Yung-Kang ShenTaipei Medical University | TMU · School of Dental Technology
Yung-Kang Shen
Doctor of Engineering
Chairman of School of Dental Technology
About
128
Publications
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Introduction
Skills and Expertise
Publications
Publications (128)
Introduction: Pore structure and geometry are crucial in scaffold development for tissue engineering. From this viewpoint, pore geometry characterization methods will aid in understanding the influence of pore structure (pore size and diffusivity) on its properties. These properties determine how oxygen and water enter the scaffold, forming adsorpt...
In this study, smart composite materials based on 4D printing technology were used to determine the grasping ability of four‐claw gripper of soft robot. First, fused deposition modeling (FDM) is used to prepare polylactic acid (PLA) strips on the surface of a rectangular bamboo substrate to create a single‐claw gripper for a smart composite soft ro...
Scaffolds are 3D biomaterials that provide an environment for cell regeneration. In the context of bone remodeling, poly(e-caprolactone) (PCL) combined with graphene has been developed as the scaffold. It is imperative for scaffolds to possess antibacterial properties in order to properly reduce the risk of potential infections.Therefore, this stud...
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 stre...
The present study aimed to investigate the surface characteristic, biocompatibility, and bone regeneration behavior of an innovative three-dimensional (3D) printed titanium (Ti) implant with a biomimetic cancellous bone-like spherical particle porous structure (3DBCP-Ti) through scanning electron microscopy, X-ray diffractometry, static contact ang...
In this study, polylactic acid (PLA) and thermoplastic polyurethane (TPU) were used to fabricate composite materials with different raster orientations by a 3D printing process. The idea of this study came from the fact that in nature, many plants have vertical or horizontal lines on their leaves or branches. The authors made use of the composite m...
The current digital dentistry workflow has streamlined dental restoration production, but the effectiveness of digital virtual design and 3D printing for restorations still needs evaluation. This study explores the impact of model-free digital design and 3D-printing placement angles on restorations, including single crowns and long bridges produced...
Objective Bacterial nanocellulose (BN), derived from Acetobacter xylinum ATCC 237672, is a polymer that offers several desirable characteristics for scaffolds applications. To further enhance the characteristic of the BN scaffold, hydroxyapatite (HAp) from Anadara granosa and Achatina fulica can be incorporated. Therefore, the aim of the study was...
Background/purpose
Producing tooth crowns through dental technology is a basic function of dentistry. The morphology of tooth crowns is the most important parameter for evaluating its acceptability. The procedures were divided into four steps: tooth collection, scanning skills, use of mathematical methods and software, and machine learning calculat...
The present study was conducted to manipulate various biomaterials to find potential hydrogel formulations through three-dimensional (3D) bioprinting fabrication for tissue repair, reconstruction , or regeneration. The hydrogels were prepared using sodium alginate and gelatin combined with different concentrations of Pluronic F127 (6% (3 g), 8% (4...
Head and neck squamous carcinoma (HNSCC) affects more than half a million individuals and ranks the ninth leading cause of death globally each year. Many patients develop treatment resistance leading to poor clinical outcomes. The poor treatment responses are in part due to the heterogeneity of HNSCC tumor and tumor microenvironment (TME). The inte...
This study aims to characterize the osteoconductivity, optimal bioresorbable, biodegradability, biocompatibility, and mechanical properties of Poly-ε-caprolactone (PCL)/graphene (G) scaffolds at concentrations of 0.5, 1, 1.5, 2, 2.5, and 3 wt%, which are used to support bone regeneration through solvent casting and particulate leaching. The water c...
The advancements in the cell culture studies have led to the development of regenerative medicine concept. The aim of this study is to compare the effectiveness of some washing solutions, including phosphate buffered saline (PBS), sodium chloride (NaCl), and ringer's lactate (RL) on the rate of detachment and confluency in fibroblast and osteoblast...
Hydrogen can be employed as an alternative renewable energy source in response to climate change, global warming, and the energy problem. Methanol gas steam reforming (SRM) is the major method used in industry to produce hydrogen. In the SRM process, the catalyst nature offers benefits such as low cost, simplicity, and quickness. In this work, dela...
