Material Jetting (MJ) 3D printing technology is promising for the fabrication of highly realistic surgical simulators, however, the changes in the mechanical properties of MJ materials after post-printing treatments and over time remain quite unknown. In this study, we investigate the effect of different post-printing processes and aging on the mechanical properties of a white opaque and rigid MJ photopolymer, a white flexible MJ photopolymer and on a combination of them. Tensile and Shore hardness tests were conducted on homogeneous 3D-printed specimens: two different post-printing procedures for support removal (dry and water) and further surface treatment (with glycerol solution) were compared. The specimens were tested within 48 h from printing and after aging (30-180 days) in a controlled environment. All groups of specimens treated with different post-printing processes (dry, water, glycerol) exhibited a statistically significant difference in mechanical properties (i.e. elongation at break, elastic modulus, ultimate tensile strength). Particularly, the treatment with glycerol makes the flexible photopolymer more rigid, but then with aging the initial elongation of the material tends to be restored. For the rigid photopolymer, an increase in deformability was observed as a major effect of aging. The hardness tests on the printed specimens highlighted a significant overestimation of the Shore values declared by the manufacturer. The study findings are useful for guiding the material selection and post-printing processing techniques to manufacture realistic and durable models for surgical training.

Background: Augmented-reality (AR) navigation is emerging as a means of turning pre-operative cone-beam CT data into intuitive, in situ guidance for difficult tooth removal, yet the scattered evidence has never been consolidated nor illustrated with a full clinical workflow. Aims: This study aims to narratively synthesise AR applications limited to dental extractions and to illustrate a full AR-guided clinical workflow. Methods: We performed a PRISMA-informed narrative search (PubMed + Cochrane, January 2015–June 2025) focused exclusively on AR applications in dental extractions and found nine eligible studies. Results: These pilot reports—covering impacted third molars, supernumerary incisors, canines, and cyst-associated teeth—all used marker-less registration on natural dental surfaces and achieved mean target-registration errors below 1 mm with headset set-up times under three minutes; the only translational series (six molars) recorded a mean surgical duration of 21 ± 6 min and a System Usability Scale score of 79. To translate these findings into practice, we describe a case of AR-guided mandibular third-molar extraction. A QR-referenced 3D-printed splint, intra-oral scan, and CBCT were fused to create a colour-coded hologram rendered on a Magic Leap 2 headset. The procedure took 19 min and required only a conservative osteotomy and accurate odontotomy that ended without neurosensory disturbance (VAS pain 2/10 at one week). Conclusions: Collectively, the literature synthesis and clinical demonstration suggest that current AR platforms deliver sub-millimetre accuracy, minimal workflow overhead, and high user acceptance in high-risk extractions while highlighting the need for larger, controlled trials to prove tangible patient benefit.

Augmented reality (AR) represents an emerging technology that is increasingly being integrated into surgical navigation across various medical disciplines, including orthopedic surgery. This preclinical study investigated the application of AR in orthopedic oncology and performed a comparative assessment of two head-mounted displays (HMDs): Microsoft HoloLens 2 and Magic Leap 2. The study evaluated the feasibility of AR-assisted tracing of planned osteotomies for bone tumor resections in orthopedic surgery. The objective was to evaluate the visualization capabilities, spatial guidance performance, and user interaction provided by the two AR platforms under controlled preclinical conditions. Accuracy of AR-guided tracing of planned osteotomies was quantified using custom cutting guides incorporating grooves of 1 mm, 2 mm, and 3 mm to measure deviations from the planned osteotomy lines. Both AR HMDs were tested under identical experimental conditions, and their performance and accuracy were comparatively analyzed. Magic Leap 2 demonstrated a trend toward greater accuracy in AR-guided tracing of osteotomies, achieving 82%, 95%, and 100% accuracy within 1 mm, 2 mm, and 3 mm thresholds of the planned osteotomy lines, respectively. In comparison, the HoloLens 2 achieved 65%, 85%, and 95% accuracy within the same respective thresholds. Ergonomic assessment also suggested favorable user comfort and handling characteristics for Magic Leap 2. Further studies involving larger cohorts and comparisons with established navigation techniques are required to confirm the potential advantages of HMD-based AR guidance for bone tumor resections and other orthopedic procedures.