scholarly journals The influence of the post-processing method on knoop hardness of photosensitive resins for 3D SLA printer used in Dentistry

Author(s):  
Mayra Torres Vasques ◽  
Julia Nascimento Mulder ◽  
Debora Santos Machado ◽  
Dalva Cruz Lagana

Objectives: The aim of this study is to compare the mechanical characteristics of resins for 3D printers with the acrylic resins that have been used in Dentistry, according to the post-processing method. Materials and Methods: Using an SLA 3D printer (Form 2 – Formlabs, Massachusetts, USA), samples (discs) were produced with the printer’s resins, Dental SG®, Dental LT®, Clear®, and Grey®. Samples made of thermopolimerized and auto polymerized acrylic resins were produced as well (Gold Standart parameters). The Knoop Hardness (KH) tests were performed using microdurometer HMV-2 (Shimadzu, Kyoto, Japan). Results: The results showed the Dental SG resin presented the highest KH, compared with thermopolimerized acrylic resin, the Clear and Dental LT resins KH were compared with auto polymerized acrylic resin, and the non-post cured Grey resin (not for intraoral use), as well as the Dental LT resin, showed the lowest KH. Conclusions: Considering the hardness, the printer’s resins are comparable with the acrylic resins established, when the post-processing method is thoroughly followed. The absence of material’s post-processing reduce significantly the material’s hardness. Clinical relevance: Regarding the use of 3D printing in Dentistry, the development of materials adequate for the equipment, biocompatible for intraoral uses, and compatible mechanical proprieties are essential.

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2545
Author(s):  
Marcin Hoffmann ◽  
Krzysztof Żarkiewicz ◽  
Adam Zieliński ◽  
Szymon Skibicki ◽  
Łukasz Marchewka

Foundation piles that are made by concrete 3D printers constitute a new alternative way of founding buildings constructed using incremental technology. We are currently observing very rapid development of incremental technology for the construction industry. The systems that are used for 3D printing with the application of construction materials make it possible to form permanent formwork for strip foundations, construct load-bearing walls and partition walls, and prefabricate elements, such as stairs, lintels, and ceilings. 3D printing systems do not offer soil reinforcement by making piles. The paper presents the possibility of making concrete foundation piles in laboratory conditions using a concrete 3D printer. The paper shows the tools and procedure for pile pumping. An experiment for measuring pile bearing capacity is described and an example of a pile deployment model under a foundation is described. The results of the tests and analytical calculations have shown that the displacement piles demonstrate less settlement when compared to the analysed shallow foundation. The authors indicate that it is possible to replace the shallow foundation with a series of piles combined with a printed wall without locally widening it. This type of foundation can be used for the foundation of low-rise buildings, such as detached houses. Estimated calculations have shown that the possibility of making foundation piles by a 3D printer will reduce the cost of making foundations by shortening the time of execution of works and reducing the consumption of construction materials.


Author(s):  
Verma Walker, MLIS

Three-dimensional (3D) printing is opening new opportunities in biomedicine by enabling creative problem solving, faster prototyping of ideas, advances in tissue engineering, and customized patient solutions. The National Institutes of Health (NIH) Library purchased a Makerbot Replicator 2 3D printer to give scientists a chance to try out this technology. To launch the service, the library offered training, conducted a survey on service model preferences, and tracked usage and class attendance. 3D printing was very popular, with new lab equipment prototypes being the most common model type. Most survey respondents indicated they would use the service again and be willing to pay for models. There was high interest in training for 3D modeling, which has a steep learning curve. 3D printers also require significant care and repairs. NIH scientists are using 3D printing to improve their research, and it is opening new avenues for problem solving in labs. Several scientists found the 3D printer so helpful they bought one for their labs. Having a printer in a central and open location like a library can help scientists, doctors, and students learn how to use this technology in their work.