The present study aimed to develop a highly pure and crystalline beta-tricalcium phosphate (β-TCP) bone graft substitute using the propagated Scleractinian coral. The solid-state reaction followed by heat-treatment (1050 °C ∼ 1100 °C for 1 h) between calcium carbonate from the propagated coral and dicalcium phosphate anhydrous was performed to fabr...
Objective Scaffolds provided a surface on which cells could attach, proliferate, and differentiate. Nowadays, bone tissue engineering offers hope for treating bone cancer. Poly(e-caprolactone) (PCL)/graphene have capability as an osteogenic and regenerative therapy. It could be used to produce bone tissue engineering scaffolds. The purpose of this...
Objective:
Despite apoptosis processes being conserved, cancer cells have developed mechanisms to inhibit apoptosis by altering anti-apoptotic molecules or inactivating pro-apoptotic. The aim of this study was to determine the palmitic acid of Musa paradisiaca var. sapientum (L) Kunz (MP) stem extracts against human oral squamous cell carcinoma (h...
BACKGROUND: Indonesia's tropical forest is home to around 80% of the world's medicinal plants. One of these is Zingiber purpureum, which have traditionally been used to treat joint discomfort, the common cold, and jaundice. The rhizomes of this plant have been suggested to possess antibacterial action in the treatment of infections. In this study,...
When the size of a liquid crystal display (LCD) increases, the light guiding plate (LGP) as the main part of the LCD must adopt a wedge-shaped plate to reduce its weight (the thickness of the LGP decreases because of this) and guide the light to the LCD screen. Micro-injection molding (MIM) is commonly used to manufacture LGPs. During the filling p...
The present study aimed to determine the effectiveness of Trigona spp. propolis as an antioxidant to reduce residual peroxide after intra-coronal bleaching treatments. Thirty-five maxillary central incisors were divided into seven groups: five samples without antioxidants; sodium ascorbate 10% combined with Tween 80 0.2%; and Trigona spp. propolis...
In this study, we determined the effects of design and processing parameters of precision injection molding (PIM) to minimize warpage phenomena of micro-sized parts using various plastics (polyoxymethylene (POM), acrylonitrile-butadiene-styrene (ABS), polypropylene (PP), polyamide (PA), and ABS+ polycarbonate (PC)). We applied a numerical simulatio...
In this study, we designed and fabricated transmission parts for a flapping-wing micro-aerial vehicle (FW-MAV), which was fabricated by precision injection molding, and analyzed its warpage phenomena. First, a numerical simulation (Moldflow) was used to analyze the runner balance and temperature, pressure, and stress distributions of the base, gear...
In this work, a novel set of methods is prοposed for tuning the oxygen vacancy distribution through the combination of several effects. More specifically, the incorporation of a Ti nano-island (NI), as well as the insertion of a thin layer of HfO2 with 10 nm thickness and the subsequent enforcement of an annealing step at 400 ℃ are employed to impr...
Objective Topical application of ambonese banana (Musa paradisiaca var. sapientum (L.) kuntze) stem sap gel (GEGPA) on the socket wound area showed an increase in the expression of platelet-derived growth factor-BB, while decrease in the expression of matrix metalloproteinase-2 and 9. The aim of this study is to achieve standard formulation of GEGP...
Background:
The ChAdOx1 nCoV-19 vaccine has been widely administered against SARS-CoV-2 infection; however, data regarding its immunogenicity, reactogenicity, and potential differences in responses among Asian populations remain scarce.
Methods:
270 participants without prior COVID-19 were enrolled to receive ChAdOx1 nCoV-19 vaccination with a p...
The ability of Pluronic F127 (PF127) conjugated with tetrapeptide Gly-Arg-Gly-Asp (GRGD) as a sequence of Arg-Gly-Asp (RGD) peptide to form the investigated potential hydrogel (hereafter referred to as 3DG bioformer (3BE)) to produce spheroid, biocompatibility, and cell invasion ability, was assessed in this study. The fibroblast cell line (NIH 3T3...
This study examined the uniformity of illuminance field distributions of light guide plates (LGPs). First, the authors designed microstructural patterns on the surface of an LGP. Then, a mold of the LGP with the optimal microstructural design was fabricated by a photolithography method. Micro-injection molding (μIM) was used to manufacture the mold...
