28 results on '"Chen, May-Show"'
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2. Comparative analysis of the retention force and deformation of PEEK and PEKK removable partial denture clasps with different thicknesses and undercut depths
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Lee, Wei-Fang, Chen, May-Show, Peng, Tzu-Yu, Huang, Peng-Chien, Nikawa, Hiroki, and Peng, Pei-Wen
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- 2024
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3. Synthesis and Characterization of Sol–Gelled Barium Zirconate as Novel MTA Radiopacifiers.
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Lin, Hsiu-Na, Chen, May-Show, Chang, Pei-Jung, Lee, Yao-Chi, Chen, Chin-Yi, Chiou, Yuh-Jing, and Lin, Chung-Kwei
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BARIUM zirconate , *RADIOPACITY , *MINERAL aggregates , *SCANNING electron microscopy , *TENSILE strength , *SOL-gel processes - Abstract
Barium zirconate (BaZrO3, BZO), which exhibits superior mechanical, thermal, and chemical stability, has been widely used in many applications. In dentistry, BZO is used as a radiopacifier in mineral trioxide aggregates (MTAs) for endodontic filling applications. In the present study, BZO was prepared using the sol–gel process, followed by calcination at 700–1000 °C. The calcined BZO powders were investigated using X-ray diffraction and scanning electron microscopy. Thereafter, MTA-like cements with the addition of calcined BZO powder were evaluated to determine the optimal composition based on radiopacity, diametral tensile strength (DTS), and setting times. The experimental results showed that calcined BZO exhibited a majority BZO phase with minor zirconia crystals. The crystallinity, the percentage, and the average crystalline size of BZO increased with the increasing calcination temperature. The optimal MTA-like cement was obtained by adding 20% of the 700 °C-calcined BZO powder. The initial and final setting times were 25 and 32 min, respectively. They were significantly shorter than those (70 and 56 min, respectively) prepared with commercial BZO powder. It exhibited a radiopacity of 3.60 ± 0.22 mmAl and a DTS of 3.02 ± 0.18 MPa. After 28 days of simulated oral environment storage, the radiopacity and DTS decreased to 3.36 ± 0.53 mmAl and 2.84 ± 0.27 MPa, respectively. This suggests that 700 °C-calcined BZO powder has potential as a novel radiopacifier for MTAs. [ABSTRACT FROM AUTHOR]
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- 2024
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4. Effects of Calcination Temperature on the Synthesis of One-Pot Sol-Gelled Barium Titanate Powder and Its Performance as an Endodontic Radiopacifier.
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Chang, Pei-Jung, Chen, May-Show, Cheng, Chi-Han, Chiou, Yuh-Jing, Chen, Chin-Yi, Su, Cherng-Yuh, and Lin, Chung-Kwei
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BARIUM titanate , *TEMPERATURE effect , *MINERAL aggregates , *RADIOPACITY , *POWDERS , *ENDODONTICS , *TENSILE strength , *FERROELECTRIC polymers - Abstract
Barium titanate (BaTiO3, BTO), conventionally used for dielectric and ferroelectric applications, has been assessed for biomedical applications, such as its utilization as a radiopacifier in mineral trioxide aggregates (MTA) for endodontic treatment. In the present study, BTO powders were prepared using the sol-gel process, followed by calcination at 400–1100 °C. The X-ray diffraction technique was then used to examine the as-prepared powders to elucidate the effect of calcination on the phase composition and crystalline size of BTO. Calcined BTO powders were then used as radiopacifiers for MTA. MTA-like cements were investigated to determine the optimal calcination temperature based on the radiopacity and diametral tensile strength (DTS). The experimental results showed that the formation of BTO phase was observed after calcination at temperatures of 600 °C and above. The calcined powders were a mixture of BaTiO3 phase with residual BaCO3 and/or Ba2TiO4 phases. The performance of MTA-like cements with BTO addition increased with increasing calcination temperature up to 1000 °C. The radiopacity, however, decreased after 7 days of simulated oral environmental storage, whereas an increase in DTS was observed. Optimal MTA-like cement was obtained by adding 40 wt.% 1000 °C-calcined BTO powder, with its resulting radiopacity and DTS at 4.83 ± 0.61 mmAl and 2.86 ± 0.33 MPa, respectively. After 7 days, the radiopacity decreased slightly to 4.69 ± 0.51 mmAl, accompanied by an increase in DTS to 3.13 ± 0.70 MPa. The optimal cement was biocompatible and verified using MG 63 and L929 cell lines, which exhibited cell viability higher than 95%. [ABSTRACT FROM AUTHOR]
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- 2024
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5. Radiopacity performances of precipitated ZrO2-doped Bi2O3 powders and the influences of dopant concentrations and sintering temperatures
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Chen, May-Show, Yang, Jen-Chang, Lai, Fu-Chih, Chen, Chin-Yi, Hsieh, Ming-Yang, Fang, Alex, Chen, Shih-Hsun, and Lin, Chung-Kwei
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- 2017
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6. Evaluation of the root and canal systems of maxillary molars in Taiwanese patients: A cone beam computed tomography study
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Lin, Yu-Hua, Lin, Hsiu-Na, Chen, Chien-Chih, and Chen, May-Show
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- 2017
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7. Preparation and characterization of silver nanocrystals decorated mesoporous bioactive glass via synchrotron X-ray reduction
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Fan, Fang-Yu, Chen, May-Show, Wang, Chia-Wei, Shih, Shao-Ju, Chen, Chin-Yi, Pan, Yung-Ning, and Lin, Chung-Kwei
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- 2016
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8. RECONSTRUCTIVE THERAPY OF PERI‑IMPLANTITIS, COMPARED TO RESECTIVE INTERVENTION, MAY RESULT IN LESS PERI‑IMPLANT MUCOSAL RECESSION
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Wang, Chin-Wei, Wu, Chia-Yu, and Chen, May-Show
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- 2023
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9. Endodontic Radiopacifying Application of Barium Titanate Prepared through a Combination of Mechanical Milling and Heat Treatment.
