 Methods: One hundred and twenty subjects with single defects were categorized into four treatment groups: OFD alone, OFD with PRF, OFD with 1 MF and OFD PRF1 MF. Clinical parameters like site specific plaque index PI, modified sulcus bleeding index mSBI, probing depth PD, relative attachment level RAL and gingival marginal level GML were recorded at baseline before surgery and 9 months post-operatively. Percentage radiographic intra-bony defect depth reduction was evaluated using computer-aided software at baseline and 9 months. 