Abstract: Objective: To explore the restoration strategy and effect of implant-supported removable partial denture (ISRPD) for complex mandibular KennedyⅡ defects after tumor surgery. Diagnosis and Treatment: This case report described a 29-year-old male patient. Following tumor resection of the right mandible, vascularized iliac bone graft, and simultaneous implant placement at sites , the patient presented with missing teeth from , forming a complex mandibular Kennedy ClassⅡ defect that crossed the midline and features a unilateral distal extension. After multidisciplinary sequential treatment, considering the suboptimal conditions of the grafted bone area and insufficient function of conventional removable partial denture (RPD), an ISRPD was designed and fabricated using a reimplanted implant at site  combined with the original implants at sites , utilizing bar-clip attachments. Results: The restoration was smoothly placed and stably retained. The denture adopted a clasp-free design, eliminating metal exposure in the anterior region and enhancing aesthetic appearance. The patient recognized the restoration effect. The restoration could be independently inserted and removed by the patient, facilitating thorough cleaning of peri-implant tissues and the prosthesis itself, demonstrating excellent maintainability. Conclusions: For complex mandibular Kennedy II defects after tumor surgery, when fixed restoration is limited, ISRPD is an effective restoration solution. Through multidisciplinary collaboration, strategic implant placement, and reasonable design, the function of the denture can be enhanced, overcoming the deficiencies of traditional RPD.

Key words: implant-supported removablepartial denture (ISRPD), Kennedy II defect, occlusal reconstruction, attachment, prosthetic design