Introduction
infection, periodontium, CM, Periodontitis
CLOT, DISEASE, INFECTION, COLLAPSE, PERIODONTITIS, EVENTS
Periodontitis is a chronic inflammatory wide- spread infection with exceptionally offensive mutilation of the periodontium. Regenerative periodontal surgery aims to restore periodontal tissues lost during progression of the disease. For vertical bone defects regenerative interventions included the use of enamel matrix derivatives, Nd:YAG laser, bone grafts, guided tissue regeneration (GTR), and biologic modifiers to achieve regeneration [Naturally, activated platelets in the wound clot secrete coagulation factors, cytokines, and GF to orchestrate the physiological events of wound healing [Both GTR and PRF have their limitations in the literature; Despite collagen membranes (CMs) used in GTR do not require removal from the wound site and could retain their structural identity throughout the degradation process, several obstacles exist that pose GTR technique to collapse in clinical situations including contamination, uncontrolled degradation rates, uncontrolled barrier function, and mechanical collapse of the membrane. Most importantly, it possesses a limited capability for regeneration [In the present study, it was speculated that CM can be used to preserve the GF concentrations released by L-PRF enhancing the clinical and radiographic outcomes in treating infrabony pockets. Therefore, the aim of the present study was to investigate the clinical and radiographic outcomes for infrabony defects treated with L-PRF with and without CM coverage and to evaluate the secretory profile of PDGF and VEGF during early stages of periodontal tissue healing.