scholarly journals Bonding of conventional provisional resin to 3D printed resin: the role of surface treatments and type of repair resins

2020 ◽  
Vol 12 (5) ◽  
pp. 322
Author(s):  
Na-Kyung Lim ◽  
Soo-Yeon Shin
Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1643
Author(s):  
Ricardo Donate ◽  
María Elena Alemán-Domínguez ◽  
Mario Monzón

Surface modification of 3D-printed PLA structures is a major issue in terms of increasing the biofunctionality and expanding the tissue engineering applications of these parts. In this paper, different exposure times were used for low-pressure oxygen plasma applied to PLA 3D-printed scaffolds. Alkali surface treatments were also evaluated, aiming to compare the modifications introduced on the surface properties by each strategy. Surface-treated samples were characterized through the quantification of carboxyl groups, energy-dispersive X-ray spectroscopy, water contact angle measurements, and differential scanning calorimetry analysis. The change in the surface properties was studied over a two-week period. In addition, an enzymatic degradation analysis was carried out to evaluate the effect of the surface treatments on the degradation profile of the 3D structures. The physicochemical characterization results suggest different mechanism pathways for each type of treatment. Alkali-treated scaffolds showed a higher concentration of carboxyl groups on their surface, which enhanced the enzymatic degradation rate, but were also proven to be more aggressive towards 3D-printed structures. In contrast, the application of the plasma treatments led to an increased hydrophilicity of the PLA surface without affecting the bulk properties. However, the changes on the properties were less steady over time.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Sapam Ningthemba Singh ◽  
Vavilada Satya Swamy Venkatesh ◽  
Ashish Bhalchandra Deoghare

Purpose During the COVID-19 pandemic, the three-dimensional (3D) printing community is actively participating to address the supply chain gap of essential medical supplies such as face masks, face shields, door adapters, test swabs and ventilator valves. This paper aims to present a comprehensive study on the role of 3D printing during the coronavirus (COVID-19) pandemic, its safety and its challenges. Design/methodology/approach This review paper focuses on the applications of 3D printing in the fight against COVID-19 along with the safety and challenges associated with 3D printing to fight COVID-19. The literature presented in this paper is collected from the journal indexing engines including Scopus, Google Scholar, ResearchGate, PubMed, Web of Science, etc. The main keywords used for searches were 3D printing COVID-19, Safety of 3D printed parts, Sustainability of 3D printing, etc. Further possible iterations of the keywords were used to collect the literature. Findings The applications of 3D printing in the fight against COVID-19 are 3D printed face masks, shields, ventilator valves, test swabs, drug deliveries and hands-free door adapters. As most of these measures are implemented hastily, the safety and reliability of these parts often lacked approval. The safety concerns include the safety of the printed parts, operators and secondary personnel such as the workers in material preparation and transportation. The future challenges include sustainability of the process, long term supply chain, intellectual property and royalty-free models, etc. Originality/value This paper presents a comprehensive study on the applications of 3D printing in the fight against COVID-19 with emphasis on the safety and challenges in it.


Author(s):  
Nathalie Ramos ◽  
Christoph Mittermeier ◽  
Josef Kiendl

AbstractA good understanding of the heat transfer in fused filament fabrication is crucial for an accurate stress prediction and subsequently for repetitive, high-quality printing. This work focuses on two challenges that have been presented when it comes to the accuracy and efficiency in simulating the heat transfer in the fused filament fabrication process. With the prospect of choosing correct thermal boundary conditions expressing the natural convection between printed material and its environment, values for the convective heat transfer coefficient and ambient temperature were calibrated through numerical data fitting of experimental thermal measurements. Furthermore, modeling simplifications were proposed for an efficient numerical discretization of infill structures. Samples were printed with varying infill characteristics, such as varying air void size, infill densities and infill patterns. Thermal measurements were performed to investigate the role of these parameters on the heat transfer and based on these observations, possible modeling simplifications were studied in the numerical simulations.


2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Natanael Parningotan Agung ◽  
Muhammad Hanif Nadhif ◽  
Gampo Alam Irdam ◽  
Chaidir Arif Mochtar

Urology is one of the fields that are always at the frontline of bringing scientific advancements into clinical practice, including 3D printing (3DP). This study aims to discuss and presents the current role of 3D-printed phantoms and devices for organ-specified applications in urology. The discussion started with a literature search regarding the two mentionedtopics within PubMed, Embase, Scopus, and EBSCOhost databases. 3D-printed urological organ phantoms are reported for providing residents new insight regarding anatomical characteristics of organs, either normal or diseased, in a tangible manner. Furthermore, 3D-printed organ phantoms also helped urologists to prepare a pre-surgical planning strategy with detailed anatomical models of the diseased organs. In some centers, 3DP technology also contributed to developing specified devicesfor disease management. To date, urologists have been benefitted by 3D-printed phantoms and devices in the education and disease management of organs of in the genitourinary system, including kidney, bladder, prostate, ureter, urethra, penis, and adrenal. It is safe to say that 3DP technology can bring remarkable changes to daily urological practices.


2016 ◽  
Vol 2 (10) ◽  
pp. 1817-1826 ◽  
Author(s):  
Che-Ying Kuo ◽  
Avinash Eranki ◽  
Jesse K. Placone ◽  
Kelly R. Rhodes ◽  
Helim Aranda-Espinoza ◽  
...  

