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Dental Materials Journal Aug 2023Adhesion of the most common dental biofilm bacteria to alloys used in orthodontics in relation to surface characteristics was analyzed. Streptococcus mutans (S. mutans),...
Adhesion of the most common dental biofilm bacteria to alloys used in orthodontics in relation to surface characteristics was analyzed. Streptococcus mutans (S. mutans), Streptococcus oralis (S. oralis), Veillonella parvula (V. parvula), and Aggregatibacter actinomycetemcomitans (A. actynomicetemcomitans) were incubated for 4 h with nickel-titanium (NiTi) and stainless-steel (SS) wires. The surface roughness and free energy of the alloys, as well as the hydrophobicity of the alloys and bacteria, were assessed. NiTi had higher surface free energy and rougher (p<0.001) and more hydrophilic surfaces than SS (p<0.001). The hydrophobic properties of the bacteria decreased in the following order: V. parvula>S. oralis>S. mutans>A. actynomicetemcomitans. Bacterial adhesion generally increased over time, though this pattern was influenced by the type of alloy and the bacteria present (p<0.001). In a multiple linear regression, the principal predictor of adhesion was bacterial hydrophobicity (p<0.001), followed by time (p<0.001); alloy surface characteristics had a low influence.
Topics: Dental Alloys; Orthodontic Wires; Surface Properties; Orthodontic Appliances; Alloys; Streptococcus mutans; Titanium; Stainless Steel
PubMed: 37271541
DOI: 10.4012/dmj.2022-235 -
International Journal of Molecular... 2011This paper reviews the influence of alloying elements Mo, Nb, Ta and Ni on glass formation and corrosion resistance of Cu-based bulk metallic glasses (BMGs). In order to... (Review)
Review
This paper reviews the influence of alloying elements Mo, Nb, Ta and Ni on glass formation and corrosion resistance of Cu-based bulk metallic glasses (BMGs). In order to obtain basic knowledge for application to the industry, corrosion resistance of the Cu-Hf-Ti-(Mo, Nb, Ta, Ni) and Cu-Zr-Ag-Al-(Nb) bulk glassy alloy systems in various solutions are reported in this work. Moreover, X-ray photoelectron spectroscopy (XPS) analysis is performed to clarify the surface-related chemical characteristics of the alloy before and after immersion in the solutions; this has lead to a better understanding of the correlation between the surface composition and the corrosion resistance.
Topics: Alloys; Copper; Corrosion; Glass; Metals; Surface Properties
PubMed: 21731441
DOI: 10.3390/ijms12042275 -
Dental Materials Journal May 2022The cytocompatibility and osteoconductivity of the Zr-14Nb-5Ta-1Mo alloy were investigated using a mouse osteoblastic cell line (MC3T3-E1) to promote the application of...
The cytocompatibility and osteoconductivity of the Zr-14Nb-5Ta-1Mo alloy were investigated using a mouse osteoblastic cell line (MC3T3-E1) to promote the application of this newly developed alloy in dental/medical treatment. The initial cell-attached morphology was visualized by fluorescent staining, and cells cultured on the Zr alloy showed similar cell adhesion behavior to cells cultured on titanium (Ti). In our 5-day proliferation investigation, similar cell numbers were obtained with both Zr alloy and Ti. These results indicate that the cytocompatibility of Zr alloy is similar to that of Ti. In addition, the similar results in the evaluation of alkaline phosphatase (ALP) activity and staining of deposited calcium using alizarin red S with both Zr alloy and Ti indicated that the osteoconductivity of the Zr alloy is similar to that of Ti. Our results prove the good cytocompatibility and osteoconductivity of the Zr-14Nb-5Ta-1Mo alloy, enabling its promotion for use in dental/medical applications.
Topics: Alloys; Cell Adhesion; Osteoblasts; Titanium; Zirconium
PubMed: 35135939
DOI: 10.4012/dmj.2021-169 -
Annals of Work Exposures and Health Jul 2020Nickel (Ni) and cobalt (Co) release from chromium-alloy powders (different stainless steels and a nickel-based Inconel alloy) compared with Ni and Co metal powders was...
