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 Stressful Life Events consider one of the important thing in humans life in different period of life even school period, where it is deal with vital period of life which is the youth period that represent the hope and precious resources that nation depend on it in building her civilization, structure anddevelopment ,they are part from the present and whole future .As the great effect of stressful life event on humans , increase the need to put a program about psyching-up which consider one of the modren and effective programs.The aim of current search:1. Measure the level of stressful events at the junior high school studen
... Show Moreالانسحاب الاجتماعي بغض النظر عن العوامل المسببة له قابل للعلاج حيث وضحت البحوث العلمية إمكانية الحد منه باستخدام أساليب تعديل السلوك .
وهو نمط سلوكي شائع لدى معظم الفئات ان لم يكن كل فئات الاعاقة ،وينتج هذا النمط السلوكي الانسحاب الاجتماعي عن عوامل عدة فاذا الطفل يعاني من تلف في الجهاز العصبي المركزي فان هذا التلف قد يحول دون قيام الطفل بالنشاطات المطلوبة للعلاج. توضح البحوث العلمية ام
... Show MoreThe study relied on data about the health sector in Iraq in 2006 in cooperation with the Ministry of Health and the Central Bureau of Statistics and Information Technology in 2007 Included the estimates of the population distribution of the Baghdad province and the country depending on the population distribution for 1997,evaluate the health sector which included health institutions, and health staff, and other health services. The research Aimis; Measurement an amount and size of the growth of health services (increase and decrease) and the compare of verified in Iraq and Baghdad, and evaluate the effectiveness of the distribution of supplies and health services (physical and human) of the size of the population distribution and
... Show Moreشهد العصر الذهبي للإسلام تحول أساسي في مجال الزراعة عرف باسم "الثورة الزراعية الإسلامية" أو" الثورة الخضراء" أو "الثورة الزراعية العربية" ، وقد أتاح الوضع الاقتصادي العالمي الذي أسسه التجار المسلمون في جميع أنحاء العالم القديم ، نشر العديد من النباتات والتقنيات الزراعية بين أجزاء مختلفة من العالم ا
... Show MoreThe origin of this technique lies in the analysis of François Kenai (1694-1774), the leader of the School of Naturalists, presented in Tableau Economique. This method was developed by Karl Marx in his analysis of the Departmental Relationships and the nature of these relations in the models of " "He said. The current picture of this type of economic analysis is credited to the Russian economist Vasily Leontif. This analytical model is commonly used in developing economic plans in developing countries (p. 1, p. 86). There are several types of input and output models, such as static model, mobile model, regional models, and so on. However, this research will be confined to the open-ended model, which found areas in practical application.
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One of the Kurdish scholars who have research on the doctrinal issues of the author of this brief message that we are about to achieve; to bring it out better and in order to preserve the Islamic heritage, and revive what can be revived after being close to death by staying in libraries here and there, out of reach of hands, carrying dust Years of forgetting and marginalization, and this letter is the papers in the door of the divorce entitled his author "Iqdar al-dream for those who did not sign divorce commoner," and the name is evident the name, and the intention of the author through writing, where he wrote it to answer some of the knowledgeable among the public at the time So they decreed that there was no divorce from commoners D w
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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
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