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.
This paper deals with one of important topics that serve the art movement music, which is looking at the stairs of Arab music in the process of reaching to the directory musical on the subject of so-called (Photo by stairs music) and that by comparing the method used previously and the proposed rules reached by the researcher and received the patent invention, the method is easier for the musician and the author in a directory of peace Arab music when used on grades and half grades voice, and to achieve its objectives researcher dealt with the problem that is determined by the multitude of stairs leading Arab and the difficulty of keeping its catalog of music, and for being an anchor and pillar of the music was taken up and put her impor
... Show More
السياسة في الفلسفة الاسلامية : الفكر السياسي عند الفارابي
(1)
התמצית השניות היא התורה שנזכרת כי המוצאים בלשון הערבית וכך בלשונות השמיות אינם הבטויים בעלי האותיות השלושיות , אלא בעלי שתי אותיות . לפי כך אפשר להשיב השורשים השלושיים לשורשים השניים . וכל אות שנאספה בשורש שׁניוני, יהיה לפי חוק ההתפתחות הלשונית , הוספות תחילית , תוכית , סופית , עם השארת החיבור המשמעתית בין השׁניוני והשׁלשׁי כמו היא ממושכת בין השׁלשׁי והרביעי ומה שרבה ההוספות . השרשים השניים מוצאים הם: אות וה
... Show MoreThe study of cultural identity and its data in the designer’s work is considered a cultural nature to highlight the cultural identity and link it to the national culture of their country and society. It provides a reflection and translation of the society’s culture, traditions, social and economic dimensions, the natural environment, and scientific phenomena. Within meanings translated into a variety of methods, including expressive and realistic, which defines the designer’s relationship with his society and the national culture of his country and his connection with the civilization of the country.
The research problem came with the following question: What are the data of cultural identity in the work of designer David Gent
The intellectual and revolutionary movements that have emerged since the beginning of the second half of the first century of the Islamic era did not appear suddenly, but must have preceded by a social consciousness, multi-forms, in the forefront of class awareness and religious awareness, and awareness was more painful, Of the society of the Arabian Peninsula - before Islam - feel it and suffer from it, a sense of injustice and tyranny, oppression and humiliation, and the destruction of dignity as well as poverty and hunger, and the injustice of tribal laws, and tyranny of each other and the tyranny of their heads on the tribes members and families belonging to this tribe or hill
The role of the Abbasid Caliphate in strengthening the business with the Indian subcontinent and development. Came upon Baghdad and the shift of succession to Iraq in the forefront of efforts made by the Abbasids to revive the trade with Eastern countries, given that the commercial was targeted among other factors,'s location in Iraq amid the ancient world among the countries of Turk
مشكلة البحث واهميته:-
اخذ موضوع العولمة قدراً وافياً من الاهتمام سواء على المستوى الاكاديمي او على مستوى اجهزة الاعلام والرأي العام ومختلف التيارات السياسية والاقتصادية والاجتماعية ، فلا يخلو أي لقاء اقتصادي او سياسي او اجتماعي من الحديث عن العولمة اذ نشرت العديد من الابحاث والدراسات وعقدت الكثير من الندوات والمؤتمرات لدراسة العولمة وبيان اثارها ولعل ذل
... Show Moreتمت دراسة سرعة الاخلاف في النوع Branchiura sowerbyi وعلاقتها بدرجات الحرارة حيث لوحظ ان قابلية هذه الديدان على اخلاف الحلقات الجسمية التي تحوي على الخيوط الغلصمية تكون اسرع من قابليتها على اخلاف الحلقات الجسمية الاخرى وبنسبة موت اقل خاصة في درجة حرارة ( 20 ± 3 ) م°.
الامن الجماعي في اسيا .. بقلم : لونيك فرو وار
The followers of philosophical lesson in Iraq discover steps and important stages through which the country had passed in , since the control of this thought in Arab Islamic civilization until recent time as well as touch the important changes that had happened on it