Osteoporosis is characterized by increased bone fragility, and the drugs used at present to treat osteoporosis can cause adverse reactions. Gentiopicroside (GEN), a class of natural compounds with numerous biological activities such as anti-resorptive properties and protective effects against bone loss. Therefore, the aim of this work was to explor...
This study applied poly-ε-caprolactone (PCL), a biomedical ceramic powder as an additive (nano-hydroxyapatite (nHA) or β-tricalcium diphosphate (β-TCP)), and sodium chloride (NaCl) and ammonium bicarbonate ((NH4)HCO3) as porogens; these stuffs were used as scaffold materials. An improved solvent-casting/particulate-leaching method was utilized to f...
In these times of Industrial 4.0 and Health 4.0, people currently want to enhance the ability of science and technology, to focus on patient aspects. However, with intelligent, green energy and biomedicine these days, traditional three-dimensional (3D) printing technology has been unable to meet our needs, so 4D printing has now arisen. In this res...
This study replicated a molded plastic substrate with micropatterns by a mold insert employing ultrasonic hot embossing. A plastic substrate and mold insert were combined and heated above the plastic’s glass transition temperature, and then the softened plastic was allowed to flow into the micropattern of the mold insert making use of pressure appl...
This study emphasizes the warpage phenomenon of thin-walled parts using acrylonitrile-butadiene styrene (ABS) plus polycarbonate (PC) plastics for optimal processing by thin-wall injection molding. The authors first employed the Moldflow software to analyze the runner’s balance on multicavities for thin-walled parts and to simulate the warpage of t...
A mechanochemical effect is investigated to reduce diamond tool wear by means of applying a surfactant to low-carbon magnetic iron during diamond turning. Orthogonal microcutting demonstrates the manifestation of the mechanochemical effect through the reduction of cutting forces by 30%, which supports the notion of lower cutting temperatures for re...
Background: Osteoporosis is characterized by increased bone fragility and the drugs used at present to treat osteoporosis can cause adverse reactions. Gentiopicroside (GEN) is widely used in the traditional Chinese medicine thanks to its multiple pharmacological activities including the suppression of osteoclastogenesis. Therefore, the aim of this...
This research produced a microneedle array patch consisting of a biodegradable polymer. Due to guidelines for the material’s failure and the mechanical properties of various skin layers, this research investigates four types of microneedles of three sizes to determine the optimal microneedle. Through numerical simulation, the insertion force and va...
Background/purpose
In clinical operations, qualitative differences in the texture and operational feeling of the regular type and soft type back-filled gutta-percha are readily discernible. This study aimed to investigate and compare the thermal behavior and physical properties of the two gutta-percha materials.
Materials and methods
The chemical...
The surface of Ti6Al4V substrate was modified by two ways: micro-powder blasting and co-blast technique. Micro-powder blasting was done using Al2O3 (of three different sizes) or SiC particles. Co-blast technique was done using the same particles co-blasted with hydroxyapatite (HA) particles. The morphology, roughness, deep impact and contact angle...
A drug-eluting stent with rhombic-shaped drug reservoirs is proposed, aimed at providing long-term drug delivery and enhanced fatigue life. Unique rhombic-shaped reservoirs or channels on the stent struts can increase the total drug capacity and improve the stress distribution for longer fatigue life, without compromising other important clinical a...
This study investigates the results of cell cultures on aluminum (Al) templates with flat-structures, micro-structures, nano-structures and micro/nano-structures. An Al template with flat-structure was obtained by electrolytic polishing; an Al template with micro-structure was obtained by micro-powder blasting; an Al template with nano-structure wa...
Endosseous oral implant is applied for orthodontic anchorage in subjects with multiple tooth agenesis. Its effectiveness under orthodontic loading has been demonstrated clinically and experimentally. This study investigates the deformation and stress on the bone and implant for different bite forces by three-dimensional (3D) finite element (FE) met...
The conventional orthodontic power chain, often composed of polymer materials, has drawbacks such as a reduction of elasticity owing to water absorption as well as surface discoloration and staining resulting from food or beverages consumed by the patient. The goal of this study was to develop a surface treatment (nanoimprinting) for orthodontic po...
