Immediate Loading of 5.2-mm Ultra-Short Implants Supporting Maxillary Overdentures in the Severely Atrophic Maxilla: A Prospective Pilot Study

Background: Severe maxillary atrophy often precludes placement of conventional dental implants and frequently requires invasive bone augmentation procedures. This prospective pilot study evaluated a treatment concept using immediately loaded 5.2-mm ultra-short implants connected by a patient-specific CAD/CAM inter-implant bar system (VD CLIC BAR®) to support maxillary overdentures. Methods: Thirteen completely edentulous patients with severe maxillary atrophy (Cawood–Howell Class V or VI) were treated with six to eight immediately loaded 5.2-mm ultra-short implants connected by a patient-specific CAD/CAM inter-implant bar (VD CLIC BAR®) supporting a maxillary overdenture. The primary outcome was implant survival. Secondary outcomes included oral health-related quality of life (OHIP-14), self-reported chewing ability (VAS), implant stability (Periotest), and prosthetic rehabilitation. Results: A total of 96 initial implants and 8 additional implants were placed following early implant failures. The primary implant survival rate after two years was 83.3%. Implant failures occurred predominantly during early healing and were unevenly distributed across the cohort. Early failures were managed by placement of additional ultra-short implants, enabling definitive implant-supported rehabilitation in all patients. Periotest values demonstrated a significant increase in implant stability over time (p < 0.001). Median OHIP-14 scores improved from 32.0 (IQR 20.0–44.0) at baseline to 4.0 (IQR 1.0–20.0) at two years (p = 0.006). Median chewing ability at two years was 82.7 (IQR 50.1–91.9). Conclusions: This prospective pilot study demonstrates the feasibility of an immediately loaded treatment concept using 5.2-mm ultra-short implants splinted with a patient-specific CAD/CAM inter-implant bar (VD CLIC BAR®) to support maxillary overdentures in patients with severe maxillary atrophy. Although early implant failures occurred and required placement of additional ultra-short implants in some patients, all patients ultimately achieved functional implant-supported rehabilitation. These preliminary findings require confirmation in larger controlled studies with longer follow-up.