1. Platelet Rich Plasma Gacheon Gil dental center Dept. of periodontology JIYOON LEE

2. Definition • PRP (Pletelet rich plasma) :concentrated source of autologous PLTs. • Platelet concentrate • APG(Autologous platelet gel) • Buffy coat

3. Platelet? • Anuclear piece of cytoplasm • Include hemostasis, α-granule,lysosomal granule, dense granules

4. Α-granules • At least 7 different growth factors that stimulate bone & soft tissue healing • PDGF aa,bb,ab • TGF b1,b2 • VEGF • EGF

5. Α-granules • Do not contain insulin-like growth factors nor BMP • Adhesion molecule fibronectin vitronectin fibrin

6. The role of PLT in wound healing • Injury • PLT activation • Within 10 min,α-granule migrate to the cell membrane surface and secrete growth factors ( inactive →active form)

7. Days of operation

8. 7 days later • PLT exhausted after 7 days • Macrophage by low oxygen tension, acidity, lactate concentration • Secrete same growth factors • Activated until it is down regulated by the restoration of normal oxygen tension

9. Day 3rd

10. 17days • Graft is completely permeated by new capillaries • Initial osteoid formation • Osteoclast resorb osteoid and BMP released • New bone formation and maturation

11. Days 14

12. Platelet는 cell replicaion, vascular ingrowth,bone cell differentiation, early osteoid formation .. 등의 acativit 가 일어나도록 initiator 역할 담당함.

13. Growth factors in PLT

14. PDGF(pletelet-derived growth factors) • PDGF aa,bb,ab • Promoting angiogenesis, re-epithelization,formation of granulation tissue • Chemotaxis for mesenchymal cell(OB< FB,Macrophage…),monocyte,neutrophiles

15. TGF(transforming growth factor) • TGF β1,β2 • Stimulate cell replication similar to PDGF • Stimulate matrix production and guide differentiation towards cartilage or bone

16. Most potent multifuctional regulator of bone cell metabolism(OB에 TGF receptor 많다.)

17. VEGF(vascular endothelial growth factor) • Effects on endothelial cells

18. EGF(epithelial growth facator) • Effect limited on the basal cells of skin and mucus membrane

19. The mechanism of growth factor effects on cells Inactive state

20. Activation activation

21. Clinical effects of PRP on bone regeneration Platelet RBC Normalblood PRP

22. 4~7 times above a concentration of platelets than peripheral blood plates level • Bone mineral density 1.6~2,2 times increased • Rapid bone formation & earlier maturation.

23. Trabecular area Nativemandible Autogenous BG PRP

24. Clinical effects of PRP on soft tissue healing • Split thickness skin graft 후 donor site의 healing 양상을 비교함

25. 6 days Thrombin side : 5% epithelization 95% granulation tissue PRP side ; 95% epithelization 5% granulation tissue

26. 6 months Thrombin side : scarring hypo and hyper-pigmentation area가 두드러짐 PRP side ;less scarring Much less pigmentation change

27. Patient discomfort • Patient discomfort decrease

28. Epithelization

29. 6days ↔ ↔

30. 1 months

31. Mechanism • Growth factors contained PRP stimulated complete revascularization earlier and more complete • Early epithelial covering of exposed granulation tissue and C.T, the development of dermis is the mechanism that reduced scarring and a maximum regeneration of normal skin pigmentation

32. Bovine thrombin issue • Bovine thrombin + CaCl2 :clot initiator to activate PRP • CJD(Creutzfeldt-jakob disease) : mad cow disease • Postop bleeding : 100mg/ml of bovine factor Ⅴa

33. Contraindications • Pre-existing coagulation defect : thrombocytopenia, hypofibrinogenia… • Hypersensitivity to bovine thrombin

34. Clinical application

35. Ridge preservation

38. Any Questions??