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Lin, Hsiu-Na, Chen, Wei-Wen, Hsu, Chun-Chun, Chen, May-Show, Chang, Pei-Jung, Chang, Wei-Min, Zhang, Fang-Hao, Chen, Chin-Yi, Lee, Pee-Yew, and Lin, Chung-Kwei
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MECHANICAL heat treatment ,BARIUM titanate ,POWDERS ,DENTAL discoloration ,FILLER materials ,RADIOPACITY ,MINERAL aggregates - Abstract
Mineral trioxide aggregates (MTA) are commonly used as endodontic filling materials but suffer from a long setting time and tooth discoloration. In the present study, the feasibility of using barium titanate (BTO) for discoloration and a calcium chloride (CaCl
2 ) solution to shorten the setting time was investigated. BTO powder was prepared using high-energy ball milling for 3 h, followed by sintering at 700–1300 °C for 2 h. X-ray diffraction was used to examine the crystallinity and crystalline size of the as-milled and heat-treated powders. MTA-like cements were then prepared using 20–40 wt.% BTO as a radiopacifier and solidified using a 0–30% CaCl2 solution. The corresponding radiopacity, diametral tensile strength (DTS), initial and final setting times, and discoloration performance were examined. The experimental results showed that for the BTO powder prepared using a combination of mechanical milling and heat treatment, the crystallinity and crystalline size increased with the increasing sintering temperature. The BTO sintered at 1300 °C (i.e., BTO-13) exhibited the best radiopacity and DTS. The MTA-like cement supplemented with 30% BTO-13 and solidified with a 10% CaCl2 solution exhibited a radiopacity of 3.68 ± 0.24 mmAl and a DTS of 2.54 ± 0.28 MPa, respectively. In the accelerated discoloration examination using UV irradiation, the color difference was less than 1.6 and significantly lower than the clinically perceptible level (3.7). This novel MTA exhibiting a superior color stability, shortened setting time, and excellent biocompatibility has potential for use in endodontic applications. [ABSTRACT FROM AUTHOR]- Published
- 2023
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10. Effects of C and Cr content on high-temperature microstructures of Fe–9Al–30Mn– xC– yCr alloys
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Chen, May-Show, Cheng, Hsin-Chung, Huang, Chiung-Fang, Chao, Chih-Yeh, Ou, Keng-Liang, and Yu, Chih-Hua
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- 2010
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11. Discoloration Improvement by Mechanically-Milled Binary Oxides as Radiopacifier for Mineral Trioxide Aggregates.
