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.
Research problem: the problem of the current research can determine the dimensions of answering the following question - What is the impact of the use strategy summaries tribal collection and retention in the second grade students in the middle of history?
The importance of research: In order to achieve the desired education and access to educational goals required, and to address all the challenges facing the educational process, so you may need to use methods and different educational methods in the teaching of social history, particularly, of those methods and modalities to adopt strategies tribal in teaching, has chosen researcher summaries tribal style, which is one of the strategies of goo
The research deals with the lyrical introduction in the commentary of Tarfa bin al-Abd as a formative system characterized by flexibility and richness of imagination, which achieved a formative treatment and a unique construction within the structures of the structural and semantic language. I dealt with the poetic verses represented by the lyrical introduction as a formative hypothesis, basing its goal on a methodological framework distributed on the problem that was summarized by the following question: Is it possible to look at the poetic pattern within the pre-Islamic poem / hanging blinking as a model, in its plastic dimensions and to identify the stylistic treatment that achieves the formation space within the poetic text. The rese
... Show MoreThe advertising has emerged as an effective force and an effective instrument upon with all organizations and companies depend on achieving their goals. In additional to the need to use promote sales, The nature and objective of advertising go beyond the scope of specific personal communication to a broader and more effective range for consumers from multiple groups and combination play need to use as well as the need to use means of communication than com convey the message more professional, The coincides with the rapid and remarkable development of all different media technologies and as much as possible social networking sites including mobile phone companies. The advertising has emerged as an effective force and an effective instrum
... Show Moreتعد البرمجة الخطية عاملاً مؤثراً وفعالاً في عملية صنع و إتخاذ القرار عندما تكون الموارد متاحة أو متوفرة لكي تعطي أهدافاً معينة ، وتكمن البرمجة الخطية في حل وتقييم الانشطة أو الفعاليات عند تطبيق إحدى أدواتها وهي الطريقة المبسطة العامة ، التي يكون فيها الحل مقبولاً (ممكناً) ويجب التوصل الى الحل الامثل عندها تسمى بالطريقة المبسطة الاولية أو يكون الحل فيها أمثلاً ويجب التوصل الى الحل الم
... Show MorePeaceful coexistence is not seen as a new topic of secretions of modern civilization, a requirement to solve the problems of our era or one of the indications of urgent immediate needs, rather, tolerance is considered basis for building a state. Therefore, we can touch on the principles and basics of tolerance in the Holy Qur’an, the speeches of the Messenger (may God bless him and grant him peace) and his hadiths, and the principle of brotherhood that he established
The research aims at the following:
- Identifying the level of internal quantity efficiency in Medical colleges, University of Baghdad by determining the level of productivity for one group for the total batch according to sex variable (males and females). Procedures of the study
The researcher used the descriptive and analytical method has been used by following them up enhanced by flow indicators of students for one session depending on special statistical data analyss .
The results are as follows:
- The Faculty of Medicine were higher productivity scholarships for one year and two years of schooling, as well as the highest in the efficiency of the Faculty o
... Show MoreIn this article, the partially ordered relation is constructed in geodesic spaces by betweeness property, A monotone sequence is generated in the domain of monotone inward mapping, a monotone inward contraction mapping is a monotone Caristi inward mapping is proved, the general fixed points for such mapping is discussed and A mutlivalued version of these results is also introduced.
Britain found itself at the end of the nineteenth century in front of many obstacles within Europe, it is to hold the coalition Russian Franco in 1894, and what form of threat to the interests of Britain in its colonies outside Europe, as well as the development of other European countries in military and economic aspects such as Germany and the United States and others. As she was defying the fleet of Britain, Germany, and the last has a naval fleet was able to protect all the way Britain and its colonies throughout the nineteenth century
أن أزدياد أعداد الطلبة في معظم دول العالم ، والتوسع في التعليم العالي ، أدى الى أستيعاب أعداد كبيرة في المؤسسات التعليمية من حملة الشهادات العليا الماجستير خاصة والدكتوراه ، وأن برامج الدراسات العليا وضعت لأعداد باحثين مختصين في مجالات عدة منها التدريس وما يتطلبه من مهارات مختلفة ، فأن قسماً منهم ليست لديه المعرفة النظرية والتطبيق العملي والمهارات اللازمة لأستخدام طرائق التدريس والتقنيات التربوية أث
... Show MoreThe audit committee has received considerable attention from international institutions and researchers as a result of financial failures and the collapse of major international companies, especially cases of manipulation and misinformation in the financial statements, due to the role played by one of the mechanisms of control of economic entities to increase disclosure and credibility of information published, In overseeing the preparation of financial reports, following up the internal auditing functions, supporting the external auditor and enhancing his independence, and strengthening the shareholders' confidence in the economic entity. The two researchers prepared the applied side of the research by applying a proposed model based on
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