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.
المستخلص
يهدف هذا البحث إلى تصميم ومكننة نظام متطور لتقويم جودة العملية التعليمية للجامعات العراقية، باعتماد مدخل الجودة، ومكننة نظام معلومات قادر على توفير البيانات بالخصائص المطلوبة التي يمكن الاستناد إليه في اجراء عملية التقويم على وفق النظام المقترح.
اعتمد البحث على أسلوبيّ دراسة الحالة والدراسة التطبيقية، للوصول إلى النتائج ا
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This research deals with study and analyze the industrial buyer behavior and identified its objectives by determine the nature of selection the members of the purchases committees and determine the role of the purchases committees to provide requirements of the educational and scientific process and knowledge Impact of the factors ( environmental , organizational , social , and individual ) and positions of the purchase in the behavior of the members of the purchases committees and starts the importance of research in it helps university administrations in the correct choice for the members of the purchases committees and gives a picture of professional conduct professional who is supposed to b
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The goal of current researcher to know the impact of strategic Jigsaw in the collection of hypertext and geographic operations of science students at the preparatory stage And that by checking the following 1.There is no difference statistically significant at the significance level 0.05 between the experimental group students who were studying strategy Jigsaw and between the control group students who studied in the usual way traditional degrees in the average achievement in the subject of geographical 2.There is no difference statistically significant at the significance level 0.05 between the experimental group students who were studying strategy Jigsaw and between the control group students who studied in the usual way traditional av
... Show Moreتناولنا في بحثنا أحد اساليب البرمجة الخطية وهي الطريقة المبسطة لتقدير معلمات انموذج الانحدار الخطي عن طريق اختيار دالة الهدف التي تعمل على تقليل الحد الادنى لمجموع الاخطاء الناتجة من تقدير المعلمات بطريقة المربعات الصغرى الاعتيادية ( OLS) حيث سيتم في الطريقة المبسطة ( simplex) فرض قيود على نفس الاخطاء نفسها بهدف تصغيرها الى اقل ما يمكن للحصول على تقديرات افضل لمعلمات انموذج الانحدار الخطي . على اساس ان طريقة المرب
... Show MoreThe production function forms one of the techniques used in evaluation the production the process for any establishment or company, and to explain the importance of contribution of element from the independent variable and it's affect on the dependent variable. Then knowing the elements which are significant or non-significant on the dependent variable.
So the importance of this study come from estimating the Cobb-Douglas production function for Al- Mansoor General Company for Engineering industries in Iraq during the period (1989-2001)
To explain the importance which effects the independent variable such as
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Facial recognition has been an active field of imaging science. With the recent progresses in computer vision development, it is extensively applied in various areas, especially in law enforcement and security. Human face is a viable biometric that could be effectively used in both identification and verification. Thus far, regardless of a facial model and relevant metrics employed, its main shortcoming is that it requires a facial image, against which comparison is made. Therefore, closed circuit televisions and a facial database are always needed in an operational system. For the last few decades, unfortunately, we have experienced an emergence of asymmetric warfare, where acts of terrorism are often committed in secluded area with no
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The issue of the survival of the Ottoman Empire during the nineteenth century, a controversial topic in European diplomacy, was what was called the "Eastern Question" containing the fate of this country and its regions sprawling one of the hottest topics in the diplomatic major European powers of that century
The research aims to study and assess the effectiveness of preventive measures banking for the reduction of money laundering based on the checklist (Check list), which have been prepared based on the paragraphs of some of the principles and recommendations of international and Money Laundering Act No. 93 of 2004 and the instructions thereto, to examine and assess the application of these measures by Gulf Commercial Bank, which was chosen to perform the search.
I've been a statement the concept of money laundering in terms of the definition and characteristics, stages and effects of political, economic and social as well as the nature of banking supervision in terms of the definition and the most important
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The creative arts in general and the theatre in specific represent man's rushing and carving for freedom, goodness and beauty, and the relation between creativity and freedom has always been fluctuating following the censorship pressures of all types and shapes the political, religious and social. Since the theatre is the closest and more touching creative art to the problems of the society of numerous types and levels and it was and has always been playing an enlightening role in shedding light on what the societies experiencing with crises and problems in all directions. The theatre, thus, derives the essence of existence from life, through topics concerned with what the human being is. It seeks to be the real witness and partne
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