UNASSIGNED: Headholders or skull clamps serve as indispensable tools in neurosurgery, facilitating the precise positioning and stabilization of the head for surgery. The realm of neurosurgical training in cadaver labs presents a clear challenge due to the lack of suitable non-clinical headholders.
UNASSIGNED: We describe a 3D printed stainless-steel headholder for use in neurosurgical cadaver lab training.
UNASSIGNED: Computer-aided design software was used to design a headholder, utilizing a three-pin skull fixation. Through an iterative process involving a plastic 3D printed prototype, ultimately a robust model was manufactured using a 3D stainless-steel printer.
UNASSIGNED: The headholder was fixed to a multi-angle adjustable vise, enabling optimal positioning to support simulation of neurosurgical approaches and dissection training by neurosurgical residents and staff in the cadaver lab.
UNASSIGNED: This custom-made headholder offers an effective solution for secure fixation of cadaver skulls during neurosurgical training, contributing to practicality and efficiency in cadaver dissection. Despite the lack of evidence-based guidelines for neurosurgical headholder use, this device provides a valuable tool for neurosurgical trainees to practice proper placement, understand associated complications, and improve their hands-on skills. The digitally available 3D model can be optimized, shared, and further improved by other neurosurgical units and trainees, fostering collaborative advancements in neurosurgical training.

Three-dimensional-printed silicone rubber foams, with their designable and highly ordered pore structures, have shown exceptional potential for engineering applications, particularly in areas requiring energy absorption and cushioning. However, optimizing the mechanical properties of these foams through structural design remains a significant challenge. This study addresses this challenge by formulating the research question: How do different 3D-printed topologies and printing parameters affect the mechanical properties of silicone rubber foams, and how can we design a novel topological structure? To answer this, we explored the mechanical behavior of two common structures-simple cubic (SC) and face-centered tetragonal (FCT)-by varying printing parameters such as filament spacing, filament diameter, and layer height. Furthermore, we proposed a novel two-level 3D-printed structure, combining SC and FCT configurations to enhance performance. The results demonstrated that the two-level SC-SC structure exhibited a specific energy absorption of 8.2 to 21.0 times greater than the SC structure and 2.3 to 7.2 times greater than the FCT structure. In conclusion, this study provides new insights into the design of 3D-printed silicone rubber foams, offering a promising approach to developing advanced cushioning materials with superior energy absorption capabilities.

BACKGROUND: In revision total hip arthroplasty (THA), the advent of porous custom-made triflange acetabular implants with 3D scan planning offers a new perspective to improve implantation accuracy and anatomical restoration of the center of rotation (COR). This issue was investigated using CT-scan as the measurement tool, but in limited series (±10 cases) and without investigating the factors that may influence errors in positioning. Therefore we performed a retrospective study aiming to: (1) assess the placement accuracy of such implants with respect to the preoperative planning, (2) examine whether the volume of bone to be resected in order to apply the implant had an impact on this accuracy, (3) assess if errors in position at surgery had any influence on function, complications and survival.
OBJECTIVE: Preoperative planning could be accurately reproduced when implanting porous custom-made acetabular implants, and that accuracy would decrease in proportion to the volume of bone to be resected METHOD: Twenty patients undergoing THA revision with porous custom-made acetabular implants were included in this single-center retrospective study. Mean follow-up was 17.9 months ± 9.4 [2-45.1]. Preoperative planning was performed using 3D scanographic modeling. A post-operative CT scan was performed to assess implantation accuracy in terms of orientation and COR restitution. Demographic data, Oxford scores, complications and survival were recorded.
RESULTS: Mean deviation from the preoperative planning in inclination, anteversion and rotation were 4.3 ° ± 2.5, 6.1 ° ± 4.7, and 7 ° ± 4.6, respectively. Restoration of the COR showed a mean deviation of 2.1 ± 1.3 mm anteroposteriorly, 2.5 ± 2 mm mediolaterally and 2.2 ± 1.3 mm proximodistally. In total, 45% (9/20) of implants were positioned with perfect restoration of orientation (±10 °) and COR (±5 mm). The mean planned bone resection was 8.1 ± 4.9 cm3, with placement accuracy and COR restitution decreasing significantly when the volume of bone to be resected exceeded 2.7 cm3. One dislocation was found (5%, 1/20). Survival at last follow-up was 100%, the mean Oxford score at follow-up was 31.7 ± 7.9 [16-52], without being influenced by errors in position or COR restitution.
CONCLUSIONS: In total 45% of the implants restored an orientation and a COR as planned, particularly when the volume of bone to be resected is less than 2.7 cm3. Although these are complex cases with large amounts of bone loss, 3D manufacturing could give us hope of greater precision. The link between better precision and low bone resection volume could be an area to develop with the manufacturer in order to improve results.
METHODS: III; diagnostic using CT in transversal retrospective study.

