The use of injectable platelet-rich fibrin (i-PRF) in both surgical and non-surgical dental treatments has become increasingly widespread. Hard tissue grafts can produce sticky bone, and bone gain can have a positive effect on intrabony defects frequently seen in periodontal disease, compared to grafts alone. This study aims to clinically and radiographically evaluate the effectiveness of using bovine-derived xenogenic bone grafts in combination with i-PRF and bovine-derived xenogeneic bone grafts alone in patients with intrabony defects and stage III periodontitis.