Computer-aided design and computer-aided manufacturing (CAD-CAM) complete-arch implant-supported fixed prostheses have become popular in recent years and offer several advantages over traditional fabrication techniques. However, they also present challenges, and careful treatment planning is required, particularly for zirconia implant-supported fixed prostheses layered with feldspathic porcelain. This clinical report describes the use of a CAD-CAM high-density polymer implant-supported diagnostic prosthesis to verify the accuracy of the implant impression and evaluate the maxillomandibular relationship, esthetics, and phonetics of the planned CAD-CAM definitive implant-supported fixed prosthesis before CAM processing.