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Lin, Hsiu-Na, Wang, Ling-Chi, Chen, May-Show, Chang, Pei-Jung, Lin, Pin-Yu, Fang, Alex, Chen, Chin-Yi, Lee, Pee-Yew, and Lin, Chung-Kwei
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MINERAL aggregates ,OXIDE minerals ,TANTALUM compounds ,DENTAL discoloration ,TANTALUM oxide ,BISMUTH trioxide - Abstract
Mineral trioxide aggregates (MTA) have been widely used in endodontic treatments, but after some time, patients suffer tooth discoloration due to the use of bismuth oxide (Bi
2 O3 ) as a radiopacifier. Replacement of Bi2 O3 with high energy ball-milled single (zirconia ZrO2 ; hafnia, HfO2 ; or tantalum pentoxide, Ta2 O5 ) or binary oxide powder was attempted, and corresponding discoloration improvement was investigated in the present study. Bi2 O3 -free MTA is expected to exhibit superior discoloration. The radiopacity, diametral tensile strength, and discoloration of MTA-like cements prepared from the as-milled powder were investigated. Experimental results showed that MTA-like cements prepared using Ta2 O5 exhibited a slightly higher radiopacity than that of HfO2 but had a much higher radiopacity than ZrO2 . Milling treatment (30 min to 3 h) did not affect the radiopacities significantly. These MTA-like cements exhibited superior color stability (all measured ΔE00 < 1.0) without any perceptible differences after UV irradiation. MTA-like cements prepared using ZrO2 exhibited the best color stability but the lowest radiopacity, which can be improved by introducing binary oxide. Among the investigated samples, MTA-like cement using (ZrO2 )50 (Ta2 O5 )50 exhibited excellent color stability and the best overall performance with a radiopacity of 3.25 mmAl and a diametral tensile strength of 4.39 MPa. [ABSTRACT FROM AUTHOR]- Published
- 2022
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12. Multidisciplinary Approach for Full-Mouth Rehabilitation of a Young Adult Patient with Ameloblastoma
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Liao, Hung-Yi, Chen, May-Show, Yang, Ya-Fen, Liao, Pei-Bang, Feng, Sheng-Wei, and Juan, Po-kai
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stomatognathic diseases ,stomatognathic system ,Article Subject - Abstract
Ameloblastoma is a benign but locally invasive neoplasm of the odontogenic epithelium that tends to grow slowly in the mandible or maxilla. It can be highly destructive to the surrounding dental anatomy and can cause death by progressive spread to nearby vital structures in rare cases. Marginal resection is the most effective method of eliminating the tumor, but treatment can further contribute to oral and dental deformity and malfunction. This clinical report describes the dental rehabilitation of a young adult patient diagnosed with ameloblastoma and underwent preliminary marsupialization, segmental mandibulectomy, and fibula free flap reconstruction, followed by mandibular dental implant placements. Orthodontic and rapid palatal expansion for maxillary arch correction was also performed. The treatment goal of regaining dental function and a satisfactory appearance was accomplished.
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- 2021
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13. A Novel Sol-Gel Bi 2-x HfxO 3+x/2 Radiopacifier for Mineral Trioxide Aggregates (MTA) as Dental Filling Materials.
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Yang, Tzu-Sen, Chen, May-Show, Huang, Cheng-Jyun, Chen, Chin-Yi, Brangule, Agnese, Zarkov, Aleksej, Kareiva, Aivaras, Lin, Chung-Kwei, and Yang, Jen-Chang
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FILLER materials ,MINERAL aggregates ,DENTAL fillings ,RADIOPACITY ,DENTAL materials ,CALCIUM sulfate ,TRANSMISSION electron microscopy - Abstract
Mineral trioxide aggregate (MTA) is well known as an effective root canal filling material for endodontics therapy. Within MTA, bismuth oxide (Bi
2 O3 ) serving as the radiopacifier still has biocompatibility concerns due to its mild cytotoxicity. In the present study, we tried to modify the Bi2 O3 radiopacifier by doping hafnium ions via the sol-gel process and investigated the effects of different doping ratios (Bi2-x Hfx O3+x/2 , x = 0–0.3) and calcination temperatures (400–800 °C). We mixed various precursor mixtures of bismuth nitrate (Bi(NO3 )3 ·5H2 O) and hafnium sulfate (Hf(SO4 )2 ) and controlled the calcination temperatures. The as-prepared Hf-doped Bi2 O3 radiopacifier powders were investigated by thermogravimetric analysis (TGA), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). Portland cement/radiopacifier/calcium sulfate (75/20/5) were mixed and set by deionized water (powder to water ratio = 3:1). Changes in radiopacity, diametral tensile strength (DTS), and in vitro cell viability of the hydrated MTA-like cement were carried out. The experimental results showed that the group containing radiopacifier from sol-gelled Bi/Hf (90/10) exhibited significantly higher radiopacity (6.36 ± 0.34 mmAl), DTS (2.54 ± 0.29 MPa), and cell viability (84.0±8.1%) (p < 0.05) when compared to that of Bi/Hf (100/0) powders. It is suggested that the formation of β-Bi7.78 Hf0.22 O12.11 phase with hafnium addition and calcining at 700 °C can prepare novel bismuth/hafnium composite powder that can be used as an alternative radiopacifier for root canal filling materials. [ABSTRACT FROM AUTHOR]- Published
- 2021
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14. An Innovative Bioceramic Bone Graft Substitute for Bone Defect Treatment: In Vivo Evaluation of Bone Healing.
