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.
(3)
The latest open commercial markets among countries, shift of capitals, and rise of mass economic, large international organizations, and international contracts leaded to a great increase of competition among countries for attracting capital for investments, specially among under developing countries which had bad economic situation, and which thinks that investment is the best solution to solve their old economic problems.
Developing small, and medium establishments in all economic sectors became the main economic force and natural resources for the development and growth of under developing countries. Small and medium establishments became the majority of any country establishments, and the past international experience shows t
... Show MoreThe information revolution، the new language has become one for all the peoples of the world through handling and exchange and to participate in all key areas (economic، cultural and scientific) and Accounting episode of this revolution has turned most of the traditional systems (manual) in companies to automated systems، this transformation in the regulations summoned from the auditors that develops their traditional examination automated systems so had to provide tools for auditing help auditors to keep abreast of developments and as a result there is no evidence checksum Local Private audited automated systems came search to provide evidence helps auditors for guidance as part of COBIT، which provides audit procedures Detailed inf
... Show Moreتبحث هذه الدراسة في المهارات االتصالية عند المحررين الصحفيين وترتيب أولويات امتالكها لديهم إذ تلعب المهارات االتصالية دورا مهما في نجاح عملية التحرير الصحفي للرسالة بكل أنواعها سواء كانت خبرا أو مقاال أو تقريرا أو تحقيقا أو حديثا ، وتتنوع هذه المهارات بين األساسية المتعلقة باالتصال والمالحظة القوية وسرعة التعبير وبين المكملة لها المتعلقة باللغة والمعنى واإلرسال واالستقبال ، وتأتي هذه الد ارسة لتركز الضوء
... Show Moreيهدف البحث الى تطبيق تزامن تصميم عملية انتاج معجون الاسنان في مصنع المامون التابع للشركة العامة للمنتوجات الغذائية مع نظام تكاليف الجودة المطبق في الشركة لتحقيق الميزة التنافسية. وتمثلت مشكلة البحث في أن الشركة عينة البحث لا تستخدم نظام تكاليف الجودة بالتزامن مع تصميم عملية إنتاج هذا المنتج لاغراض تحقيق الميزة التنافسية حيث تواجه منتجات الشركة منافسة عالية في الاسواق المحلية. إن الشركة تطبق نظام تكاليف الج
... Show Moreيهدف البحث التعرف على مستوى الوعي بتقنيات إعادة التدوير غير الميكانيكية التي يجري تطويرها حاليًا في قطاع "إعادة التدوير الكيميائي" الجديد لدى طلبة كلية التربية للعلوم الصرفة -ابن الهيثم. تكونت عينة البحث من (198) طالبا وطالبة من قسم الكيمياء للعام الدراسي (2021-2022) من أصل(250) أي (79%) من مجتمع البحث لدراسة الفصول الصباحية و(50) طالباً وطالبة من أصل (73) أي (68٪) من مجتمع البحث لدراسة الفصول المسائية لطلبة المرحلة الرابعة.وت
... Show MoreFive mixed primary schools from the district of Tikrit/ Salah al- din province
with a total of 100 male and female pupils and two ages(8-9 and 10-11 years),
were selected randomly to study the relationship between the breakfast meal and
the academic level, the socioeconomic situation, and the number of family
members. The study showed a positive linear correlation between the morning
meal, and academic level of students for both two covered ages, also showed a
clear impact between the development of family's socioeconomic situation and
their nutrition level. There were an increase in the percentage of pupils aged 8-9
years with a poor nutrition when they were belonged to a poor or medium
socioeconomic families,
Kurdish language multifunctional morphemes indicate the different functional morphological, syntactical, and semantic tasks of the morphemes. The present study discusses the multifunctional task of the Morpheme Le in Kurdish Language. The Morpheme Le has marginally been included in other studies, yet up to the present times, there has not been a research inclusively dedicated to thoroughly discuss and clarify its multifunctional aspects. The present study is divided into two chapters:
Chapter one discusses the theoretical aspect of chapter two that is entirely concerned with the practical aspect of the morpheme Le. The first part of chapte
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The writer of this messagewas Tajaddin Ahmad Abdulqader bin Maktoom Al-Qaisy Al-masry.
This message dealt with the biographies of twenty scientists of readers about Quran readings in Cairo . He comprehended these biographies and make it an appendage