Inclusion Criteria:  Patient-related criteria:  Patient consulting in the outpatient clinic. Able to tolerate surgical periodontal procedures. Patient ready to perform oral hygiene instructions. Compliance with the maintenance program. Provide informed consent. Accepts the 12 months follow-up period.  Teeth related criteria:  Mature permanent tooth. Tooth with two or three-walled intra-bony defect, with CAL ≥ 5mm and intra osseous defect ≥ 3mm.  Exclusion Criteria:  Patient-related criteria:  Medically compromised patients. Pregnant or nursing women. Uncooperative patients. Smokers.  Teeth related criteria:  Teeth with one wall intra-bony defect. Teeth with supra-bony defects. Teeth with grade II or III mobility. Teeth with proximal carious defects or proximal faulty restorations.