ABSTRACT Background:Hydrogen absorption and related degradation in the mechanical properties of Ni-Ti based orthodontic wires has been demonstrated following exposure to fluoride prophylactic agents. This study was designed to investigate the effects of three fluoride containing agents on the load deflection characteristics of heat activated nickel titanium arch wires during unloading phase. Material and method: Eighty specimens of heat activated nickel titanium arch wires were obtained from Ortho Technology Company, half of which had a 0.016 inch round and 0.019x0.025 rectangular. Ten specimens from both wire size were immersed in one of the tested fluoride prophylactic agents (neutral sodium fluoride gel, stannous fluoride gel or phos-flur mouth rinse) or in the controlled medium “normal salineâ€, and incubated at 37ËšC for sixty minutes. A Wp 300 universal material testing machine was modified and used to perform a three point bending test in a water path at 37ËšC ±1ËšC.The statistical difference between the different agents were analyzed using ANOVA and LSD tests. Results: The unloading forces at 0.5, 1.0, and 1.5 mm where significantly reduced especially in neutral sodium fluoride treated specimens. Conclusion: Based on the results founded in th study it might be preferred to use prophylactic agent with the least fluoride ions concentration.It can be concluded that the tested agents have only a limited effect on the load deflection behavior of the heat activated Ni-Ti wires, in a way that they do not have a clinically significant effect on the mechanical behavior of these wires.
Wheat is rich in sources of fiber, oligosaccharides, and resistant starch, simple carbohydrates which may have a protective role against carcinoma. Additionally, Whole wheat/bran as well includes contains phytochemicals such as flavonoids, lignans, folate, phytosterols, phenolic acids, and tocols. The above phytochemicals suitable forms antioxidant and cholesterol-reducing activities. Phytoestrogens are regarded as especially essential in the preventative measures of hormonally dependent malignancies such as breast cancer (BC). In this study lowered BC risk has been associated with whole grain/bran consumption with an odds ratio (OR=0.24 and 95 %CI=0.10-0.56). Wheat/bran appears to have a reliable protective impact against BC. While intake
... Show MoreThe electoral mechanism is remarkably clear, a political tool for institutional construction, directing political life, forming the political scene, and forming the partisan scene. This process was through the design of electoral laws, as elections in Tunisian political history represented the indicator of its slow and accelerated transformations, so The elections in Tunisia usually coincide with important political stages, accompanied by legislative or constitutional amendments in general, Islamic or secular forces have played a fundamental role in promoting the democratic experience and the principle of the peaceful transfer of power. This led to the formation of a national consensus that would help the country not enter into political
... Show MoreBraces in straight bridge systems improve the lateral-torsional buckling resistance of the girders by reducing the unbraced length, while in horizontally curved and skew bridges, the braces are primary structural elements for controlling deformations by engaging adjacent girders to act as a system to resist the potentially large forces and torques caused by the curved or skewed geometry of the bridge. The cross-frames are usually designed as torsional braces, which increase the overall strength and stiffness of the individual girders by creating a girder system that translates and rotates as a unit along the bracing lines. However, when they transmit the truck’s live load forces, they can produce fatigue cracks at their connection
... Show MoreAfter its 35-year occupation of Japan and the US occupation, Korea has set its sights on a long-term goal of building its country and establishing its foundations, unobtrusive and unchecked by the problems and wars that have stood in the way of its goal, surpassing all odds and achieving the best results. The most powerful Asian and global economies, which gained the respect of the world and its appreciation of the experience has become referred to as boys
The current investigation conducted to examine the anatomical aspects of the Arum colocasia L. cultured in Iraq. The study included the anatomical characteristics of the different plant parts, including the root, stem and leaf, the results of the study on the vegetative parts were shown the important anatomical characteristics in terms of the form of the sections reviewed and vertical in them, and the study of their tissues, as well as the stomata complexities and the thickness of the epidermis, vascular bundles, pith, additionally the dimensions of mesophyll and in blade of the leaf. The research was conducted as it is one of the monocotyledon plants and because of the lack of anatomical studies on it, therefore it was studied to know the
... Show MoreThe present work included a study of benthic algae on two substrates: rocks and clay on a section of the Tigris River at the Al-Atifiyah site in the fall of 2018. The result of this study was recorded 89 species belong to 50 genus of benthic algae on both substrates and composed of Bacillariophyceae (59.6%, 61.2%), Chlorophyceae (25.8%, 20.4%) and Cyanophyceae (14.5%, 18.3%) respectively on epilithic and epipelic algae. The present study was recorded the highest total algae cell density (1173.2 cells *103/cm2) on epilithic algae while the lowest total algae cell density was recorded on epipelic algae (76.95 cells *103/gm). For measure div
The current investigation conducted to examine the anatomical aspects of the Arum colocasia L. cultured in Iraq. The study included the anatomical characteristics of the different plant parts, including the root, stem and leaf, the results of the study on the vegetative parts were shown the important anatomical characteristics in terms of the form of the sections reviewed and vertical in them, and the study of their tissues, as well as the stomata complexities and the thickness of the epidermis, vascular bundles, pith, additionally the dimensions of mesophyll and in blade of the leaf. The research was conducted as it is one of the monocotyledon plants and because of the lack of anatomical studies on it, therefore it was studied to know the
... Show MoreBackground: Developing Goalkeeper’s performance is imperative to defence the goal. As the Football match’s nature needs implementning the skill with strength, and speed. so, the Goalkeeper demands special physical abilities that enabling him the ball blocking skill masterly. Objetive: The study aimed to identify the effect of developing some special physical abilities on the goalkeeper’s performance level while blocking executed balls from the penalty mark in football using plyometric training. Methodology: The experimental approach (continuous training that divided into two phases: General preparation, and Special preparation stage) was adopted for one experimental group by pre/post-measurements. The research sample was delib
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