This case concerns a patient wearing a complete maxillary denture and a mandibular removable partial prosthesis, who attended the clinic because of discomfort caused by the latter and the need to improve her oral rehabilitation. Clinical examination revealed a Class III intermaxillary relationship, and CBCT confirmed severe horizontal bone atrophy, particularly in the posterior mandibular regions, where the width was less than 4 mm at some sites.

The treatment plan was based on making use of the residual bone by strategically placing 3.0 mm narrow-platform implants in both the maxilla and mandible, combined with larger-diameter implants as required by the anatomical and prosthetic conditions. This approach made it possible to treat areas of horizontal atrophy by placing the implants directly, without prior regenerative procedures, ridge expansion or other complex reconstructive techniques.

The surgical technique involved preparing the implant sites by low-speed biological drilling, with implant selection and distribution adapted to the bone available in each region. In the mandible, four of the five reduced-diameter implants were included in an immediate-loading protocol, while the remaining implant was left unloaded as part of a two-stage protocol because of its lower insertion torque. The implants were splinted to larger-diameter implants using a screw-retained provisional restoration on abutments, fabricated with articulated bars and fitted 48 hours after surgery. One year later, the definitive mandibular restoration was fabricated following placement and loading of the maxillary implants, for which a similar protocol was used.