This retrospective analysis of five reentry cases reports on the clinical defect healing after combined surgical resective/regenerative therapy of advanced peri-implantitis. A second surgery was necessary because of a clinical need for additional treatment procedures at the respective implant sites after healing periods of 8 months to 6.5 years. All patients underwent the same standardized procedure including access flap surgery, implantoplasty at bucally and supracrestally (> 1 mm) exposed implant parts, surface decontamination, and augmentation of the intrabony (Class I) components using a natural bone mineral and a native collagen membrane. Clinical defect resolution (DR) of the Class I component was evaluated. In two patients, clinical and radiographic signs suggested a reinfection (ie, case 3-mesial aspect; case 5-mesial and distal aspects). Mean DR values ± standard deviation were 59.4% ± 47.59% (95% confidence interval [CI], 0.31%-118.49%). When infected aspects were excluded, resulting values were 85.76% ± 4.86% (95% CI, 78.02%-93.50%). The presented surgical procedure was associated with a clinically important DR in advanced peri-implantitis defects.