Tooth-supported overdentures remain a valuable yet often underutilized treatment option for the rehabilitation of partially edentulous patients. Preserving natural teeth as overdenture abutments helps maintain alveolar bone, improves proprioception, and enhances retention and stability compared with conventional complete dentures. The present case report describes the prosthetic management of a patient requiring mandibular rehabilitation in whom remaining teeth were strategically retained and restored with a tooth-supported overdenture using O-ring attachments, while a conventional complete denture was fabricated for the maxilla. Careful diagnosis, evaluation of inter-arch space, and patient preference guided the treatment plan, with elective endodontics performed on the selected abutments followed by precise preparation and chairside incorporation of the attachment components. The O-ring system provided satisfactory retention, stability, and patient comfort, with successful function maintained during a one-year follow-up. This report reinforces the clinical relevance of tooth-supported overdentures as a minimally invasive and cost-effective alternative when anatomical, functional, or financial factors limit the use of implant-based or bar-retained designs, and highlights the importance of meticulous planning and periodic maintenance to ensure long-term success.