Purpose: This study was carried to evaluate and compare the regenerative capacity of PRF mixed with bioactive glass versus PRF mixed with bioactive glass combined with collagen membrane in treatment of intrabony defects. This assessment was based on TGF- β1 concentration in GCF. Patients and materials: A sample of 36 intra bony defects were randomaly divided into; Group I: bioactive glass mixed with PRF. Group II: collagen membrane with bioactive glass mixed with PRF. Group III: open flap debridement only. The GCF TGF-β1 was analyzed by ELIZA at base line, one and three months postoperatively and evaluate the efficacy of PRF system in intrabony defects clinically and radiographically at base line, one, three and six months. Results: Mean TGF-β1 concentrations were significantly reduced in one and three months post-surgery when compared to baseline. The mean values of TGF-β1 at 3 months was 0.12± 0, 0.4±0.01 and 0.11±0.01 in groups I, II, III respectively. There was a statistically significant reduction in periodontal probing depth that was 6±0.97 and gain in CAL 3.87±2.14 mm both in group II after 6 months. There was a highest bone density increase was18±5.84 in group I. Conclusions: The assessment of cervical TGF-β1 levels is considered to reflect the ongoing processes in the surrounding periodontal tissues. In addition, utilizing PRF mixed with bioactive glass might be considered a promising regenerative therapy.