Purpose: The aim of this prospective randomized clinical trial was to evaluate 10 years of treatment of patients receiving a mandibular implant-retained overdenture (IRO) or a conventional complete denture (CD). Materials and Methods: One hundred twenty-one edentulous patients were treated with an IRO (2 endosseous implants, n = 61) or a conventional CD (n = 60). Clinical aspects and patient satisfaction were evaluated. One year after placement of the denture, unsatisfied patients of the CD group were given the opportunity to receive implants. Results: In the IRO group, 4 implants were lost during the first year and 4 implants were lost during the next 4 years. Between 5 and 10 years, no implants were lost (survival rate: 93%). In the CD group, 24 patients (40%) chose an IRO between 1 and 10 years. Discussion: Patients in the IRO group were significantly more satisfied than patients in the CD group after 1 year (satisfaction score 8.3 versus 6.6 on a scale of 1 to 10), after 5 years (7.4 versus 6.4), and after 10 years (7.7 versus 6.8). Conclusion: The mean satisfaction score of the CD group (including patients who later received implants) was still lower than that of the IRO group, in spite of the opportunity for retreatment with IROs. Endosseous implants had a high survival rate after 10 years of follow-up. Keywords: clinical trial, complete denture, dental implants, overdenture