QuadroJig: A Reverse-Engineering Analog Protocol for Prosthetic- Periodontal Co-Acquisition in Full-Arch Implant Rehabilitation.

Contemporary full-arch implant rehabilitation increasingly incorporates digital workflows and staged prototyping. However, delayed-loading cases continue to require a structured method for transferring prosthetic and biologic information during the transition from removable to fixed prostheses. This technique report introduces the QuadroJig protocol, an analog-driven, transdisciplinary workflow that enables simultaneous acquisition of implant position, occlusal relationships, esthetic parameters, and peri-implant soft-tissue dimensions. A stabilized intraoral construct derived from a flangeless denture duplicate permits vertical bone sounding to guide prosthetically driven periosteal mapping and execution at prosthetic loading, including gingivoplasty or selective flap modification when indicated. By reverse-engineering the prosthetic tissue junction, the protocol supports fabrication of a prototype-level prosthesis while preserving coordination between prosthetic design and peri-implant anatomy. The construct may be incorporated into either a conventional analog or a hybrid analog-digital workflow, allowing both clinical execution and digital verification. Consequently, the QuadroJig protocol serves as a prosthetic-periodontal co-acquisition and execution workflow, offering a practical approach to delayed full-arch rehabilitation, particularly in digitally underserved clinical arenas.