scholarly journals A Critical Appraisal of the Use and Properties of Nickel–Titanium Dental Alloys

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7859
Author(s):  
Petra Močnik ◽  
Tadeja Kosec
Keyword(s):  
Metal Ions ◽  
Human Body ◽  
Niti Alloy ◽  
Nickel Titanium ◽  
Stable Steady State ◽  
Corrosion Properties ◽  
Nickel Ions ◽  
Corrosion Resistant Alloy ◽  
Subsequent Effect ◽  
Niti Wires

Nickel–titanium (NiTi) archwires are used in dentistry for orthodontic treatment. NiTi alloys have favourable mechanical characteristics, such as superelasticity and shape memory, and are also known as a corrosion-resistant alloy. In specific cases, an archwire could be attacked by certain types of corrosion or wear degradation, which can cause the leaching of metal ions and a hypersensitive response due to increased concentrations of Ni in the human body. A systematic search of the literature retrieved 102 relevant studies. The review paper focuses on three main fields: (i) electrochemical properties of NiTi wires and the effect of different environments on the properties of NiTi wires (fluoride and low pH); (ii) tribocorrosion, a combination of chemical and mechanical wear of the material, and (iii) the biocompatibility of NiTi alloy and its subsequent effect on the human body. The review showed that corrosion properties are affected by microstructure, pH of saliva and the presence of fluorides. A high variation in published results should be, therefore, interpreted with care. The release of nickel ions was assessed using the same unit, showing that the vast majority of metal ions were released in the first few days of exposure, then a stable, steady state was reached. In tribocorrosion studies, the increased concentrations of Ni ions were reported.

scholarly journals Influence of intraoral application of antiseptics and fluorides during orthodontic treatment on corrosion and mechanical characteristics of nickel-titanium alloy in orthodontic appliances

2021 ◽  
Author(s):  
Tihana Zibar Belasic ◽  
Biljana Pejova ◽  
Helena Otmacic Curkovic ◽  
Ervin Kamenar ◽  
Bojana Cetenovic ◽  
...  
Keyword(s):  
Niti Alloy ◽  
Surface Characteristics ◽  
Nickel Titanium ◽  
Localized Corrosion ◽  
Oral Exposure ◽  
Orthodontic Appliances ◽  
General Corrosion ◽  
Corrosion Properties ◽  
Dental Biofilm

ABSTRACT Objectives To explore whether the commercial agents recommended for controlling dental biofilm formation had a significant effect in vivo on mechanical and corrosion properties of nickel-titanium (NiTi) alloy. Materials and Methods NiTi archwires (dimensions 0.508 × 0.508 mm) were collected from 36 orthodontic patients aged 13–42 years after a 3-month intraoral exposure. Three experimental groups were formed: (1) subjects conducting regular oral hygiene, (2) subjects who used fluorides for intensive prophylaxis for the first month, and (3) subjects who used chlorhexidine in the same manner. Corrosion behavior, surface characteristics, stiffness, hardness, and friction were analyzed. Results Exposure to intraoral conditions significantly reduced the stiffness and hardness of the NiTi alloy (P ≤ .015). Fluoride tended to reduce stiffness and hardness more than did saliva or antiseptic, but not significantly. Roughness and friction were not significantly influenced by oral exposure. Intraoral aging predominantly produced general corrosion independent of the adjuvant prophylactic agent, although localized corrosion may also have occurred. Conclusions Fluorides and the antiseptic chlorhexidine do not increase corrosion more than saliva itself, nor do they further modify the mechanical properties of the NiTi alloy.

scholarly journals Nickel-Catcher-Doped Zwitterionic Hydrogel Coating on Nickel–Titanium Alloy Toward Capture and Detection of Nickel Ions

2021 ◽  
Vol 9 ◽  
Author(s):  
Xiaoyi Fu ◽  
Xi Liu ◽  
Dezhao Hao ◽  
Wuyi Xiao ◽  
Qiong Nie ◽  
...  
Keyword(s):  
Medical Devices ◽  
Niti Alloy ◽  
Nickel Titanium ◽  
Cytotoxic Activities ◽  
Ion Leakage ◽  
Nickel Ion ◽  
Nickel Ions ◽  
Potential Possibility ◽  
Bacteria Adhesion ◽  
Chelation Reaction

