Second Generation Platelet Concentrations/ Platelet-Rich Fibrins/Regenerative Stem Cell Therapies
In today’s dental surgery, in addition to various graft materials or with graft materials
In combination, some growth factors are also used in surgery. Growth factor is a general name given to hormones that stimulate many cellular activities such as proliferation, chemotaxis, differentiation and production of extracellular matrix proteins.
These activities are the basic steps of regeneration. For example, Bone Morphogenetic Protein (BMP) stimulates mesenical northern cells and plays an osteoinductive role.
transform Efficiency Growth Factor b-1 (TGF b-1) stimulates chemotaxis of osteoblasts, stimulates endothelial cell and fibroblast apoptosis, conversion of fibroblasts to myoblasts. Vascular Endothelial Growth Factor (VEGF) enhances angiogenesis.
Platelet-derived growth factor (PDGF) stimulates proliferation of mesenical cymal progenitor cells and increases chemotaxis of neutrophils and monocytes..
Epidermal Growth Factor (EGF) is responsible for the proliferation of epithelial cells, Insulin-Like Growth Factor1 (IGF-1) stimulates osteoblast and bone matrix synthesis. Hyeon et al. In an animal study conducted in 2007, they compared autogenous graft with autogenous graft + PRF application in sinus lifting operations. In the histological examination performed after the animals were sacrificed, the amount of bone in the test group (autogenous graft + PRF) was found to be higher than in the control group.
The reason has been shown to be the activation of the protein structure in the autogenous graft by PRF and the tendency of osteoblasts to adhere to the environment, which is called Choukroun et al. In a similar human study they carried out, they stated that the graft mixed with PRF formed new bone more quickly than the graft application alone. The role of PRF in soft tissue healing. It is thought to be similar to PRP. In a study, no difference was found in the comparison of standard CSF and CSF/PRF Throat et al. In a study published in 2011, they compared conventional flap and flap/PRF in the treatment of periodontal intraosseous defects.
Obtaining the PRF
PRF is obtained by centrifuging the venous blood taken from the patient at 3,000 rpm for 15 minutes. The success of this system, which is quite simple, is due to its rapid centrifugation after blood is obtained from the patient. Venous blood taken into vacuum tubes should be centrifuged within the first few minutes. In the first minutes of the centrifugation, the platelets are mechanically attached to the walls in a closed system, and their cytoplasm is fragmented, and the factors and their contents are released. Since no anticoagulant is added to the obtained blood, it tends to polymerize naturally. PRF is obtained without the addition of any anticoagulant or synthetic material, eliminating the criticisms received by PRP. The layer of PRF, which is removed from the centrifuged tubes with the help of a sterile press, is peeled off with the help of a hand tool. The serum of the PRF obtained is impregnated with the gas buffer and a membrane form with high resistance is obtained. The membrane can be shaped as desired by cutting it with scissors according to the area to be used. It is used for acceleration and regeneration purposes .
Platelet concentrations according to their content and method of obtaining
1-Platelet Rich Plasma (PRP)
2-Platelet Rich Fibrin (PRF) is divided into two classes.
TZP: PLASMA RICH IN THROMBOCYTE
PRP, the first product derived from blood, is an autogenous blood clot containing high concentrations of platelets and growth factors.
It can be used in gel form when thrombin and CaCl2 are added.
It has widespread use in medicine, dentistry and veterinary medicine. Del Fabbro et al., in their systematic study published in 2011, evaluated the possible effect of PRP on the treatment of periodontal intraosseous defects, furcation defects and gingival recessions.
It has been determined that PRP can contribute to healing when used in combination with graft material in intraosseous and furcation defects, but it does not contribute to healing in guided tissue regeneration procedures and in the treatment of gingival recessions.
PRF: FIBRIN RICH FROM THROMBOCYTE
It is obtained by concentrating the platelets and cytokines, the second of the platelet concentrations, in the fibrin network.
Unlike PRP, it is preferred that it is obtained without the addition of any anticoagulant or synthetic material, its production time is short and its cost is low. It has been the reason for TZF . Since platelet cytokine activity plays a key role in obtaining PRF, the formation steps must be well defined. It consists of blood, plasma and cells. Plasma; It contains protein, sugar, fat, vitamins and hormones. Blood cells are erythrocytes, leukocytes and platelets. Platelets are megakaryocytes in the bone marrow.
occurs. The lifespan of a platelet in the bloodstream is 8-10 days. They are colorless, nucleusless disc-shaped and contain many granules such as fibrinogen and growth factors in their cytoplasm. In a healthy individual, they are found in the blood of 150,000-450,000/mm3. In the biological wound healing steps, thromboplastin substance is released from the platelets as a result of bleeding in the vessels. Thromboplastin becomes active and converts prothrombin, which is produced in the liver and whose precursor is vitamin K, to thrombin with the help of calcium ions. Thrombin converts the fibrinogen in the blood cytoplasm into a fibrin network and the first step plug is formed in the area.
The fibrin mesh captures circulating stem cells and activates vascularization in the wound area. It has been found that the fibrin matrix directly activates angiogenesis. Platelets contain growth factors and cytokines that initiate wound healing as well as forming the clot.
There are growth factors such as TGFb-1, PDGF, EGF, IGF-1, VEGF and BMP in the a-granules of platelets. They play an important role in the healing steps. In PRF, all these growth factors are placed in the wound area with increased concentrations.
Conclusion: It can be said that it aims to increase the platelet concentration and the number of fibrin networks.
Application areas of PRF in dentistry :
1. Treatment of periodontal defects
2. Sinus lifting operations
3. Socket augmentation
4. Crest augmentation
5. Treatment of gingival recession
6. Covering open wound surfaces
7. Treatment of furcation defect
As a result, PRF’s current content that accelerates regeneration, autogenous and easy availability, cheap and reliable is the reason why it is preferred.
Dr. Suhan SUNGUR