Platelet rich plasma (PRP) has had numerous applications in the medical field all throughout the decades and was first used in Oral Maxillofacial Surgery in 1998. PRP is extracted from blood using an ultracentrifuge. The Red Blood Cells (RBCs) settle to the bottom as the pellet, followed by a buffy coat which consists of White Blood Cells (WBCs) followed by the PRP. However, there are some issues with using PRP. An anticoagulant is required for its preparation. The fibrin network in PRP is loosely packed and is susceptible to RBC contamination. The growth factors released from a PRP clot are not sustained for a long period of time.
Dr. Joseph Choukron first introduced Platelet Rich Fibrin (PRF) in 2000 was found to have better qualities than PRP. PRF is an autologous platelet concentrate/clot free of RBCs and is obtained by using a specific technique of centrifugation. An anticoagulant (bovine thrombin) is not required for obtaining PRF as the biological process of clot formation is enhanced. The growth factors released from PRF is sustained up to 7 days which can enhance the wound healing process.
In PRF, the fibrin polymerises into a highly organised 3-D network which greatly favours cytokine and cellular enmeshment. The PRF clot has higher levels of fibrin, leukocytes and cytokines than PRP.
MedPiper Technologies and Journomed along with the Society of Periodontists and Implantologists of Kerala (SPIK) had conducted a webinar on 30th September, 2021 where the speaker Dr. Mihir Kulkarni discussed the various features and applications of PRF in dentistry. Dr. Mihir Kulkarni is a Periodontist and Implantologist and Assistant Professor at SDM College of Dental Sciences, Dharwad. He is also a fellow at the Indian Society of Implantologists and has published several works on the use of PRF in palatal wound healing.
Platelets are the star-shaped cells that make up the blood along with RBCs, WBCs and serum. Platelets are the key players involved in the wound healing process. Whenever there is an injury to the skin or surfaces, the platelets rush to this spot and initiate the formation of a clot that is mainly fibrin. Cytokines and cells interact within the fibrin network to facilitate wound healing. The cytokines produced by the clot are Transforming Growth Factors (TGF), Platelet Derived Growth Factor (PDGF), Insulin-like Growth Factor (IGF) and Vascular Endothelial Growth Factor.
The steps involved in wound healing are:
- Angiogenesis (formation of new blood cells)
- Immune Control (keeping the immune system from overreacting)
- Harnessing circulating Stem Cells (to make newer tissues)
- Wound Protection by Epithelialization (process of covering denuded epithelial surface)
PRF is a direct stimulator of angiogenesis. Fibrin regulates inflammation via a positive feedback mechanism and provides a scaffold for the epithelial cells to migrate over the clot (and not into the clot). PRF also inhibits keratinocyte growth and enhances mesenchymal stem cell growth. Mesenchymal stem cells help in the generating of new cells and tissues. Hence, PRF actively participates in the physiological wound healing process.
Dr. Kulkarni outlined some of the various applications of PRF in dentistry which include:
- Palatal Wounds are common when palatal grafts are taken. Commonly, periodontal packs, ligature wire supported dressing, gel foam and intraoral bandages are used to aid palatal wound healing. The healing process takes a long time as these materials act as bystanders. Dr. Kulkarni and his team placed a PRF clot over a palatal wound and secured it in place with sling sutures. Since PRF actively participates in the wound healing process, the healing took place faster with controlled bleeding and the patients had reported lesser discomfort.
- PRF is also used as a grafting material for periapical defects. Periapical defects are seen when there are cysts, unhealed ulcers or lesions in towards the root of the teeth. After surgery is done to remove these cysts, a PRF pack can be added to ensure quicker wound healing.
- PRF can be used for wounds caused due to a perforated sinus or during root resection of a molar.
- PRF has been used as an adjunct to coronally positioned flap procedure done for recession or root coverage.
- PRF has been used by several physicians to treat endo perio defects where hydroxyapatite was mixed with PRF and used as a bone graft.
- Liquid form of PRF (specifically leukocyte PRF) is allowed to clot with the bone graft material to form Sticky Bone. This can be used as bone graft which will remain at the place of attachment and not slip off. This is extremely beneficial in extraction socket preservation and reduces alveolar osteitis.
- PRF can be used in modified covering techniques for bone augmentation. Autogenous bone chips were immersed in PRF instead of saline and even after the graft was placed, a PRF clot was placed over it to help with healing and regeneration of the affected gingival area.
- PRF can be used in grafting of jumping spaces and can help with non-specific wound healing applications.
PRF has various other applications in drug delivery, sports medicine, orthodontics, implantology, plastic and aesthetic surgery. Since it accelerates the healing process along with causing much less bleeding and pain, it has garnered a lot of importance in regenerative medicine.