Purpose: To report and analyze long-term treatment outcomes in a patient cohort with severe periodontal disease treated with an employed protocol combining use of implants and double-crown prosthetic support. Materials and Methods: A convenience sample of 16 patients with generalized severe periodontal disease were prosthodontically managed with support from 83 dental implants and 21 removable prostheses using a double-crown concept (11 implant-tooth supported and 10 implant supported). Each patient was examined 2 to 4 weeks before scheduled teeth extraction and examined again following treatment completion at the time of insertion of the superstructures. Subsequent recall examinations were performed every 3 months over a 6- to 20-year period. Predetermined clinical parameters were recorded at each session, and intraoral radiographs were taken after insertion of the superstructure and at intervals of 1, 3, 5, 10, and 20 years. Results: No implant or tooth loss occurred during the individual observation periods. Mucositis was recorded around 65% of the implants and was accompanied by additional maxillary marginal bone loss around 27.7% of the implants. Mean marginal bone loss at implant sites after 5 years was 0.75 ± 0.66 mm, and after 20 years was 1.50 ± 1.45 mm. Moderate bone loss around teeth was registered after 5 years (2.8%) and 20 years (7.3%). No significant differences were found between implants in patients with tooth-implant- supported and those with implant-supported double-crown restorations. Conclusion: These results suggest that severely periodontally compromised patients can be successfully managed in the long term with the described clinical protocol.