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 current study aims at identifying of the differences of life quality level for the academic instructors at Omar Al-Mukhtar University / Libya according to the city variable that the instructor belong to ( Libya, Iraq, Egypt ), and also according to gender Variable (Male - Female),To achieve the aims of study ,the researcher chose a sample consists of (210) instructors ( 170 males and 40 females) from four colleges at Omar Al- Mukhtar University/ Darna . The researcher built the scale of life quality which consists of (42) items in last version . The researcher has conducted the validity and reliability of the scale. and by using Analysis of Variance via (SPSS program). The research reaches the following results : 1-The life quality o
... Show Moreان نجاح رياض الاطفال في تحقيق اهدافها يتوقف الى حد كبير على معلمة الروضة التي تزود الطفل بالخبرات ، فهي تمثل الام البديلة للطفل ، وتقع على عاتقها مسؤوليات نفسية واجتماعية واخلاقية نحو اطفال الروضة ، لدلك فان معلمة الروضة تقوم بعدة ادوار في رياض الاطفال ، فهي ممثلة لقيم المجتمع وتراثه التي تسعى الى غرسها في الطفل .
وعليه فان ليس كل من تتقدم للعمل في رياض الاطفال تصلح ان تكون معلمة ناجح
... Show Moreاتجهت دول العالم الى تسخير جميع الإمكانيات والخبرات والعلوم من اجل الوصول الى مستويات متقدمة في الرياضات المختلفة ويهدف التدريب الرياضي إلى إعداد اللاعبين إعدادا جيدا تكمن مشكلة البحث من خلال خبرة الباحثتان الميدانية ومتابعة تدريبات لاعبي المدرسة التخصصية كرة اليد فقد لوحظ هناك ضعف واضح في الأداء المهاري ولابد من تطوير أوجه الضعف لتحقيق مستوى انجاز افضل . ويهدف البحث اعداد تمرينات خاصة بأستخدام جهاز ا
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يهدف البحث الى التعرف على اثر استراتيجية نجمتين وامنية في تحصيل مادة الكيمياء عند طلاب الصف الثاني المتوسطولتحقيق هدف البحث تم اتباع المنهج التجريبي ذو الضبط الجزئي وتم تحديد مجتمع البحث بطلاب الصف الثاني المتوسط لجميع المدارس الثانموية والمتوسط التابعة لمديرية تربية الكرخ الثانية وتم اخنيار احد هذه المداس بصورة قصدية لتطبيق تجربة ابلبحث الحالي
This research dealt with the subject of auditing bank credit risks in accordance with international auditing standards and aims to develop procedures and design a credit risk audit program in accordance with international auditing standards and demonstrate their impact on the truth, truthfulness and fairness of financial statements and on their overall performance and continuity in the banking sector Its importance lies in relying on international auditing standards to assess and measure bank credit risk and its impact on the financial situation as well as the ability to predict financial failure. A set of conclusions have been reached, the most important of which is that the bank faces difficulties in measuring credit risk in accordance
... Show MoreAquatic Oligochaeta is an important group of Macroinvertebrates that has been very remarkable as bioindicators for assessing water pollution and determining its degree in water bodies. Hence, the idea of the current study aims at studying the impact of Baghdad effluents on the Tigris River by using oligochaetes community as bioindicators . For this purpose, four sites along the inside of Baghdad has been chosen. Site S1 has been located upstream, site S2 and S3 has been at midstream and site S4 at the downstream of the River.This investigation has used different types of biological indicators, including the percentage of oligochaeta within benthic invertebrates, which ranged from 49.2-51.28%. The highest percentage of the tubificid w
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Abu Al- Qasim Qa ,im Maqam is famous figure in political life of lranian; The life of Abu Al- Qasim Qa ,im Maqam is full of incidents and conflicts in the period of the expansion of foreign influence in lran Abu Al- Qasim Qa ,im Maqam has an important role in the history of Iran Modern political considered him one of the most prominent leaders to the unified Arabian nationalistic liberating Abu Al- Qasim Qa ,im Maqam raised in the history of the Qajar .
The article is final after making all the modifications. 2,259 / 5,000 يهدف البحث إلى قياس وتحليل الفجوة بين الواقع الفعلي لبنود التخطيط والدعم وفق المواصفة (IATF16949:2016) في مصنع البطاريات أحد مصانع الشركة العامة لصناعة وتجهيز السيارات، وكذلك التعرف على نقاط القوة والضعف لبنود التخطيط والدعم وفق المواصفة محل البحث. ينطلق البحث من حاجة الشركة العامة لصناعة وتجهيز السيارات إلى إتباع المعايير العالمية في صناعة السيارات والمنتجات المرتبطة بها،
... Show MoreThe aim of this research is to study and test the impact of the policy of open-book accounting as one of the cost management mechanisms in achieving the competitive advantage in Jordanian industrial public companies, to achieve the objectives of the study, a field study was conducted by surveying the views of a sample of the accountants of the Jordanian industrial public companies. Hence the arithmetical Means, the Standard Deviations, the Significant Value and the Simple Linear Regression are used to test the research hypotheses and to achieve the research goals. The results of the study showed that there is a statistically significant effect of the policy of open-book accounting as one of the cost management mechanisms in achieving the
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