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Syam, Syamsiah, Cho, Yung-Chieh, Liu, Chung-Ming, Huang, Mao-Suan, Lan, Wen-Chien, Huang, Bai-Hung, Ueno, Takaaki, Tsai, Chi-Hsun, Saito, Takashi, Chen, May-Show, and Ou, Keng-Liang
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BONE regeneration ,BONES ,BONE substitutes ,BONE grafting ,FIELD emission electron microscopes ,MAXILLA ,HEALING - Abstract
This study aimed to analyze characteristics of an innovative α-calcium sulfate hemihydrate (α-CSH) bioceramic and bone healing and regeneration characteristics following its implantation on artificially created defects of rat models and human jaw defects. The α-CSH bioceramic was characterized using field emission scanning electron microscope (FE-SEM), energy-dispersive spectroscopy (EDS), and thermal-imaging instruments. The material was implanted on artificially created defects in a rat's right hind leg bone and observed histologically after three days and seven weeks. The material was also implanted in patients with bone defects in the posterior maxillary, then observed immediately and six months post-treatment by panoramic and computed tomography image. The FE-SEM confirm this material is a uniform-shaped short column crystal, while the EDS measurement reveals calcium as the most component in this material. Thermal observation shows temperature change during the setting time is less than 2 °C, and the maximum temperature reached is 31 °C. In the histological analysis, α-CSH bioceramic shows new trabecular bone formation and absorbed material at seven weeks post-treatment. Moreover, panoramic and computed tomography image shows intact bone six months post-treatment. Therefore, this study suggests that the innovative α-CSH bioceramic can be useful in bone defect treatment. [ABSTRACT FROM AUTHOR]
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- 2020
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15. Enhanced Diffusion Bonding Between High Purity Aluminum and 6061 Aluminum by Electrolytic Polishing Assistance
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Chen, May-Show, Fan, Fang-Yu, Lin, Chung-Kwei, and Chen, Chien-Chon
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- 2016
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16. The potential of the stem cells composite hydrogel wound dressings for promoting wound healing and skin regeneration: In vitro and in vivo evaluation.
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Hsu, Ling‐Chuan, Peng, Bou‐Yue, Chen, May‐Show, Thalib, Bahruddin, Ruslin, Muhammad, Tung, Tran Dang Xuan, Chou, Hsin‐Hua, and Ou, Keng‐Liang
- Abstract
In this study, the wound healing properties of the gelatin‐based hydrogel (GBH) wound dressing combined with adipose‐derived stem cells (ADSCs) were investigated using the mouse and porcine models. The analytical results showed that the ADSCs harvested from the porcine significantly increased cell growth and promoted cell differentiation (adipogenesis and osteogenesis) in comparison to the ADSCs harvested from the mouse in vitro. Moreover, the in vivo results also indicated that the GBH wound dressing combined with ADSCs and its culture medium could potentially accelerate wound healing in the mouse and porcine models. The ADSCs presented a possibility of recovery from wounds and injuries through skin regeneration. Therefore, both in vitro and in vivo results demonstrated that the ADSCs can potentially be an effective clinical treatment through the GBH wound dressing, which is a promising evidence‐based complementary and alternative medicine for skin regeneration. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 278–285, 2019. [ABSTRACT FROM AUTHOR]
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- 2019
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17. Dental Implant Surrounding Marginal Bone Level Evaluation: Platform Switching versus Platform Matching—One-Year Retrospective Study.
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Salamanca, Eisner, Lin, Jerry C.-Y., Tsai, Chi-Yang, Hsu, Yung-Szu, Huang, Haw-Ming, Teng, Nai-Chia, Wang, Peter D., Feng, Sheng-Wei, Chen, May-Show, and Chang, Wei-Jen
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DENTAL implants ,COMPARATIVE studies ,PROSTHODONTICS ,TIME ,RETROSPECTIVE studies - Abstract
The benefits and feasibility of platform switching have been discussed in several studies, reporting lesser crestal bone loss in platform-switched implants than in platform-matched implants. Objective. The aim of the present study was to observe the changes in vertical and horizontal marginal bone levels in platform-switched and platform-matched dental implants. Materials and Methods. 51 patients received 60 dental implants in the present study over a 1-year period. Measurement was performed between the implant shoulder and the most apical and horizontal marginal defect by periapical radiographs to examine the changes of peri-implant alveolar bone before and 12 months after prosthodontic restoration delivery. Results. These marginal bone measurements showed a bone gain of 0.23±0.58 mm in the vertical gap and 0.22±0.53 mm in the horizontal gap of platform matching, while in platform switching a bone gain of 0.93±1 mm (P<0.05) in the vertical gap and 0.50±0.56 mm in the horizontal gap was found. The average vertical gap reduction from the baseline until 12 months was 0.92±1.11 mm in platform switching and 0.29±0.85 mm in platform matching (P<0.05). Conclusions. Within the limitations of the present study, platform switching seemed to be more effective for a better peri-implant alveolar bone vertical and horizontal gap reduction at 1 year. [ABSTRACT FROM AUTHOR]
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- 2017
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18. Influence of Deformation and Stress between Bone and Implant from Various Bite Forces by Numerical Simulation Analysis.
