The objective of study also is to assess radiographic linear defect depth, and radiographic defect bone density following the application of liquid Platelet-Rich Fibrin (PRF) mixed with denaturated Albumin gel (ALB-PRF) or with bone allograft in periodontal intrabony defects.

Patients and methods: 28 patients will be selected from the outpatient clinic in the Oral Medicine and Periodontology Department, Faculty of Dentistry, Mansoura University according to Pre-operative CBCT that will be used to evaluate the bone destruction pattern. According to the techniques that used in the treatment of periodontal bony defect, the participants will be randomly divided into 4 equal groups: Group I: will include 7 patients, in which the intrabony periodontal defects will be treated with open flap debridement and demineralized freeze-dried bone allograft (DFDBA) and mixed with liquid (PRF). Group II: will include 7 patients, in which participants will be treated with open flap debridement and liquid (PRF) mixed with denatured albumin gel (ALB-PRF) will be injected in periodontal intrabony defects. Group III: will include 7 patients, in which participants will be treated with open flap debridement, DFDBA mixed with liquid (PRF) and collagen membrane. Group IV: will include 7 patients in which participants will be treated with open flap debridement, DFDBA mixed with liquid (PRF) and ALB-PRF membrane.

28 patients will be selected from the outpatient clinic in the Oral Medicine and Periodontology Department, Faculty of Dentistry, Mansoura University according to Pre-operative CBCT that will be used to evaluate the bone destruction pattern.

Sample size will be calculated using G-Power 3.1 for Mac with (α = 0.05, and power = 0.95). One-way ANOVA test will be used and effect size of (0.7) based on the anticipated mean difference of the efficacy of new generation platelet-rich fibrin according Nagy et.al 2021. The total sample size of the four groups will be 28 patients.

Inclusion criteria:

• periodontits stage III according to classification of periodontal and peri-implant disease and conditions (2018).
• Patient with two or three walls or combined bony defect.
• Favorable pattern of occlusion.
• Patient ability to comply with the required recall visits.

Exclusion Criteria:

• Local or systemic diseases that contraindicate surgery.
• Smokers
• Patients with parafunctional habits.
• Pregnancy or lactation.
• Diabetic patient.
• Osteoporosis.
• Immune-suppressed condition that may affect the outcome of the therapy.

I) Study design:

According to the techniques that used in the treatment of periodontal bony defect, the participants will be randomly divided into 4 equal groups:

Group I: will include 7 patients, in which the intrabony periodontal defects will be treated with open flap debridement and demineralized freeze-dried bone allograft (DFDBA) and mixed with liquid (PRF).

Group II: will include 7 patients, in which participants will be treated with open flap debridement and liquid (PRF) mixed with denatured albumin gel (ALB-PRF) will be injected in periodontal intrabony defects.

Group III: will include 7 patients, in which participants will be treated with open flap debridement, DFDBA mixed with liquid (PRF) and collagen membrane.

Group IV: will include 7 patients in which participants will be treated with open flap debridement, DFDBA mixed with liquid (PRF) and ALB-PRF membrane.

II) Surgical Procedures ,liquid PRF and ALB-PRF preparation:

Patients will be premedicated by Amoxicillin 2 gm one hour before surgery as a prophylactic antibiotic, in addition patient will instructed to rinse with a 0.2% chlorhexidine mouth wash for 1 minute immediately prior to surgery.

All patients will be subjected to surgical procedure consisting of the injection of local anaesthetic Articaine hydrochloride 4% with epinephrine (1:100,000) followed by sulcular incision with 15c blade, reflection of a full thickness flap atraumaticlly , open flap debridement using periodontal curettes to remove all tissue tags and granulation tissue. Ethylenediaminetetraacetic acid (EDTA) will be applied to the root surface followed by rinsing with normal saline.

Liquid (PRF) and ALB-PRF Preparation:

As the protocol entails drawing 9 ml of blood into plastic test tubes without anticoagulants and other additives. This is followed by a centrifugation process according to the protocol for liquid PRF by using centrifuge under 2700rpm for 8 min.

The yellow top layer, formed upon centrifugation, consists of platelet-poor plasma that will be collect by a syringe in a volume of 2 ml, liquid PRF and buffy coat that will also be collected by a syringe in a volume of 4 ml. The Platelet-Poor plasma in the syringe will be transferred to a special machine that increases its temperature to 75°C for 10 minutes. ALB-PRF will be prepared by mixing the albumin gel with liquid concentrated growth factor including the buffy coat in a separate syringe by utilizing a female luer lock connector to obtain the injectable ALB-PRF in final ready form.

In group I, the defects will be treated with open flap debridement and DFDBA and mixed with liquid (PRF). In group II, the defects will be treated with open flap debridement and liquid (PRF) mixed with denatured albumin gel (ALB-PRF) will be injected in periodontal intrabony defects. In group III, the defects will be treated with open flap debridement , DFDBA mixed with liquid (PRF) and collagen membrane. In group IV, the defects will be treated with open flap debridement, DFDBA mixed with liquid (PRF) and ALB-PRF membrane. Vertical mattress suture with 5-0 suture will be used to close the wound.

Patients will be instructed to use 0.2% chlorhexidine gluconate mouth wash for 1 minute twice a day for 2 weeks, also maintained on amoxicillin 1gm twice a day for six days postoperatively and Ibuprofen 400 mg will be prescribed to be taken 2 to 4 times a day during meals as analgesic.

Clinical assessment: Pain and bruising will be obtain using Visual Analogue Scales (VAS) on days 0, 3, 5 and 7 post-operatively. While healing will be assess at days 2,7 and 14. The following periodontal indices will be assessed at baseline, 3 and 6 months: Plaque index (PI). Bleeding on Probing (BOP). Pocket depth (PD). Clinical Attachment Level (CAL). Radiographic Assessment: Using cone beam CT (CBCT) scan to assess linear bone defect depth and defect bone density at baseline and 6 months.

Statistical analysis: The data will be collected and statistical analysis will be done using SPSS(statistical package for social sciences) version 2024.

Inclusion Criteria:

• Periodontist stage III according to classification of periodontal and peri-implant disease and conditions (2018).
• Patient with two or three walls or combined bony defect.
• Favourable pattern of occlusion.
• Patient ability to comply with the required recall visits.

Exclusion Criteria:

• Local or systemic diseases that contraindicate surgery.
• Smokers
• Patients with parafunctional habits.
• Pregnancy or lactation.
• Diabetic patient.
• Osteoporosis.
• Immune-suppressed condition that may affect the outcome of the therapy.

after Completing the study ; the data will be available when requested