Laser etching may be an alternative to acid etching of enamel and dentin. Several characteristics of irradiated dental hard tissues have been considered advantageous, microscopically rough surfaces without demineralization, open dentinal tubules without smear layer production and dentin surface sterilization. The aim of this study is to determine and compare histology the microleakage in class V cavity restored with a light cured composite after conditioning the samples(tooth surface) with 1-acid etching, 2-Q-switched Nd:YAG Laser etching and finally 3- acid and laser etching. Materials and methods: Twenty four non carious human extracted teeth were used in this study. The samples were equally grouped into four groups of six teeth each. A class V cavity was prepared. In group I, tooth surface was etched with a 37% phosphoric acid gel. In group II, the tooth surface was conditioned using a pulsed Nd:YAG Laser alone with a wavelength of 532 nm. The parameters were of pulse energy 60 mJ, pulse repetition rate 6Hz and energy density was 0.48 J/cm2. In group III, the tooth surface was treated with Nd: YAG Laser and then was etched with phosphoric acid. In group IV, the surface was treated with 37% phosphoric acid then irradiated with Nd: YAG Laser; with the same parameters and concentration mentioned in group I and II. The samples immersed in 1% basic fuschin dye to mimic the normal stains in oral cavity and the sections were examined by a stereomicroscope and the readings were scored. Results: The results showed that group IV, in which the surface was treated with 37% phosphoric acid and then irradiated with Nd: YAG Laser) recorded the least microleakage of the four groups, where group III, in which the tooth surface was treated with Nd: YAG Laser and then was etched with phosphoric acid)recorded reasonable results better than group I (group I tooth surface was etched with a 37% phosphoric acid gel) or group II , in which the tooth surface was conditioned using a pulsed Nd:YAG Laser alone) Conclusion: The use of Q-switched Nd:YAG laser in etching the tooth surface was so effective that it can be used in treating or conditioning the tooth surface to enhance bonding and the best parameters among the tested samples were pulse energy of 60mJ, pulse repetition rate of 6Hz and energy density 0.48 J/cm2.
The poverty in the developing countries is output to under development as we consider welfare, where as when the poverty disappear that produced be the general development . Historically, in our countries, the underdevelopment is the result of colonialism period and what is associated with it of transferring the surplus abroad and the disorder of production structure. And at the present time, the poverty is reproduced and aggravated in the last years as a result of many internal and external reasons.Today, poverty is associated in many forms with the poverty previously.
المقدمة
اشكالية الطائفية السياسية في العراق بين الاستمرارية والانكفائية
The global globalization the world is experiencing has enabled international actors—states, international governmental and non-governmental organizations, such as liberation movements, international social movements, and even terrorist organizations—to use cyber power to achieve their goals. Therefore, this study discusses the impact of information power on the domestic environment of the United States.
This paper shed light on castles in Iraq through Othman reign to know their sorts , and studying planning concentrating on the nature of architecture , this is a serious trying to study and important side of military architecture in Iraq with its reasons of building them which had related with political, military , social ,and economical circumstances of country .
Land beyond the river has the attention of historians, especially travelers and geographers of its various regions under the Islamic Arab state. They antedate the social and economic aspects, including agriculture, industry and trade in their products and goods to other countries and urbanism, which we will address in our research
يستهدف البحث التعرف على اهمية التعلم باللعب لاطفال رياض الاطفال وانعكاساتها على تعديل سلوكهم، حيث ان اللعب هو دنيا الطفل المليئة بالمتعة والاستطلاع والاستكشاف، كما ان اللعب بالنسبة للاطفال يمثل لهم الحياة بكل ما فيها من معنى.
وفي الوقت نفسه اللعب هو وسيلة من وسائل الضبط والتوجيه للتعامل مع سلوك الاطفال، فمن خلال اللعب نستكشف النبوغ والتفوق منذ وقت مبكر، حيث ان التعلم باللعب يمثل حاجة حيو
... Show Moreالمنطق منهجا نقديا - دراسة في قراءة الشكل الجمالي كتاب (المنطق منهجا نقدياً – دراسة في قراءة الشكل الفني) يهتم الكتاب بدراسة التصورات المنطقية في الفنون التشكيلية وهو يقع في اربعة فصول خصص الاول منها لبيان المنهجية والفكرة العامة عن علاقة المعرفة بالقواعد الفكرية والقواعد المنطقية موضحا ذلك في (مدخل عام) وتعلق الفصل الثاني بالمفاهيم المنطقية وما كتبه علماء المنطق في عرض شامل ومكثف تناول فيه المؤلف مفهوم ال
... Show MoreReceipt date:08/26/2020 accepted date:9/8/2020 Publication date:12/31/2021
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The research entitled (Moderation in Omani External Political Behavior 1970-2020. contained introduction and two sections conclusion and recommendations. The introduction included a general overview of the topic, and the importance of the political behavior o
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What linguists mentioned about the infinitive and its use in the linguistic levels of speech, whether with its verb, or what was mentioned in the difference between the infinitive and the noun of the source, are matters that are related to the phenomenon of hearing in speech, a need necessitated by the nature of the linguistic law and its connection with the Arabic dialects, which proceeded in the linguistic levels to form Phenomenon inherent in the use of the source and the name of the source
This poem is regarded an important Harmonized structure in modern and Contemporary Culture to achieve aqualitative poem Comported with the other cultural structures inorder to discover the ego and aspiration in shaping distinctive voices.
The Iraqi poetry is affected tangibly by this poem because of the intellective vaccinating between Iraqi and Arab poets ingeneral and western cultures in particular as a result of the tranplahin movement and other important means.
The modern poet wood to ask some important characters to enrich his technician text inspite the fact that this is not a new way in Arab poetry but it takes avarant – criented to become outside the limits of rigid description within ongoing kinematic structure to be in