Nanoporous anodic aluminum oxide (AAO) templates are fabricated using an anodization method. The mean diameter of the nanoporous AAO templates is 100 nm. A molded plastic thin film with nanostructure is fabricated using AAO template as a mold insert by nanoimprint. The surface properties of the molded plastic thin film obtained using various proces...
Endosseous oral implants are used for orthodontic anchorage in subjects with multiple tooth agenesis. Their effectiveness under orthodontic loading has been demonstrated clinically and experimentally. This study examines three-dimensional (3D) finite element (FE) models for bone and implants. A numerical simulation of stress distributions around im...
A highly uniform and hydrophobic nanopillar film was fabricated by nanoimprinting using the AA0 template as a mold in this study. Nanoporous anodic aluminum oxide (AAO) templates are fabricated using an anodization method. The mean diameters of nanoporous anodic aluminum oxide templates are 100 nm and 200 nm by various processing parameters of the...
The naturally occurring isoprene rubber component of gutta-percha has been used in dental root canal filling treatments for almost a hundred years owing to its stability and plasticity as a root canal filling material. The traditional warm gutta-percha vertical compaction technique is the major technique for warm gutta-percha root canal obturation....
The traditional orthodontic power chain, usually made of polymer materials, exists some drawbacks, such as the reduction of elasticity due to swell after absorbing water and surface discoloration resulting from the patient’s diet, food, or beverage colors leading to poor appearance. The main purpose of this study was to develop surface modification...
Nanoporous anodic aluminum oxide (AAO) templates are fabricated using an nodization method. The mean diameters of nanoporous anodic aluminum oxide templates are 100 nm and 200 nm by various processing parameters of the anodization method. A molded plastic thin film nanostructure is fabricated by nanoimprinting using the AAO template as a mold inser...
This study indicates the micropattern of molded plastic film from a mold insert using ultrasonic micro embossing. A mold insert and plastic film are heated above the glass transition temperature of plastic, and the softened plastic is flowed into the micropattern of a mold insert by applying pressure via a conventional technique. A longitudinal ult...
This study determines the replication property and surface roughness of microfeatures of a Nimould that combines electroforming and large area hot embossing. The metal mould first uses a4 in. silicon wafer to fabricate a master using the UV-LIGA method, and then applies thesputtering method to sputter the copper element as the seed layer on the sur...
Three-dimensional porous biodegradable polymer scaffolds have been widely used for tissue engineering of bone repair or regeneration. The primary function of scaffolds is to provide structure support for the cells adhesion and proliferation. This study selects the Poly-ɛ-caprolactone (PCL) as material, NaCl mixed with hydroxyapatite (HA) or nano-al...
Hydroxyapatite (HA) coating of hard tissue implants is widely employed for its biocompatible and osteoconductive properties as well as its improved mechanical properties. In this study, a novel micro-blasting process has been used to successfully modify a titanium alloy substrate with a HA treatment using a dopant/abrasive regime. The impact of a s...
3D porous biodegradable polymer scaffolds have been used for tissue engineering of bone repair or regeneration. The primary function of scaffolds is to provide structure support for the cells adhesion and proliferation. This study uses the Poly-ε-caprolactone (PCL) as material,
NaCl mixed with hydroxyapatite (HA). This study uses the solution casti...
Porous scaffolds fabricated from biodegradable polymers have been widely used and play a vital role in tissue engineering and in situ tissue reconstruction. This study presents a novel fabrication technique involving injection molding and conventional particulate leaching (IM/PL) to obtain the L-shaped nasal scaffold for rhinoplasty. The results in...
This study photo-etches micropatterns on mold inserts and manufactures a light guide plate with microstructures using microinjection molding. The single parameter method is used to investigate flatness and replication with different process parameters for microinjection molding. Mold temperature is the most important factor for plate flatness and m...
Nanoporous anodic aluminum oxide (AAO) templates are fabricated using an anodization method. The mean diameters of nanoporous anodic aluminum oxide templates are 100 nm and 200 nm by various processing parameters of the anodization method. A molded plastic thin film nanostructure is fabricated by nanoimprinting using the AAO template as a mold. The...
In this paper, we are investigating the different cultured structures scale in micrometer and nanometer. The experiment have been fabricated four types aluminum substrate structures which included none-structure, micro-structure, nano-structure, and combined micro/nano structure to fulfill the research in osteoblast-like cell (MG 63). Finally we pe...
