Roland Told

Bone fractures pose a serious challenge for the healthcare system worldwide. A total of 17.5% of these fractures occur in the distal radius. Traditional cast materials commonly used for treatment have certain disadvantages, including a lack of mechanical and water resistance, poor hygiene, and odors. Three-dimensional printing is a dynamically developing technology which can potentially replace the traditional casts. The aim of the study was to examine and compare the traditional materials (plaster cast and fiberglass cast) with Polylactic Acid (PLA) and PLA–CaCO3 composite materials printed using Fused Filament Fabrication (FFF) technology and to produce a usable cast of each material. The materials were characterized by tensile, flexural, Charpy impact, Shore D hardness, flexural fatigue, and variable load cyclic tests, as well as an absorbed water test. In addition, cost-effectiveness was evaluated and compared. The measured values for tensile strength and flexural strength decre...

3D printing is an emerging and disruptive technology, supporting the field of medicine over the past decades. In the recent years, the use of additive manufacturing (AM) has had a strong impact on everyday dental applications. Despite remarkable previous results from interdisciplinary research teams, there is no evidence or recommendation about the proper fabrication of handheld medical devices using desktop 3D printers. The aim of this study was to critically examine and compare the mechanical behavior of materials printed with FFF (fused filament fabrication) and CFR (continuous fiber reinforcement) additive manufacturing technologies, and to create and evaluate a massive and practically usable right upper molar forceps. Flexural and torsion fatigue tests, as well as Shore D measurements, were performed. The tensile strength was also measured in the case of the composite material. The flexural tests revealed the measured force values to have a linear correlation with the bending b...

Supplementary Dataset for the publication entitled "A state-of-the-art guide to the sterilization of thermoplastic polymers and resin materials used in the additive manufacturing of medical devices" , including the detailed results of mechanical tests, DSC-TGA measurements and the images of scanning electron microscopy. If this dataset is being used in any publication, please cite the original article as well. Main folder: Supplementary. Supplementary folder includes the detailed results of mechanical tests (Mechanical_Results.xls; all materials of different sheets within the file), DSC-TGA measurements (DSC-TGA_Results.docx) and the images of scanning electron microscopy (SEM_Pictures folder). Within the SEM_Pictures folder, images are deposited by the type of material, and each material has images about the broken surface ("Fracture") and intact surface ("Surface"). Photo about white resin test speciment is included in the main folder, before, and aft...

We report the additive manufacturing of a heat-exchange device that can be used as a cooling accessory in a wire myograph. Wire myography is used for measuring vasomotor responses in small resistance arteries; however, the commercially available devices are not capable of active cooling. Here, we critically evaluated a transparent resin material, in terms of mechanical, structural, and thermal behavior. Tensile strength tests (67.66 ± 1.31 MPa), Charpy impact strength test (20.70 ± 2.30 kJ/m2), and Shore D hardness measurements (83.0 ± 0.47) underlined the mechanical stability of the material, supported by digital microscopy, which revealed a glass-like structure. Differential scanning calorimetry with thermogravimetry analysis and thermal conductivity measurements showed heat stability until ~250 °C and effective heat insulation. The 3D-printed heat exchanger was tested in thermophysiology experiments measuring the vasomotor responses of rat tail arteries at different temperatures ...

Force provided by elastomers used in orthodontics can be affected by several factors present in the oral cavity. The aim of our study was to investigate the role of mouthwashes, toothbrushing, and smoking in the force decay of such elastomers. Tensile strength, changes in the force continuously exerted, and force decay of elastic chains (Ortho Organizer and Masel Short Power Chain) and elastic ligatures (Dentaurum and Masel) by two separate manufacturers were measured. Measurements were initially made on untreated elastics, followed by exposure to different environmental factors including cigarette smoke, toothbrushing (mechanical plaque control), and two different mouthwashes (chemical plaque control). Changes on the surface of the elastics were studied with scanning electron microscopy (SEM). Untreated Masel elastic ligature showed lower tensile strength than Dentaurum elastic ligature (2339 cN vs. 3660 cN), while significantly higher tensile strength was measured for Ortho Organi...

