Background: Reduction in bond strength when bonding was done immediately after intracoronal bleaching procedure has been recognized. The purpose of this study is to assess the effect of antioxidants (10% sodium ascorbate (SA), 0.1M thiourea and7% sodium bicarbonate (SB)) on reversing bonding strength of composite resin to bleached dentin. Materials and method: Sixty upper 1st premolar teeth, were selected, the crowns of the teeth were embedded in acrylic resin blocks exposing a flat dentin from the buccal surface, then divided into 6 groups (10 samples each). Bleaching for the experimental groups was performed using 35% hydrogen peroxide bleaching gel (pola–office).Group A (Negative control group; dentin samples immediately bonded with composite without bleaching)Group B (Positive control group; dentin samples bleached and immediately bonded with composite). Group C (Dentin samples bleached and stored for 14 days in DDW then bonded with composite). Group D (Dentin samples bleached and treated with 10% (SA) then immediately bonded with composite). Group E (Dentin samples bleached and treated with 0.1M thiourea then immediately bonded with composite). Group F (Dentin samples bleached and treated with 7% SB then immediately bonded with composite).The shear bond strength was determine using instron testing machine. Results: Bleaching the dentin with 35 % hydrogen peroxide gel for 24 minutes resulted in reduction in bond strength of the bleached teeth when bonding was performed immediately after bleaching. Delayed bonding of composite to the bleached dentin for 14 days will result in a highly significant increase in the shear bond strength. Conclusion: Treating the bleached dentin with 10% (SA) in water base showed a highly significant increase in the shear bond strength of the composite to dentin and reversing the bond strength value to the level of the unbleached dentin. Treating the bleached dentin with 0.1M thiourea significantly increased the shear bond strength of the composite to dentin.
War was and remains one of the main instruments for the practice of international relations, and has always been a major focus of the study of international relations. War, such as diplomacy, propaganda, etc., is an instrument of national politics. States have used wars to achieve their goals and aspirations and achieve their national interests. War and peace issues are essential to understanding international relations. They are questions that involve the problem of survival.
Today the term "war" is used in many different ways. We talk about Cold War, Hot War, Limited War, Total War, Conventional War, Unconventional War, Civil War, Gang War, Preventive War etc. However, the war continued to exist, and took various forms.
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This study aims to discuss how English Language Textbook (ELT), used in Iraqi schools, can be developed. All Iraqi teachers in Iraq spend much time using ELT textbooks in classrooms, and most of the Iraqi students depend on these textbooks to learn and improve the English language, so choosing an appropriate ELT textbook is so essential. A suitable book must include critical components that fit teachers' and students' needs. The quality of ELT textbooks has been improved dramatically in recent years, even though these textbooks still do not meet students' needs, especially in language communication skills. This study seeks to investigate the most critical components that may make the ELT textbooks are more influential and interactive for Ir
... Show MoreMandali Dam is one of the small dams in Iraq; it is located on Haran Wadi, Gangir, just 3km north-east Mandali City. Mandali dam consists of four main parts, the dam body, the intake structure, the spillway, and the bottom outlet. The dam body is zoned earth filled with a central core. The main purposes of the dam are to maintain flow of Wadi Haran, supplying irrigation and drinking water to Mandali City, and recharging the groundwater. Over a period of seven years of operation, the dam lost its ability to store water due to accumulated sediments within its reservoir. The accumulated sediment is about 2.25million m3. The average annual rate of reduction during this period is about 0.321
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This conducted research, (The Scientific Efforts of Ahmed Mustafa Al-Maraghi) deals with Al-Maraghi's life, birth, upbringing, characteristics, title, family and religion secter, as well as his general biography. And his relationship with scholars, his learning and teaching, and the introduction of the Muhammed Abdo School and the College of Dar Al Uloom, and finally the discussion of his scientific, social and political poin of view, as an interpreter of twentieths century, was appointed as the president of Al-Azhar and Ifta during the days of the royal era, and he studied at the College of Dar Al-Uloom
The aim of the research is to identify the attitudes of Iraqi youth
towards volunteering work by using the survey method and the scale
tool to identify what young volunteers can carry from the attitudes
towards volunteering work because the phenomenon of volunteer
work is of great importance in society. The scale was applied to
(525) volunteers among Iraqi youth. The research reached a set
of results, the most prominent of which is the existence of positive
trends among young people towards volunteering work, meaning
that Iraqi youth volunteers have awareness of the concept of
volunteering correctly. As for their goals of volunteering, they are
humanitarian and social goals for the advancement of society, an
In this paper, the static analysis for finding the best location of boxes inside the composite wing-box structure has been performed. A software ANSYS (ver.11) was used to analyses the Aluminum wing to find the maximum stresses reached in. These results are used as a base for the composite wingbox to find the numbers of layers and location of the box beam and its dimensions so that the composite wingbox may carry the same loading conditions in the Aluminum wing. Analysis showed that a composite wingbox having two boxes is better than the single or triple boxes wing based on stress to weight ratio. Mass saving of (40%) had been achieved when composite wing-box is used instead of Aluminum wing.
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However, the effects of these ideas are still evident
Think of those who follow the footsteps of Muslim scholars and thinkers.
Intellectual source of Gnostic Gnar
And in dealing with issues of Islamic thought
Annalisa intersecting trends of thought, Minya who melts in Masarya and supported him and believes in Bo and extremist Vue,
Lea, trying to throw it with a few times, looks at Elya look
There are those who stand in the opposite position
There are those who stand in a selective compromise, but this school of thought remains
G - the features of Islamic thought that believes in the mind and Imoto in the defense of
An intellectual station and generalized bar
Creed. In his study, the researcher wi