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Cheng, Hsin-Chung, Peng, Boe-Yu, Chen, May-Show, Huang, Chiung-Fang, Lin, Yi, and Shen, Yung-Kang
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BONE physiology ,DENTAL implants ,TEETH abnormalities ,COMPUTED tomography ,DENTAL care ,HUMAN anatomical models ,MASTICATORY muscles ,DENTAL occlusion ,ORTHODONTICS ,TECHNOLOGY ,THREE-dimensional imaging ,DATA analysis software ,DIAGNOSIS - Abstract
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) methods. A numerical simulation of deformation and stress distributions around implants was used to estimate the survival life for implants. The model was applied to determine the pattern and distribution of deformations and stresses within the endosseous implant and on supporting tissues when the endosseous implant is used for orthodontic anchorage. A threaded implant was placed in an edentulous segment of a human mandible with cortical and cancellous bone. Analytical results demonstrate that maximum stresses were always located around the implant neck in marginal bone. The results also reveal that the stress for oblique force has the maximum value followed by the horizontal force; the vertical force causes the stress to have the minimum value between implant and bone. Thus, this area should be preserved clinically to maintain the structure and function of a bone implant. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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19. Single-molecule manipulation and detection platform for studying cancer cell chemotaxis.
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Chen, May-Show, Peng, Pei-Wen, Liou, Bing-Chun, Kuo, Hsiao-Chen, Ou, Keng-Liang, and Yang, Tzu-Sen
- Abstract
Chemotaxis of cancer cells is an essential component of tumor dissemination. The chemotactic response is comprised of three separate steps, including chemosensing, polarization and locomotion. We present an innovative approach on chemotaxis assay to address cancer cell chemotaxis. We applied a high-resolution optical tweezers system to manipulate epidermal growth factor (EGF)-coated beads positioned close to the filopodia, to locally stimulate HT29 cells expressing the EGF receptor (EGFR). We demonstrated that membrane protrusion at the leading edge induced by an EGF chemotaxis occurred at about 30∼40 s. In addition, the present observation revealed that the locomotion of HT29 cell depended on whether the HT29 cell sensed the presence of the chemoattractant EGF. We anticipate the proposed approach based on optical tweezers, together with the platform at single-cell level, could be applied to build a quick screening method for detection and treatment evaluation of many types of cancer during chemotaxis. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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20. Effect of heat treatment on the microstructures and damping properties of biomedical Mg–Zr alloy
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Tsai, Ming-Hung, Chen, May-Show, Lin, Ling-Hung, Lin, Ming-Hong, Wu, Ching-Zong, Ou, Keng-Liang, and Yu, Chih-Hua
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HEAT treatment of metals , *MICROSTRUCTURE , *DAMPING (Mechanics) , *MAGNESIUM alloys , *TRANSMISSION electron microscopy , *PHASE transitions , *SOLID solutions , *BIOMEDICAL materials - Abstract
Abstract: In this study, we elucidated the effect of heat treatment on the microstructures and damping properties of the biomedical Mg–1wt% Zr (K1) alloy by optical microscopy, transmission electron microscopy, energy-dispersive X-ray spectrometry, and experimental model analysis. The following microstructural transformation occurred when the as-quenched (AQ, i.e., solution heat treated and quenched) K1 alloy was subjected to aging treatment in the temperature range 200–500°C: α-Mg→(α-Mg+twindense)→(α-Mg+twinloose)→(α-Mg+α-Zr). This microstructural transformation was accompanied by variations in the damping capacity. The damping properties of the AQ K1 alloy subjected to aging treatment at 300°C for 16h were the best among those of the alloys investigated in the present study. The presence of twin structures in the alloy matrix was thought to play a crucial role in increasing the damping capacity of the K1 alloy. Hence, we state that a combination of solution treatment and aging is an effective means of improving the damping capacity of biomedical K1 alloys. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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21. Three-Dimensional Printing of a Hybrid Bioceramic and Biopolymer Porous Scaffold for Promoting Bone Regeneration Potential.
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Hung, Kuo-Sheng, Chen, May-Show, Lan, Wen-Chien, Cho, Yung-Chieh, Saito, Takashi, Huang, Bai-Hung, Tsai, Hsin-Yu, Hsieh, Chia-Chien, Ou, Keng-Liang, and Lin, Hung-Yang
- Subjects
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BONE regeneration , *THREE-dimensional printing , *BONE growth , *CALCIUM phosphate , *COMPRESSIVE force , *BIOPOLYMERS , *ATTACHMENT behavior , *SCANNING electron microscopy - Abstract
In this study, we proposed a three-dimensional (3D) printed porous (termed as 3DPP) scaffold composed of bioceramic (beta-tricalcium phosphate (β-TCP)) and thermoreversible biopolymer (pluronic F-127 (PF127)) that may provide bone tissue ingrowth and loading support for bone defect treatment. The investigated scaffolds were printed in three different ranges of pore sizes for comparison (3DPP-1: 150–200 μm, 3DPP-2: 250–300 μm, and 3DPP-3: 300–350 μm). The material properties and biocompatibility of the 3DPP scaffolds were characterized using scanning electron microscopy, X-ray diffractometry, contact angle goniometry, compression testing, and cell viability assay. In addition, micro-computed tomography was applied to investigate bone regeneration behavior of the 3DPP scaffolds in the mini-pig model. Analytical results showed that the 3DPP scaffolds exhibited well-defined porosity, excellent microstructural interconnectivity, and acceptable wettability (θ < 90°). Among all groups, the 3DPP-1 possessed a significantly highest compressive force 273 ± 20.8 Kgf (* p < 0.05). In vitro experiment results also revealed good cell viability and cell attachment behavior in all 3DPP scaffolds. Furthermore, the 3DPP-3 scaffold showed a significantly higher percentage of bone formation volume than the 3DPP-1 scaffold at week 8 (* p < 0.05) and week 12 (* p < 0.05). Hence, the 3DPP scaffold composed of β-TCP and F-127 is a promising candidate to promote bone tissue ingrowth into the porous scaffold with decent biocompatibility. This scaffold particularly fabricated with a pore size of around 350 μm (i.e., 3DPP-3 scaffold) can provide proper loading support and promote bone regeneration in bone defects when applied in dental and orthopedic fields. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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22. Mesoporous Properties of Bioactive Glass Synthesized by Spray Pyrolysis with Various Polyethylene Glycol and Acid Additions.
