Aim: Growth factors (GFs) as platelet derived growth factor (PDGF) and transforming growth factor (TGF-beta), found in platelet beta-granules also present in platelet-rich-plasma (PRP), accelerate bone revascularization and regeneration and for this reason they have been employed successfully in dental and maxillofacial surgery. Platelet concentrate is commonly used for this purpose as long as platelet release reaction and the consequent GFs loss are avoided. To reduce this phenomenon we set up an easy and fast procedure for preparing a satisfying clotted PRP by adding CaCl2 only (no exogenous thrombin).
Methods: ELISA essay has been used to measure PDGF and TGF-beta in plasma, platelets and serum and platelet GMP-140, with the cytofluorometric technique in order to quantify the degranulation entity.
Results: In the 13 examined patients receiving clotted PRP to enhance bone regeneration in post-extractive alveolar sockets, PRP showed no sign of platelet activation (degranulation) and short recalcification times (8-12 min). The autologous clotted PRPs specimen have been evaluated in laboratory in terms of GFs percent: 76% of initial GFs content could be recovered in clotted PRP. This result confirms the absence of platelet degranulation in our procedure.
Conclusions: Significant clinical results in alveolar bone regeneration are reached only with a high percentage of GFs inserted in bone matrix, avoiding early platelet degranulation.