To evaluate the accuracy of conventional polyether impressions (Impregum™ Penta™ Soft from 3M®) and digital scans produced by five intra-oral scanners (IOSs): Trios 3 (3Shape®), Trios 4 (3Shape®), Primescan (Dentsply Sirona®), CS3600 (Carestream®) and I500 (Medit®) scanners in maxillary free-ended partial edentulism for long-span implant-supported prostheses in partially edentulous arch. This in vitro study involved the impression of a maxillary working model with free-end partial edentulism, in which six implants were placed before digitization using a desktop scanner to generate a digital reference model. Conventional impressions and digital scans with five IOSs were obtained. Conventional impressions were digitized using the same desktop scanner. Each digital STL file of conventional or digital impressions was superimposed over the reference STL file to enable comparison. Trueness was assessed by calculating angles and distance deviations. For precision, dispersions of values around their means were also measured. The mean distance deviation was significantly higher for conventional impressions (454.24±334.70 µm) than for IOSs (ranging from 160.98±204.48 µm to 255.56±395.89 µm) (p<0.001). The mean angular deviation was high with conventional impressions (1.82±1.51°), intermediate with CS3600 (1.38±1.42°), Primescan (1.37±2.54°) and Trios 4 (1.30±0.64°) scanners, and lower with I500 (0.97±0.75°) and Trios 3 (1.01±0.85°) scanners (p<0.001). The dispersion of distance values around their means was lowest with Trios 3 and I500, followed by CS3600, Primescan, and Trios 4 scanners respectively, and higher for conventional impressions (p<0.001). The dispersion of angular values was smallest with I-500, Trios 3, and Trios 4 compared with other groups and was highest with Primescan (p<0.001). Within the limits of the current study, Trios 3 scanner exhibited the highest accuracy, followed by I500, Trios 4, CS3600, Primescan, and conventional impressions respectively. IOSs might be reliable for the fabrication of an implant-supported prosthesis. In vivo studies are required to confirm these findings. Passive adaptation of the implant-supported framework is a challenge when rehabilitating patients with maxillary free-end partial edentulism. While conventional impressions remain a reliable and clinically validated technique in implantology, the Trios 3, I500, Trios 4, CS3600, and Primescan scanners could potentially reduce mechanical complications, given their demonstrated higher accuracy compared to conventional impressions for long-span implant-supported prostheses in partially edentulous arch.

Background. Digital dentistry continues to evolve, offering improved accuracy, efficiency, and patient experience across various prosthodontic procedures. Many previous reviews have focused on digital applications in prosthodontics. But the use of a fully digital workflow for full-arch implant-supported prostheses in edentulous patients remains an emerging and underexplored area in the literature. Objective. This article presents a comprehensive methodological review of the digital workflow in full-arch implant-supported rehabilitation. It follows a structured literature exploration and synthesizes relevant technological processes from patient assessment to prosthetic delivery. Methods. The relevant literature was retrieved from the PubMed database on 20 June 2024, to identify the most recent and relevant studies. A total of 22 articles met the eligibility criteria and were included in the review. The majority included case and technical reports. Results. The review illustrates the integration and application of digital tools in implant dentistry, including cone-beam computed tomography (CBCT) exposure, intraoral scanning, digital smile design, virtual patients, guided surgery, and digital scanning. The key findings demonstrate multiple advantages of a fully digital workflow, such as reduced treatment time and cost, increased patient satisfaction, and improved interdisciplinary communication. Conclusions. Despite these benefits, limitations persist due to the low level of evidence, technological challenges, and the lack of standardized protocols. Further randomized controlled trials and long-term clinical evaluations are essential to validate the effectiveness and feasibility of a fully digital workflow for full-arch implant-supported rehabilitation.