Nickel–titanium (NiTi) alloys show broad applicability in biomedical fields. However, the unexpected aggregation of bacteria and the corrosion of body fluid on NiTi-based medical devices often lead to the leakage of nickel ions, resulting in inevitable allergic and cytotoxic activities. Therefore, the capture and detection of nickel ions are important to avoid serious adverse reactions caused by NiTi-based medical devices. Herein, we presented a nickel ion capture strategy by the combination of zwitterionic hydrogels as anti-bacteria layers and carbon disulfide (CS2) components as nickel-catchers (Ni-catchers). On the one hand, the hydration layer of zwitterionic hydrogel can efficiently inhibit bacteria adhesion and reduce nickel ions leakage from NiTi corrosion. On the other hand, Ni-catchers can capture leaked nickel ions from NiTi alloy actively by chelation reaction. Therefore, this strategy shows great capabilities in resisting bacteria adhesion and capturing nickel ions, providing the potential possibility for the detection of nickel ion leakage for implantable biomedical materials and devices.

scholarly journals Load-Deflection Characteristics of Superelastic Nickel-Titanium Wires

2007 ◽  
Vol 77 (6) ◽  
pp. 991-998 ◽  
Author(s):  
Theodosia N. Bartzela ◽  
Christiane Senn ◽  
Andrea Wichelhaus
Keyword(s):  
Niti Alloy ◽  
Permanent Deformation ◽  
Nickel Titanium ◽  
Bending Test ◽  
Qualitative Behavior ◽  
Treatment Needs ◽  
Orthodontic Wires ◽  
Three Point Bending ◽  
Niti Wires ◽  
The Given

Abstract Objective: To determine the mechanical properties of commercially available thermodynamic wires and to classify these wires mathematically into different groups. Materials and Methods: The samples examined were 48 nickel-titanium (NiTi) alloy orthodontic wires commercially available from five manufacturers. These samples included 0.016-inch, 0.016- × 0.022-inch, 0.017- × 0.025-inch, and 0.018- × 0.025-inch wires. The superelastic properties of the NiTi wires were evaluated by conducting the three-point bending test under uniform testing conditions. The group classification was made under mathematically restricted parameters, and the final classification was according to their clinical plateau length. Results: The orthodontic wires tested are classified as follows: (1) true superelastic wires, which presented a clinical plateau length of ≥0.5 mm; (2) borderline superelastic with a clinical plateau length of <0.5 mm and >0.05 mm; and (3) nonsuperelastic, with a clinical plateau length of ≤0.05 mm. The results showed that the range of products displays big variations in quantitative and qualitative behavior. A fraction of the tested wires showed weak superelasticity, and others showed no superelasticity. Some of the products showed permanent deformation after the three-point bending test. Conclusion: A significant fraction of the tested wires showed no or only weak superelasticity. The practitioner should be informed for the load-deflection characteristics of the NiTi orthodontic wires to choose the proper products for the given treatment needs.

The Binding and Viscometric Studies of Ni+2, Co+2 and Mn+2 Ions with Protein by Spectrometric and pH Metric Techniques

2019 ◽  
Vol 9 (2) ◽  
pp. 151-162
Author(s):  
Shveta Acharya ◽  
Arun Kumar Sharma
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Protein Molecule ◽  
Vital Role ◽  
Sufficient Evidence ◽  
Structural Requirement ◽  
Nickel Ions ◽  
Cobalt Ions ◽  
Lower Temperature ◽  
Specific Oxidation