- Author
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Peng, Tzu-Yu, Tsai, Pei-Yun, Chen, May-Show, Mine, Yuichi, Wu, Shan-Hua, Chen, Chin-Yi, Lin, Dan-Jae, Lin, Chung-Kwei, and Rosu, Dan
- Subjects
BIOACTIVE glasses ,PYROLYSIS ,MOLECULAR weights ,SURFACE area ,ACIDS ,POLYETHYLENE glycol - Abstract
Mesoporous bioactive glass (MBG) has a high specific surface area, promoting the reaction area, thereby improving the bioactivity; thus, MBG is currently gaining popularity in the biomaterial field. Spray pyrolysis (SP) is a one-pot process that has the advantages of shorter process time and better particle bioactivity, therefore, MBG was prepared by SP process with various polyethylene glycol (PEG, molecular weight ranged from 2000–12,000) and acid (HCl and CH
3 COOH) additions. In vitro bioactivity and mesoporous properties of the so-obtained MBG were investigated. The experimental results showed that all the MBG exhibited amorphous and mesoporous structure. Increasing the molecular weight of PEG can improve the mesoporous structure and bioactivity of MBG. Whereas optimized MBG was prepared with suitable concentration of PEG and CH3 COOH. In the present work, MBG synthesized via spray pyrolysis by adding 5 g of PEG with a molecular weight of 12,000 and 50 mL of CH3 COOH exhibited the best in vitro bioactivity and mesoporous structure. [ABSTRACT FROM AUTHOR]- Published
- 2021
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23. Impact of Zr-Doped Bi 2 O 3 Radiopacifier by Spray Pyrolysis on Mineral Trioxide Aggregate.
- Author
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Peng, Tzu-Yu, Chen, May-Show, Chen, Ya-Yi, Chen, Yao-Jui, Chen, Chin-Yi, Fang, Alex, Shao, Bo-Jiun, Chen, Min-Hua, and Lin, Chung-Kwei
- Subjects
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MINERAL aggregates , *BISMUTH , *PYROLYSIS , *BISMUTH trioxide , *MATERIALS analysis , *PARTICULATE matter - Abstract
Mineral trioxide aggregates (MTA) have been developed as a dental root repair material for a range of endodontics procedures. They contain a small amount of bismuth oxide (Bi2O3) as a radiopacifier to differentiate adjacent bone tissue on radiographs for endodontic surgery. However, the addition of Bi2O3 to MTA will increase porosity and lead to the deterioration of MTA's mechanical properties. Besides, Bi2O3 can also increase the setting time of MTA. To improve upon the undesirable effects caused by Bi2O3 additives, we used zirconium ions (Zr) to substitute the bismuth ions (Bi) in the Bi2O3 compound. Here we demonstrate a new composition of Zr-doped Bi2O3 using spray pyrolysis, a technique for producing fine solid particles. The results showed that Zr ions were doped into the Bi2O3 compound, resulting in the phase of Bi7.38Zr0.62O12.31. The results of materials analysis showed Bi2O3 with 15 mol % of Zr doping increased its radiopacity (5.16 ± 0.2 mm Al) and mechanical strength, compared to Bi2O3 and other ratios of Zr-doped Bi2O3. To our knowledge, this is the first study of fabrication and analysis of Zr-doped Bi2O3 radiopacifiers through the spray pyrolysis procedure. The study reveals that spray pyrolysis can be a new technique for preparing Zr-doped Bi2O3 radiopacifiers for future dental applications. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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24. Effect of Oxygen Concentration and Tantalum Addition on the Formation of High Temperature Bismuth Oxide Phase by Mechanochemical Reaction.
