This case concerns a 69-year-old woman with complete edentulism of the maxilla and a history of failure of an implant-supported overdenture. Clinical examination revealed inflammatory changes in the mucosa associated with the prosthesis and a single remaining implant with circumferential bone loss; its poor prognosis indicated that it should be explanted. CBCT confirmed severe vertical bone atrophy throughout the maxilla, with a residual bone height of 1–3 mm, marked pneumatization of the maxillary sinuses and proximity of the nasal floor to the alveolar ridge.

In view of these findings, complete maxillary rehabilitation was planned using 4.5 mm-long ultra-short implants and a single 5.5 mm-long implant at position 27, combined with minimally invasive bone-elevation techniques to make use of the limited residual volume and avoid extensive reconstructive procedures. In the posterior sectors, transcrestal sinus elevation was performed simultaneously with implant placement, while a nasal floor elevation technique was used in the premaxilla to enable implant placement and stabilisation.

The surgical technique was based on individualised three-dimensional planning, the use of a surgical guide derived from the diagnostic wax-up, and preparation of the implant sites using low-speed biological drilling. The drilling sequence was adapted to the characteristics of the available bone to achieve primary stability. The elevations were performed using particulate autologous bone collected during drilling and combined with PRGF - ENDORET®, without the need to collect grafts from additional donor sites. Placement of an anterior implant was deferred during the first procedure because of a small perforation of the nasal mucosa, which was treated with PRGF - ENDORET®. Once healing had been confirmed, the outstanding 4.5 mm implant was placed six months later.

Once osseointegration had been achieved, a progressive-loading protocol was initiated using a provisional resin prosthesis on articulated bars, screw-retained to multi-unit abutments (MULTI-IM®). Subsequently, once the last implant had been brought into functional loading, a definitive hybrid resin prosthesis on a CAD/CAM-milled framework was fabricated.