RAPID RESOLUTION OF A SEVERE MULTIFACTORIAL PERI-IMPLANT OSTEONECROTIC LESION IN A MEDICALLY COMPROMISED PATIENT TREATED WITH A METRONIDAZOLE-RELEASING HYDROGEL SCAFFOLD (AEVIZOL): A CASE REPORT

Background: Severe peri-implant osteonecrotic lesions in oncologic and medically compromised patients may result from the convergence of multiple local and systemic factors, including peri-implant infection, repeated oral surgery, smoking, cardiovascular disease, chemotherapy, and previous radiotherapy. Local drug-delivery hydrogels may offer potential advantages in contaminated and poorly vascularized sites. Case Presentation: A 67-year-old man with a history of multiple malignancies, numerous surgical procedures, three myocardial infarctions, active oncologic treatment in 2024, smoking, and complex long-term polypharmacotherapy had undergone original bimaxillary All-on-4 rehabilitation in 2011 using Nobel Speedy implants and long-term reinforced provisional prostheses. In 2025, after rapid necrotizing peri-implant breakdown in the left posterior mandible, a second severe osteonecrotic-infective lesion developed in the anterior mandible following placement of a new implant in the 3.1/3.2 area. On 10/11/2025 the implant was removed. Intraoperatively, the bone appeared grayish, frankly necrotic, friable on curettage, and associated with abundant dense purulent exudate. After careful surgical curettage, the cavity was completely filled with AEVIZOL, a patented hydrogel scaffold with slow metronidazole release. In the AEVIZOL system, metronidazole is preliminarily micronized to below 10 μm using air-nitrogen jet technology in order to prevent overheating and possible deterioration; this process improves its solubility, bioavailability, and affinity for the hydrogel matrix, whose aqueous component is predominant. The site was then sutured with silk. At 15 days, the soft tissues showed favorable trophic recovery. CBCT performed on 13/02/2026 demonstrated substantial healing of the site, allowing reimplantation on 24/03/2026. At re-entry, the bone appeared clinically trophic and compact. Conclusions: In this medically compromised patient with a probable multifactorial peri-implant osteonecrotic lesion, local treatment with AEVIZOL was associated with rapid soft-tissue healing and early radiographic bone recovery sufficient to allow reimplantation after approximately 3.5 months. Further studies are required to clarify the role of metronidazole-releasing hydrogels in high-risk clinical settings.