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 بناء اية حضارة يمثل جهداً انسانياً يشترك فيه كل الافراد والمؤسسات ويستلزم حشد القدرات لاسيما النخبة التي توجه الجهود وتعمل على الاستخدام الامثل للموارد في اطار حركة منظمة للمجتمع تنتج وسائلها وتحقق اهدافها ، وان حركة التاريخ والواقع تظهر ان التدريسي الجامعي هو صفوة النخبة والجامعة هي بؤرة المعرفة المؤسسية . ( عبود 2008 : 12 ) &
... Show Moreصار لزاماً علينا بيان مفهوم المعنى الحقيقي للجهاد وبيان أفضل أنواعه ورتبه وتحديداً الجهاد الكفائي بين النظرية والتطبيق من حيث معناه العام وبجوانبه الفكرية والاجتماعية , والسياسية ,والاقتصادية , وإيماناً منّا بانتفاضة المرجعية العليا في إعلانها الجهاد الكفائي ضد العصابات الارهابية التي استباحت الدين والوطن فكانت بالفعل الهام إلهي جسد أروع مبادئ الاسلام في التضحية والدفاع عن الدين ومقدساته , وانبل القيم الا
... Show More
Post-structural critical studies highlighted the importance of studying the texts surrounding the text as an important part in the process of receiving and understanding texts, and although this topic was dealt with by the ancient Arabs and Europeans, interest in it appeared clearly after the appearance of Gerard Genet's book (SEUILS), which separated it Text Thresholds. Or what he called paratexte, and dealt with them with interest as he reads them on books. With the development of semiotic studies, interest in paratexte studies began in a broader way and in various literary and non-literary texts, including journalistic texts. And since specialized magazines are one of the press releases that enjoy their privacy in terms of topics and
... Show More
The early childhood is a dangerous period for the development of children
in their present and future life . It is important to design programs for the preschool
period .
These programs are relatd to the childs Personality and its integration .
The most effective stories and attractive programs for the child is the objective
stories which can develop his self-canfidence . Therefore the kindergarten
should participate in developing the childs personality and experience
because it is the most effective institute in the childs life .
The present study aims at finding out the effect of the narrative program in
the kindergartens . This has been done by investigating the truth of a number
of hypotheses to measure
Praise be to God, who is by His Power, righteous is done, and by His help to slaves who He likes, and God bless our Prophet Muhammad envoy mercy to the worlds, and upon his family and the good mates until Doomsday.After:
The fact that cursing is the far distance and expulsion from the mercy of God, curse has been proven by him - peace be upon him - for the many varieties in the Sunnah, with indication of a permit cursing the insurgents from the people of Qibla, either saying - peace be upon him -: (the believer never be as a curser ...), what is meant by those who do not deserve damnation of those not cursed God and His Messenger, and for this we must remove words cursing from the Dictionary of our words following the examp
... Show More1.Chapter I (systematic framework) which includes: the research problem and the importance of the research, the need for it, the goals of the research, the temporal &spatial boundaries, determine the terms and defined procedurally.2.Chapter II - the theoretical framework: It consists of three sections are:•The first topic:- the concept of references and experimentation in the theater. •The second topic:- the director of academic and experimentation in Iraq. Two paragraphs in this section came after the introduction, in first paragraph to talk about the Iraqi theater academic and experimentation, and in the second paragraph the researcher spoke about the academic director of the Iraqi and experimentation. 3.Chapter III - Actions -
... Show More
Whatever forms embodied in nature or in the product by forming elements, Kahadjom, fonts, and colors that characterized that her aesthetic and expressive values evoked to multiple indications of which are unequivocal, including what is iconic. Each one of these constituent elements of her form of extreme importance
أصبحت التنشئة الاجتماعية السليمة من أكثر الأدوات في التصدي لأوبئـة العنف والتطرف ومظاهرها المتفشية بصورة أو بأخرى في مجتمعاتنـا المعاصـرة عامـة باختلاف أيديولوجياته الفكرية ومعتقداته الدينيـة ومسـتوى نموهـا الاقتصـادي، وأصبحت بأشكالها المتنوعة معنية بترسيخ التعاليم الدينيـة السـمحة وغـرس القـيم الديمقراطية السليمة ومبادئ وقيم حقوق الإنسان في شتى مجالات الحياة الإنسانية، وهي أيضا تعد حجر الأساس من اج
... Show MoreThe investigative film is part of the documentary films and is considered one of the important films that have a high viewership by the recipient, which is of great importance in transmitting information and contributing to creating awareness of the community through the advertising function performed by the cinematic image, as the researcher addresses the concept of advertising and its development through the time stages. And advertising functions. Then the researcher dealt in his research with the cinematic technical elements that contribute to the success of the investigative advertising work, such as camera movements, music, sound effects, dialogue ... etc., which enrich the investigative picture with realism and the flow of informat
... Show More