Accuracy, efficiency, and usability of five navigation modalities for dental implant placement: comparing four AR/MR systems with conventional dynamic navigation

Augmented reality (AR) and mixed reality (MR) technologies are increasingly being integrated into dynamic computer-assisted implant surgery (dCAIS). However, it remains unclear whether the added technical complexity of direct overlay confers any advantages over simpler projection-based approaches or conventional dynamic navigation systems. This study evaluated five navigation paradigms, including four AR/MR approaches: conventional dynamic navigation (DN), AR with screen projection (AR-Screen), MR with an adjustable virtual screen projection (MR-Screen), MR with in situ path projection (MR-Path), and an enhanced MR system featuring in situ path projection combined with real-time depth and angulation feedback (MR-Path-Info). A total of 100 dental implants were placed in 20 phantom models (comprising 2 maxillary and 2 mandibular phantoms per group). The outcomes assessed included global and linear deviations, time consumption, intraoperative complications, and subjective usability. Compared with all the other groups, the MR-Path group exhibited significantly greater angular deviation ( P < 0.001) and coronal-apical apex deviation ( P < 0.001). Additionally, the procedural time was significantly longer in the MR-Path group than in the other paradigms ( P < 0.0001). Task interruption was the most frequently observed complication across all groups. Overall, conventional dynamic navigation and the various AR/MR modalities demonstrated comparable, clinically acceptable levels of accuracy, efficiency, and usability. Notably, however, the use of an implant path overlay alone, which lacked supplementary information feedback, was associated with increased angular and apical deviations, higher complication rates, and a prolonged procedural duration. These findings underscore the importance of integrating real-time feedback mechanisms in AR/MR-guided implant surgery. Further validation through large-scale clinical trials is needed.