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 research discussed the freedom of Iraqi women in the thought of Dr. Nazeeha Al-Dulaimi.
Those human societies, which based on pluralism and cultural diversity, can be handled with completely consciously، when converting the contradiction to integration and the collision to coexistence and the transition from intolerance to tolerance. This diversity in communities make individuals differ acconding to the following:
1- The requirements of human nature.
Thethesis of theresearch is to deal with relations between Russia and Yemen after 2011.That relationwas significant in different fields, historic, economic, strategic and cultural ones. There are mutual interestsbetweenRussia and Yemen, especially with the economic development and growth in Russia as an important partner to Yemen.Their has to an a great deal of progress in different types of relations, where as they were only partner in military relations. The studywasclassifiedintoto three sections: the first section dealt with strategic importance of Yemen to Russia. And second section dealt withthe military factor between Russia and Yemen. While the third section dealt with the economic factor between Russia and Yemen. In addi
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تتباين القراءة والكتابة من ناقد لآخر تبعا للموضوع الذي يتناوله، وطبيعة المادة، والمكونات المعرفية التي تؤسس فهمه، فمنهم الناقد التقليدي الذي يتبع السائد في نقده للمادة الفنية اما بالموافقة والتبني أو بالمغالطة والقدح، ومنهم الناقد المقلد الذي ينتخب اتجاها غربيا يرغب في تطبيقه على جزء من النصوص التي انتقاها، ومنهم الناقد الذي يتبع أفكاره ويدمجها مع النص ناقد مختلف يبحث في ما يذلل من قواعد، يحلل ويشرح وفقها
... Show Moreנסיון השביה בספרות המלחמה העברית יותר מביעה למרחק בסיכולוגי אצל הלוחם העברי ,
אני מעמד מול הנושא הזה , כי אני כותב בהמחקר הזה נסיון השבוי והשפעתו בציור הדמות אצל
הסופר '' יזהר סמילנסקי ) 1916 – 2006 ( " , סופר עברי יליד ישראל , נודע בכינוי תספרותי '' ס .
יזהר " מחשובי היצורים בספרות דור הפלמ''ח בפרט ובספרות העברית והכללית . חתן פרס ישראל
לספרות לשנת ) 1959 ( – כידד הגשם דמות ה '' אני '' וה '' אנחנו '' לגלה את ספל השבוי היחיד כ
LA TRANSGRESSION CHEZ RIMBAUD Lecture de I' aspect de Transgression dans Marine
По мнению ученых, исследующих современные деривационные процессы, „начиная со второй половины XX в., активизируются новые социолингвистические и коммуникативные факторы”, определяющие специфику современного словотворчества в ряде типологически близких славянских языков [Нещименко 2010: 39]. В результате возросшего влияния масс-медиа на коллективное сознание носителей языка, на существующий вербальный
... Show MoreThe Feedback Concept has been spread as an organized trend for scientific research since it has a significant importance for human behavior and how it has been directed and controlled by the individual, feedback has numerous definitions but the simplest definition is; feedback is the information received by the individual from the output of his behavior, In addition to the mutual relationship between the individual and the stimulation that provide him with the basic information by the biological control of his behavior, Since feedback cannot be accomplished without receiving information from the inner and outer environment, the biological and physiological information become the ma
... Show MoreWhat linguists mentioned about the infinitive and its use in the linguistic levels of speech, whether with its verb, or what was mentioned in the difference between the infinitive and the noun of the source, are matters that are related to the phenomenon of hearing in speech, a need necessitated by the nature of the linguistic law
مشكلة البحث وآهميته :
تعد مرحلة ما قبل المدرسة من المراحل شديدة الأهمية في نمو الأطفال في هذه المرحلة تمتد رغبة الطفل في التعرف على العالم المحيط به ثم تتطور أنشطته لتصبح أكثر عمقا وأتساعا فتتضمن البيئة البعيدة عنه ، هذا فضلا على أن 50% من التنمية الذهنية للطفل تتشكل في السنوات الأربع الأولى من العمر وأن القراءة هي إحدى المكونات الأساسية التي تعززهذا الجانب من التنمية .
( أبو
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