Background: The metal ions play a vital role in a large number of widely differing biological processes. Some of these processes are quite specific in their metal ion requirements. In that only certain metal ions, in specific oxidation states, can full fill the necessary catalytic or structural requirement, while other processes are much less specific. Objective: In this paper we report the binding of Mn (II), Ni (II) and Co (II) with albumin are reported employing spectrophotometric and pH metric method. In order to distinguish between ionic and colloidal linking, the binding of metal by using pH metric and viscometric methods and the result are discussed in terms of electrovalent and coordinate bonding. Methods: The binding of Ni+2, Co+2 and Mn+2 ions have been studied with egg protein at different pH values and temperatures by the spectrometric technique. Results: The binding data were found to be pH and temperature dependent. The intrinsic association constants (k) and the number of binding sites (n) were calculated from Scatchard plots and found to be at the maximum at lower pH and at lower temperatures. Therefore, a lower temperature and lower pH offered more sites in the protein molecule for interaction with these metal ions. Statistical effects seem to be more significant at lower Ni+2, Co+2 and Mn+2 ions concentrations, while at higher concentrations electrostatic effects and heterogeneity of sites are more significant. Conclusion: The pH metric as well as viscometric data provided sufficient evidence about the linking of cobalt, nickel and manganese ions with the nitrogen groups of albumin. From the nature and height of curves in the three cases it may be concluded that nickel ions bound strongly while the cobalt ions bound weakly.

scholarly journals Removal of Chromium and Nickel from Electroplating Wastewater Using Magnetite Particulate Adsorbent: (1) Effect of pH, Contact Time and Dosage, (2) Adsorption Isotherms and Kinetics

2016 ◽  
Vol 10 (7) ◽  
pp. 222 ◽  
Author(s):  
Donatus Dube ◽  
Champaklal T. Parekh ◽  
Bothwell Nyoni
Keyword(s):  
Metal Ions ◽  
City Council ◽  
Optimum Process ◽  
Order Kinetic ◽  
Heavy Load ◽  
Nickel Ions ◽  
Wide Range ◽  
Adsorption Processes ◽  
Wastewater Samples ◽  
Electroplating Process

Wastewater discharged into municipal sewer systems from electroplating process plants contains a heavy load of metal ions and often requires pre-discharge treatment. Treatment of wastewater to reduce the concentration of metal ions employing an adsorption process has been studied using a wide range of adsorbents. In this work, the concentrations of chromium and nickel ions in wastewater samples from a local electroplating shop were found to be above the limits set out by the Bulawayo City Council, and the Environmental Management Agency, a statutory agency under the Ministry of Environment and Tourism, Government of Zimbabwe. Furthermore, the removal of chromium and nickel ions from the wastewater using magnetite as an adsorbent is studied. Magnetite particulate adsorbent used in this experiment has demonstrated to be an effective adsorbent material. At the optimum process operating pH of 4 – 7 the absorbent was able to achieve removal rates of up to 99% for chromium and 98% for nickel. The adsorption processes for chromium and nickel have been proven to be physical in nature using the Dubinin-Radushkevich isotherm model. Also, the adsorption kinetics data fit well with pseudo second-order kinetic model.

scholarly journals The Influence of Heavy Metal Ions on the Viability and Metabolic Enzyme Activity of the Marbled Crayfish Procambarus virginalis (Lyko, 2017)

2018 ◽  
Vol 70 ◽  
pp. 11-23 ◽  
Author(s):  
Oleg Marenkov ◽  
Mykola V. Prychepa ◽  
Julia Kovalchuk
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Enzyme Activity ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Physiological State ◽  
Metabolic Enzyme ◽  
Nickel Ions ◽  
The Individual ◽  
Marbled Crayfish

In the experiment with marbled crayfishProcambarusvirginalis(Lyko, 2017), chronic effects of various concentrations of heavy metal ions on the physiological state and enzyme activity were investigated. The obtained results showed that among the investigated heavy metals nickel ions influenced the weight indexes and mortality of crustaceans the most negatively. According to the results of the research, significant changes were noted in the individual biochemical parameters of marbled crayfish under the influence of manganese, lead and nickel ions. The most significant changes in the activity of lactate dehydrogenase were detected in muscle tissues affected by manganese and nickel ions. A significant decrease in the activity of succinate dehydrogenase in muscle of marbled crayfish was determined after the action of heavy metal ions. Investigation of changes in the activity of alkaline phosphatase under the influence of the ions of manganese, lead and nickel has its own characteristics, which indicates certain violations in the tissues of cell membranes. Changes in the activity of enzymes were also reflected in the overall protein content. Changes in these parameters may indicate a rapid biochemical response of crustaceans to the toxic effects of heavy metals.

