The aims of periodontal regeneration are to obtain new periodontal attachment, new bone formation and less gingival recession. Different surgical techniques have been used with different regenerative materials, including barrier membrane, bone grafts and active biological compounds, or combinations. The results are promising and can be maintained on a long-term basis. This case report was a 5-year follow-up after periodontal regeneration, following a combination therapy with collagen membrane and demineralized freeze-dried bone allograft in treating a mandibular incisor with severe periodontal intrabony defect.