Non-plasma technologies are being extensively investigated for their potential to mitigate microbial growth through the production of various reactive species. Predominantly, studies utilise atmospheric non-thermal plasma to produce plasma-activated liquids. The advancement of plasma-liquid applications has led to the investigation of plasma-activated aerosols (PAAs). This study aimed to produce a rapid-prototyped plasma-activated aerosol setup and perform chemical and anti-bacterial characterisation on the resultant activated aerosols. The setup was produced using stereolithography 3D printing, and air was used as the carrier gas. The novel design of the device allowed for the direct production of PAAs without the prior generation of plasma-activated water and subsequent aerosolisation. The generated PAAs were assessed for nitrite, hydrogen peroxide and ozone content using colourimetric assays. Anti-bacterial efficacy was tested against three human pathogenic strains: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Salmonella enterica. It was observed that nitrite and ozone contact concentration increased with exposure time, yet no hydrogen peroxide was detected. The generated PAAs showed significant zones of no growth for all bacterial strains. These devices, therefore, show potential to be used as anti-bacterial disinfection technologies.

A global issue that requires attention is the duality between the shortage of needles for regular vaccination campaigns and the exponential increase in syringe and needle waste from such campaigns, which has been exacerbated by the COVID-19 pandemic. In response to this problem, this study presents a 3D printed needleless injector based on thermocavitation. The work focused on investigating the interaction of the resulting liquid jets with skin phantoms at different concentrations (1-2%), emphasizing their impact and penetration depth in a repetitive regime. The injector was designed and fabricated from a semi-transparent polymer using a high-resolution 3D printer, allowing the ejection of liquid jets with velocities up to ~ 73 m/s. The impact of these jets on skin phantoms was evaluated using a high-speed camera. After 6 consecutive liquid jets (1% concentration), a maximum penetration depth of ~ 2.5 mm was achieved, delivering approximately 4.7 µL. For the highest concentration (2.0%) and the same number of shots, the penetration depth was reduced to ~ 0.6 mm with a delivered volume of ~ 0.7 µL. An important finding of this study is that the liquid jet with the highest pressure does not cause the maximum penetration depth, but is the result of a series of successive shots. In addition, the velocity and shape of the ejected jet are determined by the amount of solution and the meniscus formed inside the injector. These findings advance the development of precise and efficient thermocavitation-based injectors with broad potential applications in medical and pharmaceutical fields.

OBJECTIVE: To compare the treatment effectiveness of digitized and 3D-printed repositioning splints with that of conventional repositioning splints in the treatment of anterior displacement of the temporomandibular joint disc.
METHODS: This retrospective study included 96 patients with disc displacement of the anterior temporomandibular joint. They were treated with either digitally designed and 3D-printed repositioning splints or traditional splints and followed up for at least six months. Changes in signs and symptoms such as pain and mouth opening before and after treatment were recorded to evaluate treatment outcomes.
RESULTS: During the first month of treatment, both the digitally designed and 3D-printed repositioning splint groups (Group B) and the traditional repositioning splint group (Group A) showed significant increases in mouth opening, with increases of 4.93 ± 3.06 mm and 4.07 ± 4.69 mm, respectively, and there was no significant difference between the two groups. Both groups had a significant reduction in visual analog scale (VAS) pain scores, with Group B showing a greater reduction of 1.946 ± 1.113 compared to 1.488 ± 0.978 in Group A (P < 0.05). By the sixth month, Group B\'s mouth opening further improved to 38.65 ± 3.22 mm (P < 0.05), while Group A\'s mouth opening did not significantly improve. Regarding pain, Group A\'s VAS score decreased by 0.463 ± 0.778 after one month, and Group B\'s score decreased by 0.455 ± 0.715; both groups showed significant reductions, but there was no significant difference between the two groups.
CONCLUSIONS: Compared with traditional repositioning splints, digitally designed and 3D-printed repositioning splints are more effective at reducing patient pain and improving mouth opening. 3D-printed repositioning splints are an effective treatment method for temporomandibular joint disc displacement and have significant potential for widespread clinical application.

