['To compare three implant systems in patients with severely resorbed mandibles 1 year after insertion of the mandibular denture.', 'A prospective multicenter randomized clinical trial.', 'Centers at University of Nijmegen and Groningen.', 'Three different implant systems were used: the transmandibular implant, the IMZ and the Brånemark system. Treatment was assigned to 88 patients according to a balanced allocation method. Evaluation included clinical and radiographic parameters. A Clinical Implant Performance scale (CIP) was constructed based on all conceivable complications of the different implant systems.', 'During the healing period 1 IMZ- and 1 BRA-implant were lost. One TMI was removed after functional loading. The results of the clinical and radiographic parameters and the CIP-scale showed no significant differences between the three implant systems.'] Do [ Comparison of dental implant systems for mandibular overdentures ]?