<unk>  <unk>  or leukocyte- and<unk>  (L-PRF) is a second-generation PRP where autologous<unk> s and leukocytes are present in a complex<unk>  matrix to accelerate the healing of soft and hard tissue and is used as a tissue-engineering scaffold for endodontics. To obtain<unk> , required quantity of blood is drawn quickly into test tubes without an anticoagulant and centrifuged immediately. Blood can be centrifuged using a tabletop centrifuge from 3-8 minutes for 1300 revolutions per minute. The resultant product consists of the following three layers; topmost layer consisting of<unk>  poor plasma,<unk>  clot in the middle, and red blood cells (RBC) at the bottom.<unk>  is available as a<unk>  clot.<unk>  clot can be removed from the test tube using a sterile tweezer-like instrument. After lifting, the RBC layer attached to the<unk>  clot can be carefully removed using a sterilized scissor.<unk>  activation in response to tissue damage occurs during the process of making<unk>  release several biologically active proteins including;<unk>  alpha granules,<unk> ‑derived growth factor (PGDF), transforming growth factors‑β (TGF‑β), vascular endothelial growth factor (VEGF), and epidermal growth factor. Actually, the<unk> s and leukocyte cytokines play important parts in role of this biomaterial, but the<unk>  matrix supporting them is the most helpful in constituting the determining elements responsible for real therapeutic potential of<unk> . Cytokines are immediately used and destroyed in a healing wound. The harmony between cytokines and their supporting<unk>  matrix has much more importance than any other<unk>  derivatives.
Platelet-rich fibrin
Thrombin–antithrombin complex
Fibrin monomer
Fibrinogen
Thrombin
Platelet-activating factor
Fibrinopeptide
Plasminogen 