['The aim of this clinical study were to compare the clinical efficacy of ankaferd blood stopper (ABS) when used in combination with autogenous cortical bone graft (ACB) in the treatment of intrabony periodontal defects.', 'The study was planned as a split-mouth design. Fifteen patients with chronic periodontitis at 30 sites (six men, nine women; 42 ± 7 years) were included. Treatment sites had probing pocket depths (PPD) of ≥ 6 mm and osseous defect depths of ≥ 4 mm as radiographically assessed. Following the initial periodontal therapy, patients were randomly assigned to two treatments in contralateral areas of the dentition: ACB + ABS or ACB alone. At baseline and 6 mo after surgery, clinical parameters of plaque index, gingival index, PPD, clinical attachment level and gingival recession (GR) were recorded. The primary outcome variable was the change in clinical attachment level between baseline and 24 wk after surgery. Gingival crevicular fluid samples were collected immediately before surgery and at 2, 4, 6, 12 and 24 wk after the surgery. Gingival crevicular fluid volume was calculated and vascular endothelial growth factor levels in gingival crevicular fluid were measured.', 'PPD decreased, clinical attachment level improved and gingival index decreased significantly in response to both modes of treatment (p < 0.05). Both treatment modalities resulted in a significant gain in radiographic bone levels compared to baseline (p < 0.05). Intergroup comparisons showed that there was a significantly higher gain in clinical attachment level in the ABS/ACB group compared to ACB group (p < 0.05) with significantly less GR (p < 0.05). Similarly, vascular endothelial growth factor concentration in gingival crevicular fluid was significantly higher in the ABS/ACB group at postoperative weeks 2 and 4 compared to the ACB group (p < 0.01).'] Does ankaferd blood stopper enhance healing after osseous grafting in patients with intrabony periodontal defects?