Background: The demand for esthetic orthodontic appliances is increasing; so the esthetic orthodontic archwires were introduced. Among them, Teflon and Epoxy coated stainless steel archwires. The amount of force available from the archwire depends on the structural properties and susceptibility to corrosion. All metallic alloys are changed during immersion in artificial saliva, chlorhexidine mouthwash andtoothpaste, but their behaviors differ from one type to another. They corrode at different rates, which lead to decrease the amount of force applied to the teeth. This in vitro study was designed to evaluate the corrosion pits in stainless steel archwires coated with Teflon and with Epoxy in dry and after immersion in artificial saliva, chlorhexidine(0.2%( (Parodontax) and toothpaste media (Sensodyne) for (1, 7 and 28) days intervals. Moreover, this study is intended to compare the corrosion pits for each type of archwires at these different media among all intervals. Materials and Methods: In this study, two hundred forty pieces of orthodontic wires of Teflon (Hubit) coated Stainless steel (120 pieces) and epoxy (Orthotechnology) coated Stainless steel (120 pieces), rectangular in cross section, size (0.019 x 0.025) inch and 15mm in length divided into four groups according to immersion media: (dry environment group, artificial saliva group, chlorhexidine group and toothpaste group). The atomic force microscope was used to measure the corrosion pits for all samples at dry and wet conditions and after different immersion periods. Results: Statistical analysis showed that there was a highly significant increase in the corrosion pits of Teflon coated stainless steel archwires (P ≤ 0.05) in wet environment at 28 days immersion period.The highest corrosion pits were found in the toothpaste medium for the two archwire types at 28 days immersion period. Conclusion: We can conclude that Epoxy coatedstainless steel archwires are indicated to be used above Teflon coated stainless steel archwires in terms of corrosion resistance. IfTeflon coated stainless steel archwires should to be used, they should be change in shorter periods than Epoxy coated stainless steel archwires type Key words: Esthetic coated archwire, corrosion, Teflon, Epoxy, wet environment, AFM.
Incorporating waste byproducts into concrete is an innovative and promising way to minimize the environmental impact of waste material while maintaining and/or improving concrete’s mechanical characteristics and strength. The proper application of sawdust as a pozzolan in the building industry remains a significant challenge. Consequently, this study conducted an experimental evaluation of sawdust as a fill material. In particular, sawdust as a fine aggregate in concrete offers a realistic structural and economical possibility for the construction of lightweight structural systems. Failure under four-point loads was investigated for six concrete-filled steel tube (CFST) specimens. The results indicated that recycled lightweight co
... Show MoreQuercetin, one of the flavonoids family member, can be found in many vegetables, fruits, and beverages with a noticeable nutritional pharmacological properties. This study was aimed to evaluate the ability of quercetin to inhibit lipopolysaccharide (LPS) that induced lethal toxicity in vivo, and to elucidate the importance of the quercetin as an antitumor agent in breast cancer cell line MCF-7.In vivo experiments included the effect of hesperidin and LPS on the liver and spleen of male mice. In the liver, the antioxidant activity was measured by estimating the concentration of glutathione (GSH), and catalase (CAT), while in the spleen, the concentration of cytokines was measured including IL-33 and TNF-α. In vitro experiments included MTT
... Show MoreHydrochloric acid (HCl) is a substance that is frequently utilized in industrial operations for important tasks such as chemical cleaning and pickling metallic surfaces.Therefore, the corrosion inhibition ability of three newly synthesized quinazoline derivatives namely, 3-allyl-2-(propylthio) quinazolin-4(3H)-one) (APQ), (3-allyl-2-(allylthio) quinazolin-4(3H)-one) (AAQ), (3-allyl- 2-( Prop -2-yn -1-ylthio) Quinazolin - 4 (3H) - one) (AYQ) were theoretically determined and these compounds were characterized using Fourier Transform Infra-Red (FTIR) and 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopic. A series of quantum chemical properties of these derivatives: EHOMO, ELUMO, energy gap (ΔE),dipole moment (μ), hardness (η), soft
... Show MoreThe purpose of this study is designate quenching and tempering heat treatment by using Taguchi technique to determine optimal factors of heat treatment (austenitizing temperature, percentage of nanoparticles, type of base media, nanoparticles type and soaking time) for increasing hardness, wear rate and impact energy properties of 420 martensitic stainless steel. An (L18) orthogonal array was chosen for the design of experiment. The optimum process parameters were determined by using signal-to-noise ratio (larger is better) criterion for hardness and impact energy while (Smaller is better) criterion was for the wear rate. The importance levels of process parameters that effect on hardness, wear rate and impact energy propertie
... Show MoreSports risk has become a threat to the sports sector in general and the impact on an efficient player and the old stadiums in particular. So have such a thing fertile ground of global insurance companies to exploit it optimally exploited through the development and marketing of insurance lids for the provision of protection for athletes of different risks they may face, which contributed to the growth and development of the performance of these companies and helped in the emergence of sports insurance specialist firms. And through the insurance process in the field of sports and where the insurance is a type of social solidarity. The main problem is this spirit manifested search in question is whether to embrace sports institutions sport
... Show MoreCorrosion inhibitors are widely used in industry to reduce the corrosion rate of metals and alloys. Corrosion inhibitors adsorb onto metallic surfaces and insulate them from deterioration. Plants abundant in nature offer a cost-effective replacement for toxic chemical inhibitors on the market. The current research used the potentiostatic polarization technique at room temperature to explore the inhibitory impact of water hyacinth extract on the corrosion of low-carbon steel specimens in a 3.5% NaCl solution. The Tafel curve was used to assess corrosion inhibition activity, with the best inhibition efficiency reaching 79.36% at a concentration of 200 ppm. Cyclic polarization indicated the type of corrosion was general corrosion. The
... Show MoreNanostructured Al2O3has been applied as a protective coating against corrosion of the carbon steel (C.S) in seawater environment (3.5% NaCl) at temperatures range (298-328)K. Aluminananoparticles were deposited on carbon steel substrates by cathodic electrophoretic deposition (EPD) with ethanol as suspension medium and poly(acrylic acid) (PAA) as polymeric charging agent. Meanwhile, thesurface morphology was examined using Atomic-force microscopy (AFM). The cross-section AFM showed that the particles sizes for the Al2O3 NPs is around 60-80 nm. The anticorrosion behaviour of coated C.S was investigated in 3.5% NaCl at temperature range 298-328 K by potentiodynamic polarization measurements. Results show that using PAA in suspension coat incr
... Show More: Clobetasol propionate (CP) is a potent corticosteroid used for skin conditions but often causes side effects due its systemic absorption. To improve its solubility and reduce it side effects (like skin irritation, skin atrophy, hypopigmentation and steroidal acne), Microsponge (Msg) has been employed as a unique three-dimensional particle that can encapsulate hydrophilic and lipophilic drugs. This study aims to develop and evaluate CP Msg-loaded hydrogels. Two Clobetasol-loaded ethylcellulose-based Msg formulas were prepared using the quasi-emulsion solvent diffusion method, then they were incorporated into Carbopol hydrogel. Two ratios of Carbopol 940 (1% and 1.5% w/w) were used. The prepared hydrogel were assessed for appearance, pH, dr
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