Author(s):  
Daniel A. Tillman ◽  
Ross C. Teller ◽  
Paul E. Perez ◽  
Song A. An

This chapter examines the theories, strategies, and techniques for employing 3D printing technologies to fabricate education-appropriate augmented reality (AR) headsets and provides a concrete example of an AR headset that the authors developed. The chapter begins by discussing theories and historically relevant events that provide a context for the chapter's narrative about use of 3D printers to support AR in education. Next, the chapter presents the strategies that were employed while developing and 3D fabricating a custom-designed AR headset that was intended for supporting middle school students learning science and mathematics content knowledge. Afterward, the chapter provides directions and resources for the reader describing how to build the presented AR headset design themselves by using a 3D printer and affordable electronic components, as well as information about how to join the Maker community and participate in the designing and producing of similar projects. Lastly, the chapter delivers a summarization of all findings discussed.


2017 ◽  
Vol 65 (1) ◽  
pp. 8-12
Author(s):  
Carmen Beatriz Borges FORTES ◽  
Fabrício Mezzomo COLLARES ◽  
Vicente Castelo Branco LEITUNE ◽  
Juliana Gehlen WALCHER ◽  
Stéfani Becker RODRIGUES ◽  
...  

ABSTRACT Objective: The aim of this study is to analyze if both color and nylon fibers have an influence on microwave-cured acrylic resin properties. Methods: Rectangular and disk-shaped specimens were prepared using acrylic resins; medium pink with and without nylon fibers and colorless without nylon fibers. To obtain the rectangular specimens, a stainless steel die was used with the following dimensions: 64 X 10 x 3 mm (± 0.5mm). To obtain disk-shaped specimens, a die 50mm (±0.5mm) in diameter and 0.5mm (±0.05mm) thick was employed. They were randomized to form groups: control (colorless acrylic) and experimental (medium pink, with and without nylon fibers), with each group consisting of ten (10) specimens rectangular in shape and five (5) disk-shaped. They were analyzed in six (6) assays (izod impact strength, n=10; Knoop hardness, n=10; glass transition temperature, n=3; water sorption and solubility, n=5; degree of monomer/polymer conversion, n=1; flexural strength and flexural modulus, n=10). All variables were subjected to the analysis of variance test followed by Tukey's multiple comparison test, at a 5% level of significance. Results: The analysis of the monomer/polymer degree of conversion did not reveal any difference between the three groups of resins (medium pink, with and without nylon fibers and colorless resin); it was approximately 88%. The results did not show significant differences between the groups for each variable (p>0.05). Conclusion: The results showed that color and presence of nylon fibers in acrylic resins did not affect the properties analyzed in this study.


Author(s):  
Vladimir Kuznetsov ◽  
Alexey Solonin ◽  
Oleg Urzhumtcev ◽  
Azamat Tavitov ◽  
Richard Schilling

The current paper is studying the influence of geometrical parameters of the FDM (FFF) 3D printing process on printed part strength for open source desktop 3D printers and the most popular material used for that purpose, i.e. PLA (polylactic acid). The study was conducted using a set of different nozzles (0.4, 0.6 and 0.8 mm) and a range of layer heights from the minimum to maximum physical limits of the machine. To assess print strength, a novel assessment method is proposed. A tubular sample is loaded in the weakest direction (across layers) in a three-point bending fixture. To explain the results obtained, a mesostructure evaluation through SEM scans of the samples were used. A significant influence of geometric process parameters was detected on sample mesostructure and, consequently, on sample strength.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2444 ◽  
Author(s):  
Paweł Turek ◽  
Grzegorz Budzik ◽  
Łukasz Przeszłowski

Nowadays, 3D printing technologies are among the rapidly developing technologies applied to manufacture even the most geometrically complex models, however no techniques dominate in the area of craniofacial applications. This study included 12 different anatomical structures of the mandible, which were obtained during the process of reconstructing data from the Siemens Somatom Sensation Open 40 system. The manufacturing process used for the 12 structures involved the use of 8 3D printers and 12 different polymer materials. Verification of the accuracy and radiological density was performed with the CT160Xi Benchtop tomography system. The most accurate results were obtained in the case of models manufactured using the following materials: E-Model (Standard Deviation (SD) = 0.145 mm), FullCure 830 (SD = 0.188 mm), VeroClear (SD = 0.128 mm), Digital ABS-Ivory (SD = 0.117 mm), and E-Partial (SD = 0.129 mm). In the case of radiological density, ABS-M30 was similar to spongious bone, PC-10 was similar to the liver, and Polylactic acid (PLA) and Polyethylene terephthalate (PET) were similar to the spleen. Acrylic resin materials were able to imitate the pancreas, kidney, brain, and heart. The presented results constitute valuable guidelines that may improve currently used radiological phantoms and may provide support to surgeons in the process of performing more precise treatments within the mandible area.


