Feasibility of the Impression Reference (IR) Technique for Open-Flap Immediate Loading Full-Arch Rehabilitation of the Atrophic Maxilla: A Case Series

Background: Open-flap immediate loading full-arch rehabilitation of the atrophic edentulous maxilla remains clinically demanding because flap elevation modifies the soft-tissue anatomy and stable anatomical landmarks for digital registration are limited. The Impression Reference (IR) technique was developed as a workflow-oriented strategy to provide a recognizable spatial reference during dataset matching and prosthetic transfer. This case series evaluated the feasibility of completing an IR-assisted digital workflow in patients undergoing open-flap immediate full-arch rehabilitation of the atrophic maxilla. Methods: This feasibility case series included 26 completely edentulous patients with severe maxillary atrophy treated with immediate full-arch implant-supported rehabilitation using an Impression Reference-assisted digital workflow. No control group was included and no quantitative accuracy analysis was performed. Workflow-related and prosthetic-transfer outcomes were evaluated descriptively, including completion of dataset matching, prosthetic transfer, IR coupling within the predefined 0.2 mm tolerance, delivery of the immediate prosthesis, clinically acceptable passive fit, prosthetic congruence with the pre-surgical digital plan, and surgical complications. Results: The IR-assisted workflow, dataset matching, prosthetic transfer, and immediate prosthetic delivery were completed in all 26 patients. All patient-specific digital projects complied with the nominal 0.2 mm CAD coupling tolerance, and the associated components could be completely seated and remained clinically stable during use. Clinically acceptable prosthesis fit and prosthetic congruence with the pre-surgical project were recorded in all immediate restorations according to the predefined clinical criteria. No intraoperative surgical complications were documented in the available records. Conclusions: Within the limitations of this descriptive case series, the IR-assisted workflow was feasible in all the included patients undergoing open-flap immediate loading full-arch rehabilitation of the atrophic maxilla. Successful workflow completion should not be interpreted as quantitative evidence.