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.
ABSRTACT Background: Soft liner material is become important in dental prosthetic treatment. They are applied to the surface of the dentures to achieve more equal force distribution , reduce localized pressure and improve denture retention by engaging undercut . So the aim of the study is to evaluate the effect of different surface treatment by air-abrasion AL2O3 and laser treatment with CO2 laser on improving the shear bond strength of the denture liner to acrylic denture base material . Materials and methods: the 30 specimens of heat cured acrylic denture base material (high Impact acrylic )and heat cured soft liner (Vertex ,Nether Lands )were prepared for this study .They were designed and divided according to type of the s
... Show MoreThe research deals with the concept of a New Urbanism as an urban development strategy in the suburbs of cities or in its centers that are affected by pedestrian-oriented design and the possibility of walking, as well as integrating economic classes through the diversity of housing and its costs, and this works to facilitate access to jobs and services while providing more diverse neighborhoods and reducing the use of cars , As designing separate houses in the suburbs and increasing car trips poses a threat to the environment and the quality of urban life, and thus the new urban provides a good strategy for developing
... Show MoreThe subject of fear is one of the most important tasks that one should seek to find out the reasons behind it, and push it up with all its sound mental concepts.
The main reason for the lack of security and fear and disturbance in the world is to commit the legitimate violations that God warned us in his Holy Book as well as in the Sunnah of His Prophet (peace be upon him).
The talk about the causes of fear in the Koran is not limited to the word (fear) Fakk but came in different and varied methods such as (horror) and (awe) and (shares) and (narrow).
Light naphtha one of the products from distillation column in oil refineries used as feedstock for gasoline production. The major constituents of light naphtha are (Normal Paraffin, Isoparaffin, Naphthene, and Aromatic). In this paper, we used zeolite (5A) with uniform pores size (5Aº) to separate normal paraffin from light naphtha, due to suitable pore size for this process and compare the behavior of adsorption with activated carbon which has a wide range of pores size (micropores and mesopores) and high surface area. The process is done in a continuous system - Fixed bed reactor- at the vapor phase with the constant conditions of flow rate 5 ml/min, temperature 180oC, pressure 1.6 bar and 100-gram weight o
... Show MoreFurfural is a toxic aromatic aldehyde that can cause a severe environmental problem especially the wastewater drown from petroleum refinery units. In the present work, a useless by-product from local furniture manufacturing industry; sawdust was used as raw material for the preparation of activated carbon which is chemically activated with phosphoric acid. The effect of adsorption variables which include initial pH of solution (2-9), agitation speed (50-250) rpm, agitation time (15-120) min, initial concentration of furfural (50-250) ppm, and amount of adsorbent material (0.5-2.5) g for the three adsorbents used (prepared activated carbon, commercial activated carbon and raw sawdust) were investigated in a batch process
... Show MoreBackground: Errors of horizontal condylar inclinations and Bennett angles had largely affected the articulation of teeth and the pathways of cusps. The aim of this study was to estimate and compare between the horizontal condylar (protrusive) angles and Bennett angles of full mouth rehabilitation patients using two different articulator systems. Materials and Methods: Protrusive angles and Bennett angles of 50 adult males and females Iraqi TMD-free full mouth rehabilitation patients were estimated by using two different articulator systems. Arbitrary hinge axis location followed by protrusive angles and Bennett angles, estimation was done by a semiadjustable articulator system. A fully adjustable articulator system was utilized to locate th
... Show MoreWet granulation method was used instead of conventional pan coating or fluidized –bed coating technique to prepare enteric-coated diclofenac sodium granules, using ethanolic solution of EudragitTM L100 as coating, binding and granulating agent .Addition of PEG400 or di-n-butyl phthalate as a plasticizer was found to improve the enteric property of the coat.
Part of the resulted granules was filled in hard gelatin capsules (size 0), while the other part was compressed into tablets with and without disintegrant.
The release profile of these two dosage forms in 0.1N HCl (pH 1.2)for 2 hours, and in phosphate buffer (pH 6.8) for 45 minutes as well as the release kinetic were compared with that of the en
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