Explantation and Guided Repositioning of Two Mandibular Implants for Rehabilitation With an Implant-Mucosa-Supported Overdenture in a Patient With Advanced Peri-Implantitis: A Case Report.

Peri-implantitis is a biological complication that can compromise long-term implant survival and, in advanced cases, may indicate explantation. In patients with mandibular edentulism rehabilitated with implant-retained overdentures, the management of advanced peri-implant disease is particularly challenging when systemic factors and unfavorable peri-implant tissue conditions coexist. We report the case of a 73-year-old woman with a medical history of rheumatoid arthritis and Sjögren's syndrome who was wearing an implant-retained mandibular overdenture supported by two intraforaminal implants. She presented with prosthetic instability, peri-implant pain, and clinical and radiographic findings consistent with a Class IIIc combined peri-implant bone defect with advanced severity at the left mandibular site. Treatment included explantation of the affected implants followed by digitally planned, prosthetically guided immediate placement of two new intraforaminal implants. A subsequent soft tissue augmentation procedure with de-epithelialized free gingival grafts was performed to increase the band of peri-implant keratinized mucosa. Definitive rehabilitation was completed with an implant-mucosa-supported overdenture retained by low-profile Equator attachments (Rhein83, Bologna, Italy). At three months after loading, clinical and radiographic evaluation showed peri-implant stability, healthy soft tissues, and adequate prosthetic retention and function. The short follow-up does not allow conclusions regarding long-term outcomes, but the case illustrates a feasible workflow for managing advanced peri-implantitis in a medically compromised patient when conservative or regenerative strategies are considered unpredictable.