Wearable Augmented Reality for Dental Implant Navigation: From Experimental Models to Clinical Application-A Scoping...

Background: Accurate three-dimensional positioning of dental implants is fundamental for long-term prosthetic success. While static guided surgery and traditional dynamic navigation present intrinsic limitations related to physical bulk or hand-eye coordination (the "look-away" phenomenon), Augmented Reality (AR) via Head-Mounted Displays (HMDs) promises to overcome these barriers by superimposing virtual holograms directly onto the surgical field. Objectives: The aim of this scoping review is to map the existing literature to evaluate the positioning accuracy, workflow efficiency, and ergonomic/technical barriers of HMD-based AR navigation systems in implant dentistry. Methods: A systematic search was conducted across the PubMed, Scopus, Web of Science, and Cochrane Library databases, following the PRISMA-ScR guidelines. In vitro, ex vivo, and clinical studies utilizing AR headsets (e.g., HoloLens) for implant guidance, reporting quantitative data on accuracy and/or qualitative data on usability issues, were included. Results: Eleven studies were included (7 in vitro, 1 ex vivo, 3 clinical). Accuracy showed a strong dependence on case complexity: for standard implants, the mean error at the entry point ranged between 0.33 and 1.51 mm, which is comparable to s-CAIS techniques. However, in complex scenarios (zygomatic implants), significant deviations were reported (up to 5.64 mm and 9.60°). The main barriers to routine adoption identified include tracking instability due to line-of-sight interruption, device weight, and the vergence-accommodation conflict. Conclusions: AR dynamic navigation demonstrates promising potential. Nevertheless, current evidence relies predominantly on in vitro studies that fail to fully replicate real-world surgical complexities. Persistent technical and ergonomic barriers, such as tracking instability and hardware limitations, indicate that the technology remains largely in a preclinical phase and is not yet suitable for routine clinical application. Further advancements toward markerless tracking systems, lighter headsets, and rigorous in vivo trials are required.