- Author
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Lin, Hsiu-Na, Chen, May-Show, Chang, Yu-Hsueh, Lee, Pee-Yew, and Lin, Chung-Kwei
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TANTALUM , *BISMUTH trioxide , *TANTALUM compounds , *MECHANICAL alloying , *HIGH temperatures , *DIFFERENTIAL scanning calorimetry , *OXYGEN - Abstract
High-temperature face-centered cubic bismuth oxide phase is a material of great interest given its unique properties. In the present study, α-Bi2O3 and tantalum powders were used as the starting powders for the formation of high-temperature bismuth oxide phase via mechanochemical synthesis by high energy ball milling. (Bi2O3)80(Ta)20 and (Bi2O3)95(Ta)5 in weight concentrations were milled in either an oxygen-free argon-filled glove box environment or an ambient atmosphere to investigate the effects of oxygen concentration and tantalum addition. The as-milled powders were examined using X-ray diffraction, scanning electron microscopy with energy-dispersive spectroscopy, and differential scanning calorimetry to reveal the structural evolution. The experimental results showed that for (Bi2O3)95(Ta)5 powder mixtures milled within the glove box, tantalum gradually reacted with the α-Bi2O3 phase and formed a β-Bi7.8Ta0.2O12.2 phase. For (Bi2O3)80(Ta)20 milled under the same conditions, Ta and α-Bi2O3 mechanochemically reacted to form δ-Bi3TaO7 and bismuth after 10 min of high energy ball milling, whereas milling (Bi2O3)80(Ta)20 under the ambient atmosphere with a much higher oxygen concentration accelerated the mechanochemical reaction to less than five minutes of milling and resulted in the formation of high-temperature δ-Bi3TaO7 phase. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
25. Sintering Temperature-Dependence on Radiopacity of Bi(2−x) ZrxO(3+x/2) Powders Prepared by Sol-Gel Process.
- Author
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Chen, May-Show, Chen, Shih-Hsun, Lai, Fu-Chih, Chen, Chin-Yi, Hsieh, Ming-Yuan, Chang, Wei-Jen, Yang, Jen-Chang, and Lin, Chung-Kwei
- Subjects
- *
SINTERING , *BISMUTH oxides , *BIOCOMPATIBILITY , *THERMOGRAVIMETRY , *DENTAL materials - Abstract
Bismuth oxide (Bi2O3) is an effective additive used to enhance radiography resolution for dental materials. However, there are potential concerns regarding its biocompatibility and connection to tissue discoloration. In the present study, we modified the radiopacity properties of Bi2O3 with zirconium oxide (ZrO2) using a sol-gel process and investigated the composition, as well as the effects of heat treatment temperature using Thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The harvested Bi2−xZrxO3+x/2 particles showed that the dominant phase transferred from α-Bi2O3 to β-Bi7.38Zr0.62O12.31 after a heat treatment of over 750 °C for 2 h. As the x values of Bi2−xZrxO3+x/2 increased from 0.2 to 1.0, more zirconium oxide precipitated onto the particle surface, thus enhancing the surface roughness of particles. For sol-gel Bi1.8Zr0.2O3.1 powders (x = 0.2), the radiopacity values became 4.90 ± 0.23 and 5.83 ± 0.22 mmAl after a heat treatment of 500 °C and 750 °C, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
26. In vitro study of optimal removable partial denture clasp design made from novel high-performance polyetherketoneketone.
- Author
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Peng PW, Chen MS, Peng TY, Huang PC, Nikawa H, and Lee WF
- Subjects
- Polymers, Denture Retention, Benzophenones, Materials Testing, In Vitro Techniques, Dental Stress Analysis, Denture, Partial, Removable, Computer-Aided Design, Dental Clasps, Denture Design methods, Ketones
- Abstract
Purpose: This study aimed to investigate the retentive force and deformation of double Akers' polyetherketoneketone (PEKK) clasps on removable partial dentures (RPDs) with varying designs and undercut depths., Methods: Thirty double Akers' PEKK clasps with two different widths and heights (Groups I and II) were fabricated using computer-aided design and computer-aided manufacturing (CAD/CAM). Each design was further subdivided (n = 5) into three undercut depths (0.25, 0.50, and 0.75 mm). The retentive force of the clasps was measured after 10 years of clinical use (15,000 insertion/removal cycles), and the deformation of the clasp tips was analyzed before and after cycling., Results: Clasps with 0.50-mm and 0.75-mm undercut depths exhibited greater initial retentive forces (3.15-3.51 N) compared to those in the 0.25-mm undercut group (2.40-2.80 N). Group I maintained consistent retentive forces over the cycles (P = 0.345), whereas Group II showed declining forces after the initial use (P < 0.003). In both groups, the 0.50-mm undercut exhibited a greater retentive force than the 0.25-mm (P < 0.001 and P < 0.004, respectively), with no significant differences between the 0.50-mm and 0.75-mm undercut depths. Despite a lower initial retentive force, the 0.25-mm undercut showed less deformation and clasp tip wear., Conclusions: The PEKK clasps did not exhibit significantly reduced retentive forces or permanent deformations after 15,000 fatigue cycles. These results suggest that the PEKK polymer displays superior mechanical properties as an esthetic clasp material, and clasps with 0.50-mm and 0.75-mm undercut depths are recommended for long-term clinical use.