Nickel (Ni) and cobalt (Co) release from chromium-alloy powders (different stainless steels and a nickel-based Inconel alloy) compared with Ni and Co metal powders was investigated at simulated human exposure scenarios (ingestion, skin contact, and inhalation) between 2 and 168 h. All investigated powders consisted of particles sized within the respirable range. The powder particles and their surface reactivity were studied by means of nitrogen adsorption and electrochemical, spectroscopic (X-ray photoelectron spectroscopy and atomic absorption spectroscopy), light scattering, and microscopic techniques. The release of both Ni and Co was highest in the acidic and complexing fluids simulating the gastric environment and an inhalation scenario of small powders (artificial lysosomal fluid). Relatively high corrosion resistance and lower levels of released Ni and Co were observed in all fluids for all alloy powders compared with the corresponding pure metals. The extent of released metals was low for powders with a passive surface oxide. This study strongly emphasizes the importance of considering alloying effects in toxicological classification and/or regulation of Ni and Co in alloys and metals.
Topics: Alloys; Cobalt; Humans; Nickel; Occupational Exposure; Powders; Surface Properties
PubMed: 32320011
DOI: 10.1093/annweh/wxaa042 -
Sensors (Basel, Switzerland) Jun 2022This paper mainly focuses on various types of robots driven or actuated by shape memory alloy (SMA) element in the last decade which has created the potential... (Review)
Review
This paper mainly focuses on various types of robots driven or actuated by shape memory alloy (SMA) element in the last decade which has created the potential functionality of SMA in robotics technology, that is classified and discussed. The wide spectrum of increasing use of SMA in the development of robotic systems is due to the increase in the knowledge of handling its functional characteristics such as large actuating force, shape memory effect, and super-elasticity features. These inherent characteristics of SMA can make robotic systems small, flexible, and soft with multi-functions to exhibit different types of moving mechanisms. This article comprehensively investigates three subsections on soft and flexible robots, driving or activating mechanisms, and artificial muscles. Each section provides an insight into literature arranged in chronological order and each piece of literature will be presented with details on its configuration, control, and application.
Topics: Alloys; Mechanical Phenomena; Muscles; Robotics; Shape Memory Alloys
PubMed: 35808360
DOI: 10.3390/s22134860 -
Zhongguo Xiu Fu Chong Jian Wai Ke Za... Mar 2024To review the research progress of magnesium and magnesium alloy implants in the repair and reconstruction of sports injury. (Review)
Review
OBJECTIVE
To review the research progress of magnesium and magnesium alloy implants in the repair and reconstruction of sports injury.
METHODS
Relevant literature of magnesium and magnesium alloys for sports injury repair and reconstruction was extensively reviewed. The characteristics of magnesium and its alloys and their applications in the repair and reconstruction of sports injuries across various anatomical sites were thoroughly discussed and summarized.
RESULTS
Magnesium and magnesium alloys have advantages in mechanical properties, biosafety, and promoting tendon-bone interface healing. Many preclinical studies on magnesium and magnesium alloy implants for repairing and reconstructing sports injuries have yielded promising results. However, successful clinical translation still requires addressing issues related to mechanical strength and degradation behavior, where alloying and surface treatments offer feasible solutions.
CONCLUSION
The clinical translation of magnesium and magnesium alloy implants for repairing and reconstructing sports injuries holds promise. Subsequent efforts should focus on optimizing the mechanical strength and degradation behavior of magnesium and magnesium alloy implants. Conducting larger-scale biocompatibility testing and developing novel magnesium-containing implants represent new directions for future research.
Topics: Humans; Magnesium; Athletic Injuries; Alloys; Prostheses and Implants; Materials Testing; Sports Medicine; Absorbable Implants; Corrosion
PubMed: 38500435
DOI: 10.7507/1002-1892.202401072 -
Dental Materials Journal Jun 2020The aim of this study was to construct a Ti-Nb-Cu ternary phase diagram that plays the role of a map for developing new titanium alloys with excellent machinability and...
The aim of this study was to construct a Ti-Nb-Cu ternary phase diagram that plays the role of a map for developing new titanium alloys with excellent machinability and mechanical properties. Fifteen experimental Ti-Nb-Cu ternary alloys composed of Ti-5-30%Nb-2-20%Cu were designed, and ingots made using Ar-arc melting furnace before casting to generate specimen. The alloy castings were evaluated in terms of their microstructures and alloy phases. A Ti-Nb-TiCu pseudo-ternary phase diagram was constructed using X-ray diffractmetry results. Three alloy phases (α-Ti, β-Ti and TiCu) were established within the specimen. Furthermore, the prescence of two-phase coexistence regions (α+TiCu, α+β and β+TiCu), and three-phase coexistence region (α+β+TiCu) was noted. The findings obtained through microstructural observation corresponded well with the constructed phase diagram.