Author(s):  
Walker Jason ◽  
Bodamer Emily ◽  
Krebs Olivia ◽  
Luo Yuanyuan ◽  
Becker Matthew ◽  
...  

2021 ◽  
Author(s):  
Annalena Wieland ◽  
Pamela L. Strissel ◽  
Hannah Schorle ◽  
Ezgi Bakirci ◽  
Dieter Janzen ◽  
...  

Abstract Background: Glioblastoma multiforme (GBM) and triple-negative breast cancer (TNBC) with PTEN mutations often lead to brain dissemination with very poor patient outcomes. GBM uses axons and vessels as migratory cues to disseminate, however it is not known, if TNBC shares the same behavior. There is a need to understand brain tumor cell spreading and if GBM and TNBC have similar migration properties involving the signaling pathway RHOB-ROCK-PTEN. We tested for durotaxis, adherence and migration of GBM and TNBC using live-cell imaging and performed molecular analyses on three-dimensional (3D) structures.Methods: Aligned 3D printed scaffolds and microfibers were designed to mimic brain axon tracts and vessels for migration. GBM and TNBC cell lines, each with opposing PTEN genotypes, were analysed with RHO, ROCK and PTEN inhibitors and rescuing PTEN function using live-cell imaging. RNA-sequencing and qPCR of tumor cells in 3D with microfibers were performed, while SEM, confocal microscopy and cell tracking addressed cell morphology. Results: GBM and TNBC with homozygote PTEN loss of function and RHOB high expression were amoeboid shaped and demonstrated enhanced durotaxis, adhesion and migration on 3D microfibers, in contrast to PTEN wildtype GBM and TNBC showing elongated cells and low RHOB. RNA-sequencing exhibited that RHOB was significantly the highest expressed gene in GBM PTEN loss of function cells. Pathway inhibitors and PTEN rescue of function verified an essential role of RHOB-ROCK-PTEN signaling for durotaxis, adhesion, migration, cell morphology and plasticity using 3D printed microfibers. Conclusions: This study validates a significant role of a PTEN genotype for cellular properties including durotaxis, adhesion and migration. GBM and TNBC cells with PTEN loss of function have a greater affinity for stiffer brain structures promoting metastasis. We propose the significance of PTEN and RHOB in cellular oncology not only for primary tumors, but also for metastasizing tumors, where RHOB inhibitors could play an essential role for improved therapy.


2021 ◽  
Author(s):  
Tobias Butelmann ◽  
Hans Priks ◽  
Zoel Parent ◽  
Trevor G. Johnston ◽  
Tarmo Tamm ◽  
...  

AbstractThe three-dimensional printing of cells offers an attractive opportunity to design and develop innovative biotechnological applications, such as the fabrication of biosensors or modular bioreactors. Living materials (LMs) are cross-linked polymeric hydrogel matrices containing cells, and recently, one of the most deployed LMs consists of F127-bis-urethane methacrylate (F127-BUM). The material properties of F127-BUM allow reproducible 3D printing and stability of LMs in physiological environments. These materials are permissible for small molecules like glucose and ethanol. However, no information is available for oxygen, which is essential— for example, towards the development of aerobic bioprocesses using microbial cell factories. To address this challenge, we investigated the role of oxygen as a terminal electron acceptor in the budding yeast’s respiratory chain and determined its permissibility in LMs. We quantified the ability of cell-retaining LMs to utilize oxygen and compared it with cells in suspension culture. We found that the cells’ ability to consume oxygen was heavily impaired inside LMs, indicating that the metabolism mostly relied on fermentation instead of respiration. To demonstrate an application of these 3D printed LMs, we evaluated a comparative brewing process. The analysis showed a significantly higher (3.7%) ethanol production using 3D printed LMs than traditional brewing, indicating an efficient control of the metabolism. Towards molecular and systems biology studies using LMs, we developed a highly reliable method to isolate cells from LMs for flow cytometry and further purified macromolecules (proteins, RNA, and DNA). Our results show the application of F127-BUM-based LMs for microaerobic processes and envision the development of diverse bioprocesses using versatile LMs in the future.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Anna Aimar ◽  
Augusto Palermo ◽  
Bernardo Innocenti

Three-dimensional (3D) printing refers to a number of manufacturing technologies that generate a physical model from digital information. Medical 3D printing was once an ambitious pipe dream. However, time and investment made it real. Nowadays, the 3D printing technology represents a big opportunity to help pharmaceutical and medical companies to create more specific drugs, enabling a rapid production of medical implants, and changing the way that doctors and surgeons plan procedures. Patient-specific 3D-printed anatomical models are becoming increasingly useful tools in today’s practice of precision medicine and for personalized treatments. In the future, 3D-printed implantable organs will probably be available, reducing the waiting lists and increasing the number of lives saved. Additive manufacturing for healthcare is still very much a work in progress, but it is already applied in many different ways in medical field that, already reeling under immense pressure with regards to optimal performance and reduced costs, will stand to gain unprecedented benefits from this good-as-gold technology. The goal of this analysis is to demonstrate by a deep research of the 3D-printing applications in medical field the usefulness and drawbacks and how powerful technology it is.


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