Introduction: In recent years, the indication for the placement of dental implants has expanded consistently. Therefore, more and more patients are treated with implant supported restorations resulting in increasing implant associated complications. Inflammatory peri-implant diseases represent the most frequent complications. For peri-implantitis, especially in advanced cases, a surgical approach is still the gold standard. However, to date no preferential surgical protocol has been established. Previous surgical techniques recommended the removal of the intralesional granulation tissue followed by grafting of the bony defect. Material und Methods: The present article demonstrates the systematic treatment protocol for inflammatory peri-implant diseases performed in our department at Hannover Medical School and a new surgical technique. The aim of this technique is to preserve as much intralesional granulation tissue as possible. The efficiency of the granulation tissue preservation technique has already been proven for regenerative periodontal therapy. Three case reports illustrate the practical application and the effectiveness of this new surgical technique in the regenerative treatment of peri-implantitis. Results and Conclusion: The present case series demonstrates a significant gain of clinical attachment level and a remarkable bone fill, proving the success of the new surgical therapy protocol. In addition to the preservation of multipotent mesenchymal stem cells and blood vessels, the enhanced soft tissue support with an endogenous matrix resulted in less postoperative mucosal recessions. This is the main advantage of the new surgical technique. Keywords: decontamination protocol, granulation tissue preservation technique, peri-implantitis treatment, regenerative treatment of peri-implantitis