Periodontal intrabony defects represent a major challenge for the clinician in periodontal therapy. If left untreated, these defects represent a risk factor for disease progression and additional attachment and bone loss.

All patients will receive full mouth scaling and root planing and be re-evaluated to assess patient cooperation and maintaining good oral hygiene. Subjects who showed persistent PPD ≥ 5 mm with radiographic evidence of periodontal intrabony defect presence will be included and will be randomly allocated to one of two treatment groups.One group will be treated by surgical treatment and the defects filled by freeze-dried bone allograft mixed with enamel matrix derivative. second group will be treated by surgical treatment and the defects filled by freeze-dried bone allograft .Clinical periodontal parameters (PI, GBI, PPD, CAL) will be re-evaluated at 3, 6 and 9 months after surgery. CBCT will be taken after 9 months of surgery and the defect measurements will be recorded

primary goal of periodontal therapy is not arrest the tissue destruction caused periodontal disease only, but also to reconstruct the tissue lost caused by infectious process. Periodontal intrabony defects represent a major challenge for the clinician in periodontal therapy. If left untreated, these defects represent a risk factor for disease progression and additional attachment and bone loss. Surgical intervention is considered the treatment of choice for deep intrabony defects, which have not resolved following completion of cause-related periodontal therapy.

In general, periodontal studies showed that healing of periodontal defect after conventional periodontal therapy by collagenous tissue with epithelial cell migration within the gingival connective tissue and along the root surface. Therefore, a various of methods and techniques used to prevent epithelial ingrowth to the defect site and permit only a selective periodontal cells proliferation in attempt to regenerate periodontal tissues. Regenerative procedures including the use of certain types of bone replacement materials, barrier membranes, enamel matrix derivative (EMD), or various combinations thereof have been shown to facilitate periodontal regeneration characterized histologically by formation of root cementum, periodontal ligament, and alveolar bone and result superior in clinical, and radiographical patient reported outcomes compared to access flap surgery alone.

Various bone graft and bone substitutes materials can be helpful in the tissue restoration. This bone graft include autogenous bone graft, allografts, xenografts, and alloplastic materials. Autologous bone is considered the gold standard because of its biological activity due to vital cells and growth factors. Yet, the autologous bone from intra-oral donor sites is of restricted quantities and availability, and the bone tissue obtained from the iliac crest is described to show faster resorption. Moreover, the harvesting of autologous bone often requires a second surgical site associated with an additional bone defect, potential donor site morbidity limiting their application.

In recent years, the use of allogeneic human bone has been favored worldwide, and several histological and morphological studies have demonstrated that, there is no difference in the final stage of incorporation and new bone formation between allografts and autografts. Thus, the application of processed allogenic bone tissue is a reliable and predictable alternative.

Allogeneic bone graft refers to bony tissue that is harvested from one individual and transplanted to a genetically different individual of the same species, principally osteoconductive, although it may have some osteoinductive capability, depending on how it is processed.

Maxgraft® is allograft bone substitute processed by the Cells+Tissuebank Austria with a special cleaning process (Allotec® process). The purification process keeps the structural features and the interconnected macroporosity of human bone. It preserve natural bone structure and collagen content, therefore it serves as a scaffold for natural bone regeneration and has the potential of complete remodeling into patients' own bone. It is available as purely cancellous as well as cortico-cancellous granules and blocks.

Recently, better outcomes have been reported with a combination of xenograft and enamel matrix derivative (EMD) as it combines the osteoconductive and space-making properties of bone grafts with the ability of bioactive materials to stimulate periodontal regeneration. The major components of EMD are amelogenins, a family of hydrophobic porcine tooth-derived proteins. They account for more than 95% of the total EMD protein content. Other proteins found in the enamel matrix include enamelin, ameloblastin, amelotin, apin and various proteinases, which have found in trace amounts in EMD. EMD adsorbs on decontamined root surfaces and alveolar bony defects and forms an insoluble scaffold complex.

To the best of our knowledge, no previous studies have been performed for assessment of the efficacy of using emdogain with maxgraft.

Inclusion Criteria:

• Age range between 30-50 years.
• Patients with stage III periodontitis, will be diagnosed on the basis of probing pocket depth and clinical attachment loss.
• Presence of at least one or more radiographically detectable intrabony defect with clinical periodontal pocket depth (PPD) ≥5 mm, clinical attachment loss ≥5 mm, and radiographic depth of the intrabony defect ≥3 mm.
• No periodontal therapy within the last 6 months

Exclusion Criteria:

• Smoker and alcoholic patient.
• Patient with any signs, symptoms or history of systemic disease that might affect the periodontium and interfere with healing process.
• Pregnant patients.
• Patient who has traumatic occlusion.
• Uncooperative patient