- Published
- 2024
- Full Text
- View/download PDF
27. Effects of Milling Time, Zirconia Addition, and Storage Environment on the Radiopacity Performance of Mechanically Milled Bi 2 O 3 /ZrO 2 Composite Powders.
- Author
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Chen MS, Lin HN, Cheng YC, Fang A, Chen CY, Lee PY, and Lin CK
- Abstract
Mineral trioxide aggregate (MTA) typically consists of Portland cement (75 wt.%), bismuth oxide (20 wt.%), and gypsum (5 wt.%) and is commonly used as endodontic cement. Bismuth oxide serving as the radiopacifying material reveals the canal filling effect after clinical treatment. In the present study, bismuth/zirconium oxide composite powder was prepared by high energy ball milling of (Bi
2 O3 )100 - x (x = 5, 10, 15, and 20 wt.%) powder mixture and used as the radiopacifiers within MTA. The crystalline phases of the as-milled powders were examined by the X-ray diffraction technique. The radiopacities of MTA-like cements prepared by using as-milled composite powders (at various milling stages or different amount of zirconia addition) were examined. In addition, the stability of the as-milled powders stored in an ambient environment, an electronic dry box, or a glove box was investigated. The experimental results show that the as-milled powder exhibited the starting powder phases of Bi2 )x (x = 5, 10, 15, and 20 wt.%) powder mixture and used as the radiopacifiers within MTA. The crystalline phases of the as-milled powders were examined by the X-ray diffraction technique. The radiopacities of MTA-like cements prepared by using as-milled composite powders (at various milling stages or different amount of zirconia addition) were examined. In addition, the stability of the as-milled powders stored in an ambient environment, an electronic dry box, or a glove box was investigated. The experimental results show that the as-milled powder exhibited the starting powder phases of Bi2 O3 and ZrO2 and the newly formed δ-Bi7.38 Zr0.62 O2.31 phase. The longer the milling time or the larger the amount of the zirconia addition, the higher the percentage of the δ-Bi7.38 Zr0.62 O2.31 phase in the composite powder. All the MTA-like cements prepared by the as-milled powder exhibited a radiopacity higher than 4 mmAl that is better than the 3 mmAl ISO standard requirement. The 30 min as-milled (Bi2 O3 )95 (ZrO2 )5 composite powder exhibited a radiopacity of 5.82 ± 0.33 mmAl and degraded significantly in the ambient environment. However, storing under an oxygen- and humidity-controlled glove box can prolong a high radiopacity performance. The radiopacity was 5.76 ± 0.08 mmAl after 28 days in a glove box that was statistically the same as the original composite powder., Competing Interests: The authors declare no conflict of interest.- Published
- 2020
- Full Text
- View/download PDF
28. Fabrication of device with poly(N-isopropylacrylamide)-b-ssDNA copolymer brush for resistivity study.
- Author
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Liu YZ, Chen MS, Cheng CC, Chen SH, and Chen JK
- Subjects
- DNA analysis, Electric Impedance, Fatty Acids, Unsaturated chemistry, Nucleic Acid Hybridization, Silicon chemistry, Acrylic Resins chemistry, DNA, Single-Stranded chemistry, Gold chemistry, Nanostructures chemistry
- Abstract
In this study, we grafted bromo-terminated poly(N-isopropylacrylamide) (PNIPAAm) brushes onto thin gold films deposited on silicon, and then reacted with NaN
3 to produce azido-terminated PNIPAAm brushes. A probe sequence of single-stranded DNA (ssDNA) with a 4-pentynoic acid succinimidyl ester unit was grafted onto the azido-terminated PNIPAAm brushes through a click reaction, resulting in the formation of block copolymer brushes. The PNIPAAm-b-ssDNA copolymer brushes formed supramolecular complexes stabilized by bio-multiple hydrogen bonds (BMHBs), which enhanced the proton transfer and thereby decreased the resistivity of the structures. In addition, the optimal operation window for DNA detection ranges from 0 to 0.2 M of NaCl concentration. Therefore, the specimens were prepared in the PBS solution at 150 mM NaCl concentration for target hybridization. The supramolecular complex state of the PNIPAAm-b-ssDNA copolymer brushes transformed into the phase-separated state after the hybridization with 0.5 ng/µL of its target DNA sequence owing to the competition between BMHBs and complementary hydrogen bonds. This phase transformation of the PNIPAAm and probe segments inhibited the proton transfer and significantly increased the resistivity at 25 °C. Moreover, there were no significant changes in the resistivity of the copolymer brushes after hybridization with the target sequence at 45 °C. These results indicated that the phase-separated state of the PNIPAAm-b-ssDNA copolymer brushes, which was generally occurred above the LCST, can be substantially generated after hybridization with its target DNA sequence. By performing the controlled experiments, in the same manner, using another sequence with lengths similar to that of the target sequence without complementarity. In addition, the sequences featuring various degrees of complementarity were exploited to verify the phase separation behavior inside the PNIPAAm-b-ssDNA copolymer thin film.- Published
- 2017
- Full Text
- View/download PDF
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