Study of Two Different Putty Bone Grafts in Treatment of Intrabony Defects with the Aid of Intramarrow Penetration Technique

to evaluate and compare efficacy of two different putty forms for both Demineralized Bone Matrix allograft (DBM) and nanocrystalline hydroxyapatite (NCHA) in treatment of intrabony defects with the aid of intramarrow penetration, A total of twenty patients will be diagnosed with stage III grade B periodontitis according to the Caton classification. They will be selected from the clinic of Department of Periodontology and Oral Medicine, Faculty of Dentistry, Mansoura University Patients will be classified into two groups: * Group I: in this group, ten patients with intrabony defect will be treated by open flap debridement with decortication followed by placement of nanocrystalline hydroxyapatite in putty form as grafting material. * Group II: in this group, ten patients with intrabony defect will be treated by open flap debridement with decortication followed by placement of Demineralized Bone Matrix allograft putty as grafting material. Clinical assessment: including the following parameters: 1. Plaque Index (PI). 2. Gingival Index (GI). 3. Clinical Attachment Level (CAL) 4. Probing Depth (PD) Radiological parameters * The height of the defect: Distance from the CEJ to the alveolar crest (AC) * Depth of the defect: Distance from CEJ to the base of the defect * Width of the defect: Highest point of the AC to the root adjacent to the defect * Defect angle: Two lines that represent the root surface of the involved tooth and the bone defect surface