Topics: Alloys; Dental Alloys; Titanium; X-Ray Diffraction
PubMed: 31969544
DOI: 10.4012/dmj.2018-394 -
ACS Applied Bio Materials Nov 2023The utilization of guided tissue regeneration membranes is a significant approach for enhancing bone tissue growth in areas with bone defects. Biodegradable magnesium...
The utilization of guided tissue regeneration membranes is a significant approach for enhancing bone tissue growth in areas with bone defects. Biodegradable magnesium alloys are increasingly being used as guided tissue regeneration membranes due to their outstanding osteogenic properties. However, the degradation rates of magnesium alloy bone implants documented in the literature tend to be rapid. Moreover, many studies focus only on the initial 3-month period post-implantation, limiting their applicability and impeding clinical adoption. Furthermore, scant attention has been given to the interplay between the degradation of magnesium alloy implants and the adjacent tissues. To address these gaps, this study employs a well-studied magnesium-aluminum (Mg-Al) alloy membrane with a slow degradation rate. This membrane is implanted into rat skull bone defects and monitored over an extended period of up to 48 weeks. Observations are conducted at various intervals (2, 4, 8, 12, 24, and 48 weeks) following the implantation. Assessment of degradation behavior and tissue regeneration response is carried out using histological sections, micro-CT scans, and scanning electron microscopy (SEM). The findings reveal that the magnesium alloy membranes demonstrate remarkable biocompatibility and osteogenic capability over the entire observation duration. Specifically, the Mg-Al alloy membranes sustain their structural integrity for 8 weeks. Notably, their osteogenic ability is further enhanced as a corrosion product layer forms during the later stages of implantation. Additionally, our in vitro experiments employing extracts from the magnesium alloy display a significant osteogenic effect, accompanied by a notable increase in the expression of osteogenic-related genes. Collectively, these results strongly indicate the substantial potential of Mg-Al alloy membranes in the context of guided tissue regeneration.
Topics: Rats; Animals; Alloys; Magnesium; Aluminum; Bone Regeneration; Osteogenesis
PubMed: 37865928
DOI: 10.1021/acsabm.3c00488 -
Biosensors May 2023Doxorubicin (DOX) is widely used in chemotherapy as an anti-tumor drug. However, DOX is highly cardio-, neuro- and cytotoxic. For this reason, the continuous monitoring...
Doxorubicin (DOX) is widely used in chemotherapy as an anti-tumor drug. However, DOX is highly cardio-, neuro- and cytotoxic. For this reason, the continuous monitoring of DOX concentrations in biofluids and tissues is important. Most methods for the determination of DOX concentrations are complex and costly, and are designed to determine pure DOX. The purpose of this work is to demonstrate the capabilities of analytical nanosensors based on the quenching of the fluorescence of alloyed CdZnSeS/ZnS quantum dots (QDs) for operative DOX detection. To maximize the nanosensor quenching efficiency, the spectral features of QDs and DOX were carefully studied, and the complex nature of QD fluorescence quenching in the presence of DOX was shown. Using optimized conditions, turn-off fluorescence nanosensors for direct DOX determination in undiluted human plasma were developed. A DOX concentration of 0.5 µM in plasma was reflected in a decrease in the fluorescence intensity of QDs, stabilized with thioglycolic and 3-mercaptopropionic acids, for 5.8 and 4.4 %, respectively. The calculated Limit of Detection values were 0.08 and 0.03 μg/mL using QDs, stabilized with thioglycolic and 3-mercaptopropionic acids, respectively.
Topics: Humans; Alloys; Doxorubicin; Sulfides; Zinc Compounds
PubMed: 37366961
DOI: 10.3390/bios13060596 -
Analytical Sciences : the International... Sep 2021Silver or palladium shelled gold nanoparticles were fused into alloy nanoparticles by pulsed-laser irradiation. The alloy nanoparticles could carry antibodies on their...
Silver or palladium shelled gold nanoparticles were fused into alloy nanoparticles by pulsed-laser irradiation. The alloy nanoparticles could carry antibodies on their surfaces without affecting their immune functionalities and interact selectively with antigens on a blotting membrane. Silver or palladium ions desorbed from the alloy nanoparticles as reporter ions upon the UV laser irradiation in a mass spectrometer.
Topics: Alloys; Gold; Gold Alloys; Metal Nanoparticles; Palladium; Silver
PubMed: 33678727
DOI: 10.2116/analsci.21N001