area but also in regeneration of the bone at a faster rate. This review comprises the applications of PRP and PRF and their uses in various procedures. Copyright:

INTRODUCTION

Dr. Arun Garg and Marx pioneered the use of platelet-rich plasma (PRP) in dentistry in 1998. Another variant of platelet concentrate known as platelet-rich fibrin (PRF) was introduced by Dohan, which is vastly used during the treatment in surgical procedures. The macromolecules make up around 10%–15% of the total platelet count.[1] PRP is the first generation of platelet which has been used to promote wound healing in oral surgical procedures, periodontal surgeries, implants, and bone regeneration techniques.[2] It is made up of proteins such as platelet-derived growth factor (PDGF), transforming growth factor (TGF-β), and insulin-like growth factor. PRF which is the second generation of platelets is comprised of growth factors and cytokines, and it is easier to formulate than PRP and it also aids in wound healing.

APPLICATIONS OF PLATELET-RICH PLASMA AND PLATELET-RICH FIBRIN

PRP has been used in surgical procedures such as preprosthetic surgery, periapical surgery, extraction sockets, bone augmentation procedures, and sinus lift procedures.[3] It reduces the risk of infection and recovery time of healing, pain, and inflammation and induces new bone formation at the site of surgery. PRP has been employed in tooth extraction sites, in areas where bone grafts have to be placed for bone regeneration, and in areas where implants are placed for better osseointegration of the bone.[4] The extraction of decayed tooth leads to dry socket and abscess.[5] PRP added in tooth extraction sockets reduces the effect of dry socket and aids in regeneration of the tissue in extracted sockets. It is commonly used in the extraction of impacted molars in patients who are on anticoagulant therapy. PRP has reduced discomfort and swelling postoperatively by simulation with LASER, and the use of fibrin sponge has significantly reduced postoperative pain.[6] The PRP has a lot of growth factors which promotes collagen synthesis by proliferation of fibrinogen with the help of fibrin. It also promotes osteoblast formation which helps in the repair of the wounded site by an increase in vascularity and also helps in the regeneration of bony defects. PRP has been mainly used in the treatment of gingival recession, infrabony defects, and intrabony defects along with a barrier membrane. It has been used in sinus augmentation procedures where graft materials, along with PRP, have been used in the maxillary sinus for regeneration of bone. It is also used in the placement of implants where PRP is used along with graft materials for better osseointegration of implants. Bisphosphonates used in the treatment of bone tumors lead to various complications because of less blood supply and vascularity, which subsequently affect healing of wounds. The treatment of bisphosphonate-related osteonecrosis of the jaw (BRONJ) with drugs results in necrotic bone in an avascular area. It leads to osteonecrosis of the area which results in altered sensation in the mandibular nerve around the affected area, leading to exudates, oral fistula, and further results in mandibular fractures. PRP is used to treat bone infected with BRONJ following conservative surgery to promote healing. The growth factors in PRP promote healing by accelerating epithelial tissues, improve vascularity of tissues, and decrease the rate of inflammation. PRF is composed of fibrin, platelets, and leukocytes. The various cytokines which are involved in PRF preparation are TGF-β, PDGF, vascular endothelial-derived growth factor, insulin growth factor 1, epidermal growth factor, and fibroblast growth factor. The blood sample devoid of anticoagulant is centrifuged. Platelets and leukocytes get incorporated into the fibrin mesh. The first layer after centrifugation consists of acellular platelet-poor plasma. Middle layer consists of PRF; the bottom layer consists of RBC which is discarded. The cytokines released consists of cell migration and proliferation into the fibrin matrix which induces healing of the tissue. The fact that platelets secrete growth factors and active metabolites can have a positive influence in clinical situations requiring rapid healing and tissue regeneration. PRF is used as an adjuvant in diabetic patients after tooth extraction to accelerate wound healing due to their immunocompromised status. Sockets where tooth have been lost due to avulsion but the walls are intact can be regenerated with PRF. PRF along with the graft materials increases the regeneration of bone by binding with fibrin to heal the wounded area. Regeneration and wound healing happen due to migration of cells followed by matrix apposition and remodeling of the bone and tissue in the extracted site. Tooth sockets which are extensively debrided such as impactions and extensively excavated lesions are treated with PRF and graft materials. It is also used in ridge preservation procedures to help in maintaining the ridge width after extraction for the placement of implants. A combination of graft materials that include hydroxyapatite crystals and guided tissue regeneration has been employed to treat periodontal defects. Such lesions are treated with a double-layered membrane of PRF gel and membrane in addition to the graft material to aid in the platelets and leukocytes to deposit in the healing of the lesion site. The proliferation of osteoblasts with PRF aids in phosphorylase extracellular signal-regulated protein kinase to stimulate osteoprotegerin to release osteoclasts which regenerate bone to cover osseous defects. PRF also initiates osteogenic activity of the human pulp cells and also releases growth factors such as TGF and PDGF to help in periodontal regeneration. The PRF is used in treating periapical surgeries by providing a scaffold for the apexification to get completed after the root canal treatment. It helps in regeneration of the pulp tissue. In primary teeth after pulpotomy, PRF is placed along with glass ionomer cement and mineral trioxide aggregate for better and faster regeneration of the pulpal tissue. The regeneration and completion of the root are attributed to the role of osteoprotegerin and alkaline phosphatase which helps the human pulp cells to aid in dentin pulp formation by initiating the odontoblasts and dental pulp cells. The PRF is a matrix which comprises platelets, cytokines, and leukocytes and stem cells. It stimulates gingival fibroblasts, osteoblasts, and periodontal ligament. The interleukin 1 beta, interleukin 4 and 6, and TNF alpha in the PRF help in regulating the immune cells and aid in wound healing. PRF releases various growth factors such as TGF-β and PDGF, which stimulates soft tissue healing and bone formation. PDGF and TGF-β are essential for proliferation, migration, and integrin expression in the wound which activate collagen synthesis.

CONCLUSION

PRP and PRF have generously been employed in oral and maxillofacial procedures to aid in better wound healing and increased success rate in the treatment of surgical procedures in the oral and maxillofacial region.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.