This case report aims to present the successful restoration of the atrophic partially edentulous posterior mandible using custom-made subperiosteal implants. The fixed prosthesis restoration was achieved using computer-aided design and computer-aided manufacturing technologies and 3D metal printing methods. The partially edentulous 58-year-old patient expressed a preference not to undergo bone augmentation procedures. The patient with teeth in the anterior mandible was treated with 2 separate custom-made subperiosteal implants. A custom-made implant was fabricated from sintered titanium using machined subperiosteal implants with a universal external connection. Subperiosteal implants offer several advantages over conventional bone grafting plus intraosseous implant placement techniques, such as the simple, 1-step procedure for atrophic jaws, streamlining the treatment process and reducing the overall time involved. Treatments using subperiosteal implants can be an alternative solution for individuals with severely atrophic jaws. Longer term studies in a larger sample are warranted to corroborate previous reports.

UNASSIGNED: Dentures aim to replicate natural dentition\'s esthetics and functions as much as possible. With computer-aided design/computer-aided manufacturing (CAD/CAM) technology, dentistry had a new renaissance with workflow and materials.
UNASSIGNED: The aim is to compare the fracture toughness of the milled, 3D-printed, and conventional polymethyl methacrylate (PMMA) to those processed conventionally.
UNASSIGNED: 10 CAD MILLED PMMA BLOCKS, 10 3D PRINTED PMMA BLOCKS, and 10 CONVENTIONAL (HEAT CURE) PMMA BLOCKS.
UNASSIGNED: A significant difference was seen in the mean flexural module when compared among three study groups as P < 0.05. It was found to be maximum in CAD/CAM PMMA, followed by conventional heat cure and 3D-printed PMMA.
UNASSIGNED: Formlabs and Dentca (3D-printed) were significantly weaker in fracture toughness compared to Leucitone 199 (conventional) (P < 0.05). Leucitone 199 (conventional) was significantly weaker in fracture toughness compared to Avadent (CAD CAM) (P < 0.05).

BACKGROUND: Children with dental caries are treated with stainless steel metal crowns (SSC), but the aesthetics and precision still need to be improved. Currently, both 3D-printed resin crowns (PRC) and computer-aided design/computer-aided manufacture (CAD/CAM) resin crowns (CRC) meet the clinical requirements for crown applications in terms of strength, production time, cost, and aesthetics.
OBJECTIVE: This study replaced SSC with customized resin crowns by 3D printing and CAD/CAM.
METHODS: In this study, PRC, CRC, and SSC were used for incisor and molar restorations, and 60 crowns were made with 10 for each group. The fabrication efficiency, surface characteristics, marginal fit, and stability of the two different crowns were evaluated.
RESULTS: PRC and CRC show superior color and surface characteristics, though production times are longer (5.3-12.4 times and 3.3-9.1 times, respectively) than for SSC (p < .05). They, however, can be completed within 80 min. Edge gaps for PRC and CRC are significantly lower (13.0-19.2 times and 13.0-13.7 times) than for SSC (p < .05). All materials exhibit good stability.
CONCLUSIONS: The 3D-PRCs and CAD/CAM resin crowns may replace SSCs as a potential choice for clinical child caries.

The capability to produce suture material using three-dimensional (3D) printing technology may have applications in remote health facilities where rapid restocking of supplies is not an option. This is a feasibility study evaluating the usability of 3D-printed sutures in the repair of a laceration wound when compared with standard suture material. The 3D-printed suture material was manufactured using a fused deposition modelling 3D printer and nylon 3D printing filament. Study participants were tasked with performing laceration repairs on the pigs\' feet, first with 3-0 WeGo nylon suture material, followed by the 3D-printed nylon suture material. Twenty-six participants were enrolled in the study. Survey data demonstrated statistical significance with how well the 3D suture material performed with knot tying, 8.9 versus 7.5 (p = 0.0018). Statistical significance was observed in the 3D-printed suture\'s ultimate tensile strength when compared to the 3-0 Novafil suture (274.8 vs. 199.8 MPa, p = 0.0096). The 3D-printed suture also demonstrated statistical significance in ultimate extension when compared to commercial 3-0 WeGo nylon suture (49% vs. 37%, p = 0.0215). This study was successful in using 3D printing technology to manufacture suture material and provided insight into its usability when compared to standard suture material.