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.
ان الداسات القرانية تعد من الدراسات المتعلقة في اللغة العربية لانها تتعلق بدراسة جانب من جوانب اعجاز القرأن الكريم لذلك قمت بدراسة جانب من جوانب اعجاز القران الا وهي لفظة اكل
ان الهدف من البحث هو تقويم منهاج الفيزياء للصف الاول الثانوي في الجمهورية اليمنية
Advantage of the science of management for a lot of other sciences vitality and openness to the rest of the science and knowledge of the various branches fields, and at the same time, overlapping and intermingling majora between the various branches of administration and specialties, and based on this fact, the idea of this research to come out of one of the important topics with two topics of vital in the field of strategic management, namely patterns Strategic Command, and the effectiveness of senior management teams. I've seen the science of management, particularly in the field of strategic management, large shifts and changes, especially in the last two decades, as the RPR Strategic Management rich field of research and the emergenc
... Show Moredance that reflect deferent sides from life human , in this search ensure for the causation can the expressionistic dancing be development acting actor in Iraqis theatre ? so this search concept of section one composed of the search problem , and important the search and need it , aimed the search , lines search it composed of the lines time , place , and lines subject , and the searcher ended this section with practical terms . Section tow – theatrical lines form that composed of part one the dance kinds: the expressionistic dancing, is very important in analyses the symbol .
... Show More
خليفة بن خياط بن خليفة الشيباني ألليثي العصفري البصري، أبو عمرو، ويعرف بشَبَابه، الفقيه، المُحدَث، الأديب، المؤرخ، النسَابة، وهو سليل أسرةِ اشتهر أبناؤها بالعلم، وأنجبت عدداً من العلماء الأفاضل، الذين عرفوا في ميادين مختلفة، فالجد والأب والحفيد، علماء محدَثون، وبرزوا في علوم عدة ، كان متقناً وعالماً بأيام الناس.
اهتمام العلماء العرب بالحروف مبينين معانيه موضحين مقاصده
يعد الذكاء الاصطناعي من العلوم الحديثة التي ارتبطت بالإنسان منذ العقود الخمسة الماضية، ولتصبح السياسة الرقمية الاقتصادية جزءاً لا يتجزأ من المجتمع، لكونها خرقت أغلب مجالات حياة الانسان. وهذا ما شجع صانعوا السياسات التكنولوجية الجديدة في التفكير بكيفية توظيفه لخدمة مصالحهم الاقتصادية العُليا، بغض النظر عن بذل الجهود للتفكير في مصالح الانسان الاقتصادية وتنظيمهم ومراقبة الذكاء الاصطناعي التوليدي. لقد أيقن
... Show Moreتحديات العولمة للهوية العربية و دور الجامعات العربية في مواجهتها
هدف البحث إلى التعرف على اصالة الذات فضلاً عن التعرف على الفروق في اصالة الذات بين الطلبة على وفق متغير الجنس (ذكر – انثى) والتخصص الدراسي (علمي – انساني) والمرحلة الدراسية (أول- رابع)، تألفت عينة البحث من (140) طالبا وطالبة من طلبة جامعة الموصل-كلية التربية الاساسية، وتم تطبيق مقياس البحث - مقياس (اصالة الذات) وهو (من إعداد الباحثة)، وقد اسفرت نتائج البحث عن: - إن طلبة الجامعة يتمتعون بأصالة الذات. - عدم وجود فروق في
... Show More