This case concerns a 69-year-old woman who wore complete removable dentures in both arches and presented because her mandibular denture lacked retention, causing pain and difficulty during mastication. She requested replacement of the lower denture with an implant-supported fixed prosthesis. Radiographic and tomographic examinations showed marked vertical atrophy of the mandible, particularly in the posterior sectors, where limited residual bone height and the proximity of the inferior alveolar nerve restricted the placement of conventional implants. To avoid a restoration supported solely by anterior implants, with the resulting distal cantilevers, placement of six implants distributed along the mandibular arch was planned. These included two extra-short implants, 5.5 mm long and 5.5 mm in diameter, in the posterior regions, in conjunction with a vertical bone augmentation technique. The posterior implants were placed slightly supracrestally, maintaining a safety distance from the inferior alveolar nerve. Autologous bone obtained by biological drilling was stored in PRGF-Endoret and subsequently used as graft material around the supracrestal portions of the implants, with the aim of achieving the vertical augmentation required for their integration into the restoration. Four 10 mm-long implants were placed in the anterior region, and an immediate-loading provisional restoration was fitted. After six months, the planned vertical bone growth around the posterior implants had been achieved, allowing them to be incorporated into the definitive restoration. This made it possible to fabricate a complete mandibular prosthesis supported by six parallel implants distributed as far as the distal sectors, avoiding the need to tilt the posterior implants or use prosthetic cantilevers

The definitive prosthesis consisted of a hybrid resin restoration with a CAD/CAM-milled framework, screw-retained on multi-unit abutments and splinting all six implants. Treatment restored masticatory function, vertical dimension and arch width, with improved aesthetics compared with the initial presentation.