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.
Abstract
Agricultural Bank is an important source of funding Specialist His role in lending to farmers, it imposes a great job in providing the necessary head for any developmental process in the agricultural sector money. The ACB of ancient Iraqi banks, and that because of its importance to the advancement of the national economy and contribute to the development and regulation of the economic sector through the support and the assignment of the Iraqi agricultural sector in various agricultural activities because it is responsible
for the process of granting agricultural loans to farmers bank.
The aim of the internal control in the agricultural banks to
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What makes the commercial advertisement distinct is the design structure which is built according to artistic and creative concepts and terms based on the visual and formal interdependence relationships to express the motives of the advertising idea, which is based in its action mechanism on the effective variables, some of which are related to the marketing aspect, and others related to the advertisement aspect. The major aspect is the functional and aesthetic variables, which are represented by the vocabulary of the advertisement area for the open spaces such as the street ads. Its promotional dimension is the active forces in the circulation of commodities and products. Therefore, there would be significant problems the designe
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The research aims to determine the impact of the use of teaching aids for the textbook and graphics teacher illustrations in the collection of historical information and retention, limited research on a sample of students in grade five numbered (68) primary school students of Benin in Baghdad governorate / Breeding Rusafa First, select the researchers of scientific material for students in research Topics are the first and second chapter of the Book of the Arab-Islamic history, set by the Ministry of Education.
And promising targets behavioral and according to the content of subject numbered (100) goal and lesson plans exemplary nu
... Show Moreعلى الرغم من تطور الدراسات التاريخية الخاصة بالمرأة بوصفها حقل معرفي مستقل بدأ منذ نهاية الستينيات من القرن الماضي .ونجاج الكاتبات والباحثات في العديد من بلدان الشرق الاوسط وشمال افريقيا في إعادة المرأة الى التاريخ، الا ان الكتابة التاريخية في العراق مازالت تعاني من نقص كبير في الموضوعات التي تناولت حياة النساء في الماضي. وما يزال الباحثات والباحثين ينظرون الى التاريخ على انه سردية للمعارك والحروب ويو
... Show MoreThe estimation of the parameters of Two Parameters Gamma Distribution in case of missing data has been made by using two important methods: the Maximum Likelihood Method and the Shrinkage Method. The former one consists of three methods to solve the MLE non-linear equation by which the estimators of the maximum likelihood can be obtained: Newton-Raphson, Thom and Sinha methods. Thom and Sinha methods are developed by the researcher to be suitable in case of missing data. Furthermore, the Bowman, Shenton and Lam Method, which depends on the Three Parameters Gamma Distribution to get the maximum likelihood estimators, has been developed. A comparison has been made between the methods in the experimental aspect to find the best meth
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ABSTRACT
Learning vocabulary is a challenging task for female English as a foreign language (EFL) students. Thus, improving students’ knowledge of vocabulary is critical if they are to make progress in learning a new language. The current study aimed at exploring the vocabulary learning strategies used by EFL students at Northern Border University (NBU). It also aimed to identify the mechanisms applied by EFL students at NBU University to learn vocabulary. It also aimed at evaluating the approaches adopted by EFL female students at Northern Border University (NBU) to learn a language. The study adopted the descriptive-analytical method. Two research instruments were developed to collect data namely, a survey qu
... Show Moreان الهدف من هذا البحث هو التعرف على أثر انموذج التفكير النشط في تحصيل طلاب الصف الثاني المتوسط لمادة العلوم و تفـكيرهم البصري. تكونت عينة البحث من (58) طالباً، يتوزعون بين مجموعتين احدهما تجريبية و اخرى ضابطة. تم اعداد اداتين مقننتين احداهما لقياس التحصيل والاخرى لقياس التفــكير البصري، وبعد تطبيق تجربة البحث والحصول على البيانات، التي تمت معالجتها احصائيا باستخدام البرنامج الاحصائي(SPSS)؛ كشفت النتائج عن تفوق
... Show Moreان الاستثمار في راس المال البشري االمتمثل بالقوى العاملة مرتبط بالتنمية المستدامة وان الانسان هو الثروة الحقيقية للأمم. والانفاق على التعليم تكون له انعكاسات ايجابية على الواقع الاقتصادي ووالاجتماعي والسياسي. ومن اجل تحديد العوامل المؤثرة على القوى العاملة تم تحليل العلاقة السببية (كرانجر) بين القوى العاملة و عدد الخريجين والسكان وعدد الجامعات والناتج المحلي الاجمالي والانفاق على االتعليم العالي ، بوجو
... Show Moreيهدف البحث إلى استقصاء أثر دراسة طالبات كلية العلوم للبنات في جامعة بغداد لمقرر التلوث البيئي في تنمية اتجاهاتهن البيئية، وذلك من خلال التعرّف على النمو في المستوى العام لاتجاهات الطالبات البيئية والكشف عن الفروق الإحصائية في اتجاهاتهن قبل وبعد دراسة المقرر.
وقد تألفت عينة البحث من(50) طالبة من طالبات قسم الفيزياء / الفيزياء الطبية المرحلة الأولى في كلية العلوم للبنات- جامعة بغداد. اعتمدت ا
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