Author(s):  
Luiz Renato Rodrigues Carneiro ◽  
José Jean-Paul Zanlucchi de Souza Tavares

Nowadays 3D printing is a hot topic and this was specially observed during the COVID-19 pandemic. Hence, this project has the objective to present the design and implementation of a 3D printer, which fits the Mechanical Engineering Courses requisites. The founded solution follows the Delta architecture and it was called Delta MAPL. This paper will summarize all important definitions and knowledge to build a 3D printer such as, 3D printers technologies and architectures, expose the developed project involving mechanic and electric project, project cost, programming and slicer, calibration, printing parameters, and will also expose de results through implementation of the project, 3D printing tests, and also the documentation with all design parts, codes and printing parameters. Therefore, 3D printer is very useful and involving many fields of Mechanical Engineering knowledge, thus 3D printing develops not only knowledge in mechanic, electric, sensors and actuators and material properties, but also creativity and problem-solving that are so important for all engineering students.


2021 ◽  
Author(s):  
Vincent G. Colin ◽  
Théo A. Travers ◽  
Denis Gindre ◽  
Régis Barillé ◽  
Matthieu Loumaigne

Abstract The recent development of 3D printers allowed a lot of limitations in the field of microfabrication to be circumvented. The ever-growing chase for smaller dimensions has come to an end in domains such as microfluidics, and the focus now shifted to a cost-efficiency challenge. In this paper, the use of a high-resolution stereolithography LCD 3D printer is investigated for fast and cheap production of microfluidic master molds. More precisely, we use the UV LED array and the LCD matrix of the printer as an illuminator and a programmable photomask for soft lithography. The achieved resolution of around 100µm is mainly limited by the pixel geometry of the LCD matrix. A tree-shape gradient mixer was fabricated using the presented method. It shows very good performances despite the presence of sidewall ripples due to the uneven pixel geometry of the LCD matrix. Given its sub-€1,000 cost, this method is a very good entry point for labs wishing to explore the potential of microfluidic devices in their experiments, as well as a teaching tool for introducing students to microfluidics.


2018 ◽  
Vol 66 (3) ◽  
pp. 164-164 ◽  
Author(s):  
Susan A. Randolph

As the popularity of three-dimensional (3D) printers increases, more research will be conducted to evaluate the benefits and risks of this technology. Occupational health professionals should stay abreast of new recommendations to protect workers from exposure to 3D printer emissions.


2021 ◽  
Vol 16 ◽  
Author(s):  
Baocheng Xie ◽  
Shun Liu ◽  
Huaqiang Gao ◽  
Tingliang Zhang

Background: 3D printing technology is widely applied in transportation, industrial equipment, medical, aerospace, and civil industry due to its characteristics of material saving, no model manufacturing, and machinability of complex parts. The mechanical structure of 3D printer mainly includes 3D printer head structure and working platform and plays a major role in the machining efficiency and processing accuracy of the 3D printer. Thus, increasingly attention has been paid to the current trends of the mechanical structure of 3D printers. Objective: To meet the increasing requirements of 3D printing processing efficiency and precision, the mechanical structure of 3D printers, such as 3D print head structure and working platform, needs to be carefully studied, and a feasible mechanical structure of 3D printers should be proposed. Methods: This paper studies various representative patent related to the mechanical structure of 3D printer, analyzes the mechanical structure of 3D printer, and studies the perfect mechanical structure of 3D printer. Results: Through summarizing a lot of patents about the mechanical structure of 3D printers, the main current existing problems such as platform jitter and machining error are summarized and analyzed, a new mechanical structure of 3D printers is proposed. Moreover, the development tendency of the mechanical structure of 3D printers in the future is discussed. Conclusion: The optimization of the mechanical structure of 3D printer is conducive to increasing the machining efficiency and processing accuracy in the 3D printing process. More relevant patents about working platform and 3D printer head will be invented in the future


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