The long-term favorable prognosis of a single tooth in periodontal disease can be compromised by local destruction (defect) of periodontal tissue. These defects can be inter-radicular (furcation), supracostal (horizontal) and infra-oscillator (vertical) defects. Intra-skeletal (vertical) defects include intra-bone defects, depending on whether only one tooth or two adjacent teeth are equally affected. The craters resemble a cup or cup in the area of the interdental alveolar bone with bone loss almost equal with both adjacent teeth. In the treatment of intraosseous defects, regenerative surgical procedures are used which include access to the defect by flap surgery and placement of bone grafts, membranes, enamel matrix proteins, bone morphogenetic proteins and growth factors or a combination of the products of which above. Clinical case Patient S. M., 31 years old, from Zagreb, non-smoker. Dg. Chronic generalized periodontitis – bilateral in the advanced form of the jaw disease (premolar and molar area) with infrared (vertical) defects. Initial periodontal therapy was performed, after which the patient came once a month for supragingival removal of the deposits. Four months after completion of the initial therapy, re-evaluation was performed and surgery was performed after seven months. The regenerative surgical procedure consisted of accessing a defect between teeth 34 and 36 by flap surgery and positioning of the xenograft and resorbable collagen membrane. Both materials used are completely reabsorbed and de-oxygenated, of equine origin, in granular hydrogel. After surgery, the patient continued to come for the supragingival removal of the deposits once a month and new reassessments and radiological checks were performed six months after the surgery.