Rescue Therapy With Quad Zygoma After Failure of Full-Arch Implant Rehabilitation: A Retrospective Study With a Mean Follow-Up of 8 Years

Abstract

OBJECTIVES: To evaluate the long-term clinical outcomes of quad zygomatic implants (ZIs) as a rescue therapy for patients with failed full-arch implant rehabilitation in the maxilla due to advanced peri-implantitis. MATERIAL AND METHODS: This was a retrospective cohort study of all patients treated with the Quad Zygoma Protocol. Primary outcomes included the ZI survival and success rates, and secondary outcomes, the prosthetic success rate and complications. RESULTS: The study population included 28 consecutive patients who received 112 ZIs between 2006 and 2024, with a mean follow-up of 8.2 ± 4.1 years. In 23 patients, a total of 113 failed conventional implants were removed, and 48 ZIs were immediately placed into the explantation sites. The ZI survival rate was 98.2%, with two ZIs requiring removal due to late complications. The implant success rate was 93.5%, and prosthetic success was achieved in 96.4% of cases. Sinusitis was diagnosed in 8 patients (28.5%) at a mean of 5.92 years postoperatively; all cases were successfully managed medically without implant loss. Soft tissue recession occurred in 9.8% of cases, while oroantral fistula and facial fistula were each observed in 0.9% of implants. CONCLUSIONS: The Quad Zygoma Protocol may represent a reliable and predictable option for the rescue of failed maxillary full-arch implant rehabilitations. Despite a relatively high prevalence of sinusitis, favorable long-term clinical outcomes were achieved with appropriate management.