Clinicians frequently encounter implants with undocumented histories that necessitate prosthetic revision. This report describes two cases of multi-implant restorations for undocumented implants, facilitated by an implant finder service. In both cases, existing prostheses were nonfunctional. The Korean Academy of Oral and Maxillofacial Implantology implant finder service accurately identified the unknown implant systems, providing specifications for compatible components, enabling reuse of fixtures that might otherwise have required removal. This approach preserved existing structures and enhanced patient comfort. The restorations demonstrated successful function over follow-up periods of 2.5 and 6 years, respectively. Given the diagnostic challenges posed by radiographic limitations and the wide variety of implant systems, implant finder services represent an invaluable tool for clinicians.