The purpose of this research is to find the optimal design for biodegradable polymer microneedle patches. Based on the mechanical properties of different skin layers and the failure criterion of the material, this research designs a microneedle of four types and three sizes, then discusses the insertion force and the variation of stress during the...
This study characterizes warpage of a micro-injection molded micro electrical fan using the Michelson interference method. This study conducts experiments to analyze different polymers-polypropylene (PP), polyamide (PA), acrylonitrile-butadiene styrene (ABS), ABS+ polycarbonate (PC), and polyoxymethylene (POM)-process parameters, such as mold tempe...
This study forms hydroxyapatite-silica ceramic structure, which can generate interconnected porous 3D models suitable as bone scaffold, using a novel selective laser sintering (SLS) technique. Hydroxyapatite (HA) powder and a silica sol are first mixed into slurries. After processing by SLS, the HA particles are embedded in the gelled silica matrix...
This study develops an improved method for generating aluminum mold inserts used in the replication of polymer-based microfluidic chip. Since molding masters that are suitable for microfluidic chip replication must have features whose dimensions are of the order of tens to hundreds of microns, micro electrical discharge machining is employed herein...
Nanoporous anodic aluminum oxide (AAO) templates are fabricated using an
anodization method. The mean diameter of the nanoporous anodic aluminum
oxide templates is 100 nm. A molded plastic thin film with
nano-structure is fabricated using AAO template as a mold insert by
nanoimprint. The surface properties of the molded plastic thin film
obtained u...
This study investigates warpage of electronic dictionary battery covers fabricated using thin-wall injection molding as a
replacement for conventional insert molding. The primary concern is the molding window in thin-wall injection molding for
acrylonitrile–butadiene styrene (ABS) and polycarbonate (PC)+ABS plastics. Finally, the process parameters...
This study fabricated a novel biodegradable polymer microneedle patch. First, a master microneedle array was fabricated using the micro electro-mechainal system (MEMS) process. Polydimethylsiloxane (PDMS) was then utilized to fabricate the microneedle mold. Finally, the biodegradable polymer polylactic acid (PLA) microneedle patch was fabricated by...
This study investigates the flow characteristics of microinjection-molded lightguiding plates. This study also analyzes the position of melt fronts on lightguiding plates. Viscous heating, temperature and velocity distribution are utilized to analyze delay or advancement of the melt front experimentally and using three-dimensional (3D) numerical si...
This work reports a novel and effective procedure for manufacturing the mold insert of microlens arrays. First, the microlens arrays master is formed using room-temperature imprint lithography and photoresist reflow process. Next, electroforming is carried out to fabriccate the metal mold insert from the master. Finally, microinjection molding is u...
This paper presents a layer manufacturing technology called selective laser gelation (SLG), combining selective laser sintering (SLS) and sol–gel technique, for fabricating ceramic–matrix composite green parts which are difficult to produce using conventional processes. The material used comprises stainless steel powder and a silica sol at a propor...
Nanoporous anodic aluminum oxide (AAO) templates are fabricated using an anodization method. The mean diameters of nanoporous anodic aluminum oxide templates are 100 nm and 200 nm by various processing parameters of the anodization method. A molded plastic thin film nanostructure is fabricated by nanoimprinting using the AAO template as a mold inse...
This study describes the brightness field distributions of microlens arrays fabricated by micro injection molding (μIM) and micro injection-compression molding (μICM). The process for fabricating microlens arrays used room-temperature imprint lithography, photoresist reflow, electroforming, μIM, μICM, and optical properties measurement. Analytical...
This paper proposes a solid freefrom fabrication (SFF) technology for fabricating hydroxyapatite(HA)-silica ceramics, which can generate porous three-dimensional physical objects. The HA powder and the silica are mixed with water into slurries form as raw materials. The slurries are paved by a scraper to from a thin layer which is selective scanned...
In this study, master of the microlens arrays is fabricated using micro dispensing technology, and then electroforming technology is employed to replicate the Ni mold insert of the microlens arrays. Finally, micro hot embossing is performed to replicate the molded microlens arrays from the Ni mold insert. The resin material is used as the dispensin...