BACKGROUND The purpose of this study was to compare patients' subjective experiences with respect to long-term satisfaction with mandibular implant-retained overdentures versus conventional complete dentures. METHODS Among 85 completely edentulous patients, 60 were treated with four one-stage titanium implants and overdentures retained by a cast bar with extracoronal attachments. These patients constituted the experimental group, and were subsequently evaluated clinically over a period of up to 6 years. The other 25 patients constituted the control group and were treated with conventional complete dentures without implant retained. All the patients (n = 60) in the experimental group responded to questions on their experiences before and after treatment with the implant-retained overdentures. Sixty percent (n = 15) of the 25 patients in the control group responded to the questionnaire. RESULTS No implants or restorations failed during the observation period. The experimental group, however, showed significant differences with the control group in terms of their responses to the questionnaire. CONCLUSIONS The use of implants to retain and support the overdenture improved comfort and gave the experimental patients greater self-confidence in social interactions, in addition to more effective oral rehabilitation. The results demonstrate that the effects of rehabilitation of the mandibular arch with an implant-retained overdenture are predictable.