Additive manufacturing technologies are essential in biomedical modeling and prototyping. Polymer-based bone models are widely used in simulating surgical interventions and procedures. Distal forearm fractures are the most common pediatric fractures, in which the Kirschner wire fixation is the most widely used operative method. However, there is still lingering controversy throughout the published literature regarding the number of wires and sites of insertion. This study aims to critically compare the biomechanical stability of different K-wire fixation techniques. Different osteosyntheses were reconstructed on 189 novel standardized bone models, which were created using 3D printing and molding techniques, using PLA and polyurethane materials, and it has been characterized in terms of mechanical behavior and structure. X-ray imaging has also been performed. The validation of the model was successful: the relative standard deviations (RSD = 100 × SD × mean−1, where RSD is relative s...

Additive manufacturing technologies based on metal melting use materials mainly in powder or wire form. This study focuses on developing a metal 3D printing process based on cold metal transfer (CMT) welding technology, in order to achieve enhanced productivity. Aluminium alloy test specimens have been fabricated using a special 3D printing technology. The probes were investigated to find correlation between the welding parameters and geometric quality. Geometric measurements and tensile strength experiments were performed to determine the appropriate welding parameters for reliable printing. The tensile strength of the product does not differ significantly from the raw material. Above 60 mm height, the wall thickness is relatively constant due to the thermal balance of the welding environment. The results suggest that there might be a connection between the welding parameters and the printing accuracy. It is demonstrated that the deviation of ideal geometry will be the smallest at ...

Different additive manufacturing technologies have proven effective and useful in remote medicine and emergency or disaster situations. The coronavirus disease 2019 (COVID-19) disease, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) virus, has had a huge impact on our society, including in relation to the continuous supply of personal protective equipment (PPE). The aim of the study is to give a detailed overview of 3D-printed PPE devices and provide practical information regarding the manufacturing and further design process, as well as describing the potential risks of using them. Open-source models of a half-face mask, safety goggles, and a face-protecting shield are evaluated, considering production time, material usage, and cost. Estimations have been performed with fused filament fabrication (FFF) and selective laser sintering (SLS) technology, highlighting the material characteristics of polylactic acid (PLA), polyamide, and a two-compound silicone....

Additive manufacturing technologies are dynamically developing, strongly affecting almost all fields of industry and medicine. The appearance of electrically conductive polymers has had a great impact on the prototyping process of different electrical components in the case of upper limb prosthetic development. The widely used FFF 3D printing technology mainly uses PLA (polylactic acid) and ABS (acrylonitrile butadiene styrene) based composites, and despite their presence in the field, a detailed, critical characterization and comparison of them has not been performed yet. Our aim was to characterize two PLA and ABS based carbon composites in terms of electrical and mechanical behavior, and extend the observations with a structural and signal transfer analysis. The measurements were carried out by changing the different printing parameters, including layer resolution, printing orientation and infill density. To determine the mechanical properties, static and dynamic tests were condu...

Currently, 3D printing is an affordable technology for industry, healthcare, and individuals. Understanding the mechanical properties and thermoplastic behaviour of the composites is critical for the users. Our results give guidance for certain target groups including professionals in the field of additive manufacturing for biomedical components with in-depth characterisation of the examined commercially available ABS and PLA carbon-based composites. The study aimed to characterize these materials in terms of thermal behaviour and structure. The result of the heating-cooling loops is the thermal hysteresis effect of Ohmic resistance with its accommodation property in the temperature range of 20–84 °C for ESD-ABS and 20–72 °C for ESD-PLA. DSC-TGA measurements showed that the carbon content of the examined ESD samples is ~10–20% (m/m) and there is no significant difference in the thermodynamic behaviour of the basic ABS/PLA samples and their ESD compounds within the temperature range ...