scholarly journals The structural chemistry of zinc(ii) and nickel(ii) dithiocarbamate complexes

2021 ◽  
Vol 19 (1) ◽  
pp. 974-986
Author(s):  
Tanzimjahan A. Saiyed ◽  
Jerry O. Adeyemi ◽  
Damian C. Onwudiwe
Keyword(s):  
Complex Formation ◽  
Metal Ions ◽  
Structural Properties ◽  
Binding Sites ◽  
Biological Systems ◽  
Structural Chemistry ◽  
Metal Coordination ◽  
Nickel Ions ◽  
Coordination Modes ◽  
Biomedical Fields

Abstract Dithiocarbamate complexes are of immense interest due to their diverse structural properties and extensive application in various areas. They possess two sulfur atoms that often act as the binding sites for metal coordination in a monodentate, bidentate, or anisodentate fashion. These different coordination modes enhance the possibility for complex formation and make them useful in different areas especially in biomedical fields. A synergy exists in the metal ions and dithiocarbamate moieties, which tends to exert better properties than the respective individual components of the complex. These improved properties have also been attributed to the presence of the C–S bonds. Zinc and nickel ions have been majorly found to bind to the dithiocarbamate in bidentate modes, and consequently different geometries have resulted from this interaction. The aim of this review is to present some studies on the synthesis, structural chemistry, and the relevance of zinc and nickel dithiocarbamates complexes especially in biological systems.

scholarly journals An evaluation of two types of nickel-titanium wires in terms of micromorphology and nickel ions’ release following oral environment exposure

2015 ◽  
Vol 16 (1) ◽  
Author(s):  
Abdul Razzak A Ghazal ◽  
Mohammad Y Hajeer ◽  
Rabab Al-Sabbagh ◽  
Ibrahim Alghoraibi ◽  
Ahmad Aldiry
Keyword(s):  
Nickel Titanium ◽  
Nickel Ions ◽  
Environment Exposure ◽  
Oral Environment

Colloidal particle based electrodeposition coatings on NiTi alloy: Reduced releasing of nickel ions and improved biocompatibility

2018 ◽  
Vol 230 ◽  
pp. 228-231 ◽  
Author(s):  
Long Meng ◽  
Yang Li ◽  
Kai Pan ◽  
Ye Zhu ◽  
Wei Wei ◽  
...  
Keyword(s):  
Colloidal Particle ◽  
Niti Alloy ◽  
Nickel Ions

Evaluation of Prestressing with a Shape Memory Alloy

1997 ◽  
Vol 503 ◽  
Author(s):  
Arup K. Maji
Keyword(s):  
Shape Memory ◽  
Prestressed Concrete ◽  
Strain Energy ◽  
Event Rate ◽  
Martensite Phase ◽  
Nickel Titanium ◽  
Prestress Losses ◽  
Higher Temperature ◽  
Prestressed Concrete Bridge ◽  
Niti Wires

ABSTRACTThe paper addresses the possibility of using shape-memory effect in Nitinol (Nickel-Titanium) alloy to remedy prestress losses in aging concrete beams. Straight annealed NiTi in the low temperature martensite phase can undergo large plastic deformations. This deformation and strain energy is recoverable when the material transforms to the higher temperature (about 55° C) austentite phase. This phenomena can be exploited to induce curvature, hence prestressing, by embedding NiTi wires and ropes in a structural member. Depending on the type of wire used its actuation effect can be reversed as necessary, creating the possibility of a smart prestressed concrete bridge of the future.Materials aspect studied in this project include the bond between NiTi wires and the host composite material, through mechanical testing and microscopy. An evaluation of the phase transformation is conducted using Acoustic Emission (AE) technology. AE event rate, locations and characteristics were evaluated during the actuation process.

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