Periodontal disease is one of the most prevalent afflictions affecting the human beings. When occurs, it destroys the tooth supporting structures like periodontal ligament, cementum and alveolar bone. If untreated, tooth may become mobile and finally may get exfoliated. The ultimate goal of periodontal therapy is creation of an environment that is conducive to maintaining the patient’s dentition in health, comfort and function. Periodontal therapy is directed not only at inflammation control but also at pocket reduction and associated bone defect. The shift in therapeutic concepts from resection to regeneration has significantly impacted the practice of periodontology. Regeneration of lost bone and periodontal attachment improves the support of the tooth and its prognosis. Bone replacement grafts have been shown to produce greater clinical bone defect fill from flap debridement alone. In most of the clinical studies, the osseous grafted sites have outperformed the non grafted sites in the regeneration of the lost periodontal structures. This research work evaluated the efficacy of ?-tricalcium phosphate plus hydroxyapatite in the treatment of periodontal infrabony defects.