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The efficacy of polyether‐ether‐ketone wire as a retainer following orthodontic treatment
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Abstract<sec><title>Objectives

To investigate the efficacy of polyether‐ether‐ketone (PEEK) wire as a fixed orthodontic retainer, by comparing its performance to other retainer wires and optimizing its adhesion to composite bonding materials.

Materials and methods

Retainer wires of 15 mm segments were used, PEEK wires were prepared in cylindrical form with 0.8 mm diameter, and had two surface treatments namely air‐abrasion and conditioning with adhesive system. Three different metallic retainer wires were used for comparison and three tests were performed; two tests measured debonding force and associated wire deflection from acrylic blocks and bovine teeth and one test for pull‐out force. To test debonding force, a vertically directed compressive force was applied to the retainer wires bonded to the acrylic blocks and bovine teeth, while for pull‐out test; a vertically directed tensile force detached the retainer wire.

Results

In both debonding tests, PEEK wires (regardless the surface treatment) had non‐significant difference when compared to each other, or to the other metallic wires, except the dead‐soft coaxial wire group. The dead‐soft coaxial wire group had significant difference when compared to other groups regarding both the force magnitude and maximum deflection, the only exception was the debonding force of the flat braided retainer wires bonded to bovine teeth. In pull‐out test PEEK wires conditioned with adhesive system and the air‐abraded recorded the second and third highest readings respectively.

Conclusions

Within the limitations of this study, the 0.8 mm round PEEK wires have comparable performance—in terms of debonding and pull out forces—to conventional retainers when bonded with 4 mm composite bonding spots; using air‐abrasion for 10 s at 3.5 MPa provided sufficient adhesion of the composite to the wire, and conditioning with adhesive system may provide no further clinical benefit.

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Publication Date
Thu Sep 10 2020
Journal Name
Journal Of Advances In Mathematics
A Study of The Density Property in Module Theory
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In this paper, there are two main objectives. The first objective is to study the relationship between the density property and some modules in detail, for instance; semisimple and divisible modules. The Addition complement has a good relationship with the density property of the modules as this importance is highlighted by any submodule N of M has an addition complement with Rad(M)=0. The second objective is to clarify the relationship between the density property and the essential submodules with some examples. As an example of this relationship, we studied the torsion-free module and its relationship with the essential submodules in module M.

Publication Date
Thu Dec 31 2015
Journal Name
مجلة كلية العلوم الاسلامية
The Secret of Marriage in Christianity A Descriptive Study
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Marriage is a holly secret in Christian religion .So it id natural that its ceremonies acquired religious form .In general the marriage is contracted by minister of religion in presence of the two parties or by a proxy or presence of parents if it is necessary . And to make the condition of publicity for the marriage ,its procedures must be made before witnesses .Also the minister of religionhave to confirm the agreement of the two parties before beginning the procedures.The marriage ceremonies are made.These procedures are religious traditions that includes praying and make blessings and putting the rings in fingers by thepriest . The marriage is a holly secret performed by the crown pray according to the church religious traditions

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Publication Date
Wed Aug 26 2020
Journal Name
International Journal Of Research In Social Sciences And Humanities
THE ROLE OF A PROTEAN CAREER IN HIGH PERFORMANCE
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Publication Date
Fri Aug 30 2019
Journal Name
Journal Of The College Of Education For Women
A Cognitive Linguistic Study of the English Preposition 'in'
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The present study aims at analyzing the polysemy of the English preposition in from the cognitive linguistic (CL) point of view using Evans' and Tyler's approach (2003). The perplexity faced by Iraqi second language learners (L2) due to the multi-usages of this preposition has motivated the researcher to conduct this study. Seventy-six second year university students participated in this experimental study. The data of the pre-test and post-test were analyzed by SPSS statistical editor. The results have shown the following: First, a progress of more than (0.05≤) has been detected as far as students' understanding of the multiple usages of the preposition in is concerned. Second, the results of the questionnaire have s

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Publication Date
Wed Jun 03 2020
Journal Name
Political Sciences Journal
Transitional justice: a study of the concept and mechanisms
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The concept of transitional justice is newly emerging, as it was mainly associated with addressing issues of serious breaches and abuses of human rights during conflicts and situations resulting from violence and the use of force in societies that are in the process of democratization, as transitional justice aims primarily to restore civil peace and rebuild institutions The state needs multidimensional justice: a judicial system that achieves the rule of law, corrective restoration of the wounds of the past, and a distributive characteristic of the redistribution of wealth.

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Publication Date
Tue Nov 01 2022
Journal Name
Journal Of Engineering
The Use of Lightweight Aggregate in Concrete: A Review
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One of the artificial lightweight aggregates with a wide range of applications is Lightweight Expanded Clay Aggregate. Clay is utilized in the production of light aggregates. Using leftover clay from significant infrastructure development projects to manufacture lightweight aggregates has a favorable environmental impact. This research examines the expanded clay aggregate production process and the impact of processing parameters on its physical and mechanical qualities. It also looks at secondary components that can be used to improve the qualities of concrete with expanded clay aggregates. The effect of the quantity of expanded clay aggregate on the fresh, hardened, and durability qualities of concrete is also studied.

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Publication Date
Wed Jun 30 2004
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Factors Affecting the Operation of a Fire Tube Boiler
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Publication Date
Sun Dec 01 2013
Journal Name
Political Sciences Journal
Yemeni political system: a study of the internal variables
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النظام السياسي اليمني : دراسة في المتغيرات الداخلية

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Publication Date
Thu Jun 29 2023
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
A Review of the Electrical Submersible Pump Development Chronology
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The electric submersible pump, also known as ESP, is a highly effective artificial lift method widely used in the oil industry due to its ability to deliver higher production rates compared to other artificial lift methods. In principle, ESP is a multistage centrifugal pump that converts kinetic energy into dynamic hydraulic pressure necessary to lift fluids at a higher rate with lower bottomhole pressure, especially in oil wells under certain bottomhole condition fluid, and reservoir characteristics. However, several factors and challenges can complicate the completion and optimum development of ESP deployed wells, which need to be addressed to optimize its performance by maximizing efficiency and minimizing costs and uncertainties. To

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Publication Date
Thu Jan 01 2015
Journal Name
Political Sciences Journal
Fiscal federalism: a study of the concept and models
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يمثل الأخذ بالنظام الفيدرالي أطاراً تنظيمياً لشكل الدولة و مرحلة تحول مهمة في بنية الدولة العامة في مختلف مجالاتها، فالانتقال من المركزية في أدارة الشؤون العامة للدولة الى النمط الفيدرالي يمثل تحولا بنيوياً وسيكولوجياً ،حيث يكون هنالك توزيع مكاني - عمودي للسلطة والثروة بين الوحدات المكونة للدولة بشكل يختلف كليا عن الحالة المركزية، ونجد صور تنظيمية عديدة تتأسس ضمن اطار الفيدرالية العام ،

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