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 main subject of this poem is a chance meeting between Baudelaire and unknown beautiful lady. Her presence represents the far-fetched, magnificent beauty. This beauty forms an aspect of idealism that takes its real existence and disappears immediately.
This emotional poem deals with the continuous despair that dates back to the Romantic age where it was a key topic; the passing woman embodies destiny. All this comes from constant experience and mad love through the poet’s view to a woman paving the way toward the unknown. Baudelaire, however, noticed this unknown through a passer-by that reflected the real and magical image of this unk
... Show Moreتعد الجامعات من أهم المؤسسات المجتمعية التي تؤثر وتتأثر بالجو الاجتماعي المحيط بها، فهي من صنع المجتمع من ناحية، ومن ناحية أخرى هي أداته في صنع قياداته السياسية، الفكرية، الفنية، والمهنية، ومن هنا كان لكل جامعة رسالتها التي تتولى تحقيقها، فالجامعة في القرن العشرين تختلف رسالتها وغايتها عن الجامعة في القرن الحادي والعشرين. ولكي تقوم الجامعة بدور أفضل في خدمة المجتمع وتحمل المسؤولية المجتمعية فلابد لها من وض
... Show Moreالملخص - يهدف البحث الحالي الى تعرف اتجاهات مدرسي ومدرسات المدارس الثانوية نحو التربية الجنسية والتعرف على اثر متغير الجنس (ذكور، إناث) في تكوين اتجاهات تدريس التربية الجنسية في التعليم - الثانوي فضلاً عن تعرف التطبيقات التربوية للتربية الجنسية في المدارس الثانوية ، إذ ان التربية الجنسية واحدة من أهم فروع التربية في الإسلام , وهي ذات أهمية في نشر الوعي الديني والصحي والتربوي والاجتماعي والثقافي في المجتمع
... Show More
Employing the social personalities (celebrities) in all fields (artistic, sports, media, etc.) is an important media and visual communication means of identification for the companies and institutions in order to convey the advertising idea in accordance with the creative, aesthetic and functional principles aimed at promoting products and gaining the symbolic value for the company. This study investigates the employment of social personalities in the commercial advertising design in order to pinpoint the importance of employing celebrities and their representation in the advertisement to convey the meaning that signifies the advertisement goal. Thus the question of the study is: "What are the mechanisms of employing celebrities in the d
... Show More
دور المواد النانوية في إعادة تصنيف تكاليف المنتج الصناعي الحديث
There are words that are described in certain words that are not described in other words, so the relationship between two words that accompany a habit is strengthened, which leads to the emergence of a conjunction or an idiomatic expression
Araştırmamın adı: Türkçe'de –madan, -meden Ulaç Ekinin Yazılışı ve Kullanılışıdır.
Ulaçlar, kişi ve zaman kavramı olmadan temel cümlenin yada yan cümlenin yüklemini niteleyen, cümlede genellikle zarf tümleci olarak görev yapan fiilimsilerdir. İkinci bir görevleri yardımcı fiillerle birlikte kullanılarak birleşik fiiller kurmak olan ulaçlar, cümlede bağlaç görevinde kullanılabilirler, ve birleşik cümleler kurabilirler. Bazı ulaç ekleri zarf, edat gibi kalıcı sözcük yapımında da kullanılırlar.
Bu araştırmada Orhun Türkçesi'nde başlayıp Türkiye Türkçesine kadar uzanan tarihi dönemlere ait eserlerden –m
... Show Moreعلى الرغم من أن الجامعات والمراكز والمؤسسات العلمية في الجامعات العراقية تزخر بالعديد من الكوادر والخبرات العلمية والأكاديمية المؤهلة علمياً وفنياً لانتاج البحوث العلمية والاشراف على طلبة الدراسات العليا، غير ان عملية انتاج الابحاث العلمية التطبيقية على وجه الخصوص تعترضها مجموعة من الصعوبات والمعوقات التي استطلعها الباحثين اما من خلال التجربة الشخصية, او من خلال استطلاعات اراء طلبة الدراسات العليا والب
... Show Moreاستهدفت هذه الدراسة تحليل واقع الاقتصاد العراقي على خلفية تحليل القدرة التنافسية بما يفضي الى وضع ملامح عامة لإستراتيجية بناء للقدرة التنافسية الوطنية للنهوض بالواقع الاقتصادي. وقد افترضت الدراسة ان الاقتصاد العراقي يعاني من اخفاقات شديدة في الاداء لا تتصل بطبيعته ولاتعتبر سمة اصيلة من سماته بل هي ظرفية وطارئة رغم وجودها منذ عقود.
ان حالة الوهن المرافق للفعاليات الاقتصادية تتصل بغيا
... Show More