The Present Study Was Performed to Evaluate the Efficacy of Lyophilized-PRF in Treatment of Periodontal Intra-bony Defects

The present study will be performed to evaluate the efficacy of lyophilized platelet-rich fibrin alone and combined with nanocrystalline hydroxyapatite in treatment of periodontal intra-bony defects through: 1. Primary outcomes: * The clinical parameters including: Probing pocket depth (PPD) reduction and clinical attachment level (CAL) gain. * The radiographic parameters including: Marginal bone level (MBL), bone-defect fill. 2. Secondary outcome: The level of BMP-2 in Gingival crevicular fluid (GCF).