Background: Thermocycling simulates the temperature dynamics in the oral environment. This in vitro study done to measure and compare the effect of thermocycling on the shear bond strength of stainless steel and sapphire brackets bonded to human enamel teeth using light cured orthodontic adhesive and debonded at various time, and to measure adhesive remnant index after debonding. Materials and Methods: one-hundred-twenty extracted upper first premolars for orthodontic reason were used in this study; depending on weather thermocycled or not, the sample was divided into two main groups, then within each group 30 teeth were used for stainless-steel brackets (Bionic®) and for sapphire brackets (Pure®). Both groups were subdivided into three groups (n = 10) according to the debond times: I: debond after 24 hour, II: debond after 7 days and III: debond after 30 days. Within 24 hr, half of the sample was thermocycled manually for 500 complete cycles between 5/55°C and the remaining sample was stored in distilled water at room temperature and water was changed daily until debond time for each group was performed. The adhesive remnant index was tested under 20X magnification lens using stereomicroscope. Results and Conclusions: Both bracket types demonstrated high shear bond strength values before thermocycling (P?0.05), whereas after 500 thermocycles, there were significant changes in shear bond strength resulted in marked reduction in the stainless steel brackets than in the sapphire brackets (P?0.05). Shear bond strength values increased with time for both stainless steel and sapphire brackets with and without thermocycling (P?0.05). The tendency of bond failure was increased at the bracket/adhesive interface rather than enamel/bracket interface in the stainless steel brackets whereas at the enamel/bracket interface rather than bracket/adhesive interface in the sapphire brackets.
The results of the historical review of social and political realities in general show that the practical and procedural applications of social engineering as a particular activity primarily of the social and political characteristics of man and society emerged in modern Western societies before appearing in other societies, These results also show that the emergence of these practical reasons and their applications in the West has also seen the emergence of modern theoretical foundations there, which seems to be the usual and usual context everywhere and in most or not all areas of life. Since the social and political dimensions are intertwined in human life and are in full, comprehensive and lasting harmony, interest in this geometry h
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Summary
Praise be to God, Lord of the Worlds, and prayers and peace be upon the Master of the Messengers, Muhammad, and upon all his family and companions.
The circle of taboos in the Jewish Sharia is wider than other laws, as the Jews have severe and very complicated rituals in the matter of food, which may not be found among other people of other religions, as the dietary laws that specify foods and drinks forbidden in the Jewish Sharia include very diverse topics. The Torah specified all these laws with several texts
KE Sharquie, AA Noaimi, AA Zeena, IOSR J Dent Med Sci, 2015 - Cited by 5
Abstract
Balance is a psychological need and a requirement of importance as the individual seeks to maintain it. The research problem is summarized in the question: do students in the kindergarten department have a cognitive balance? The research aims to identify the cognitive balance of students in the kindergarten department and to identify if there are differences among students of the four stages according to the cognitive balance. The research community was limited to the students in the kindergarten department at the University of Baghdad / College of Education for Women and Al-Mustansiriya University / College of Basic Education and Iraqi University / College of Education for Women for the academic y
... Show MoreThe research entitled "the Iraqi Topics in International Arab Press" is an analytical study of two newspapers: Al-Arab and Al-Hayat published in London from September 1-30, 2013.
The Arab press is one of the cultural monuments Home stretches for culture and media of Arabs outside the Arab Homeland which made them international press targeting public Arab audience's not civil audiences in a particular country and formulating their contents on this basis taking into account intake affairs and issues that have been national or international.
Because of this international presence of the Arab press, these newspa
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It is no secret to anyone that the Koran is a speech to people, and how it is not a speech to humans is a home to them and suitable for their understandings, and the people of rhetoric mean great care has never been before in the division of the Koranic discourse, followed by linguists and science of the Koran. After reading the letter, I followed it in the Holy Quran, taking advantage of what was written by former writers in language and interpretation. Thanks to God, I have done what I wanted. Perhaps one of the most important reasons that led me to write my research and optional for this topic; is related to the Koran. So I started to develop the research plan, and divided it as I saw it, I started to pave the way, and then divided it
... Show MoreThe visual stimulus is the effective force in visual attraction that achieves visual and perceptual co-optation and is important in wooing the recipient, and many procedural processes in the design are interpreted on it as the visual stimulus achieves visual comfort and a sense of pleasure and gives (place) the interior space a transformation in its plastic structure as well as arousing attention through The kinetic rhythm and the formal diversity, which increases the possibility of breaking the routine and traditional constraints of design patterns through the coating and encapsulation of the vertical and horizontal levels . Thus, the research problem was launched based on the following question: What are the stimuli of the visual stimu
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Embedded advertisement constitutes a special kind of communication. As it performs many important roles such as giving information, highlighting the value of the product, and urging the target consumer to buy it by influencing his/ her behavior using an attractive manner of mind and conscience. Both cinema and television are the most prominent and powerful advertising media that enjoy the interest of all audiences and capture most of the advertising spending. As advertisers have paid attention to the importance of indirectly incorporating their products into content that the audience loves and is keen to follow, since the actual impact lies in the inclusion of the product within content that the audience appeals to. Hence, this leads to
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Of non-Muslim minorities In the Muslim community
The aim of the present research is to study the dissolution and transport process of
benzene as a light nonaqueous phase liquid (LNAPL) in saturated porous media.
Unidirectional flow at water velocities ranged from 0.90 to 3.60 cm/hr was adopted to study
this process in a three dimensional saturated sand tank (100 cm×40 cm×35 cm). This tank
represents a laboratory-scale aquifer. The aquifer was constructed by packing homogeneous
sand in the rectangular tank. The experimental results were used to characterize the
dissolution behavior of an entrapped nonaqueous phase benzene source in a three dimensional
aquifer model. The time invariant average mass transfer coefficient was determined at each
interstitial velocit