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.
يعد تحليل السلاسل الزمنية من المواضـيع الهامة في تفسير الظـواهر التي تحدث خلال فترة زمنية معينة. ان الهدف من هذا لتحليل هو الحصـول على وصف وبنـاء أنموذج مناسب من اجل اعطاء صورة مستقبلية واضحة للسلاسل الزمنية المدروسة وان السلاسل الزمنية اهم الادوات المستخدمة في بناء وتقدير والتنبؤ بالظواهر المختلفة وان الاستدامة المالية هي الحالة التي تكون فيها الدولة قادرة على الوفاء بالتزاماتها الحالية والمستقبلية من غي
... Show MoreUse the accounting system of responsibility in assessing the performance of the company profit centers of the leather industry Given the importance of the profit centers of the General Company for Leather Industries, where a circle of activity that is accountable responsible for them (the director) about what is happening with costs and achieve revenues other words, the profit center is the beginning of an independent company with revenues and costs contribute to achieving the objectives of the company as a whole, which is to achieve profits, which means the comprehensive work of the centers of the need to evaluate its performance permanent depending on the conversion rates of the Interior. It was relied on the company's production
... Show MoreIt could be said that the essence of the “quota” is the state’s intervene as external power in bringing positive change for the benefit of the disadvantaged women and cultural minorities, and from the perspective that compensatory justice requires dealing differently with the different parties culturally and economically for the benefit of those deprived of them. Practicing of quotas merely, does not mean the full achievement of equality between cultural and sexual components in general, but it’s a big leap towards achieving this crucial goal, since the latter necessarily requires a range of legal and non-legal mechanisms aimed at empowering women and expanding their capabilities as a whole. On the other hand, in the absence of a
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This research interested to study the structural configuration in the square kufi script, as the kufi script is one of the oldest Arabic fonts, and this name was named according to the city of Kufa, so its types, forms, and designations were numerous, including the square kufic script, which was characterized by being a very straightforward engineering script based on the principle of squaring in building letters to form an engineering body that governs its construction of a set of organizational relationships and design bases according to an engineering structural system. The researchers identified the problem of his research with the following question: What is the Structural configuration in the square Kufic script?
Therefore, the
The harsh human suffering experienced by the Andalusians were a religious conflict and racist impact on all aspects of public life. The religious factor most important factors that determined the nature of the hostile relationship between the Andalusian and Castilian, Castile has sought to make them Christians by force through laws that deprived them of all their rights. In spite of the large number of those laws, the authority admitted inability to subdue the Andalusians to its will through the issuance of the final decree of expulsion.
The basic goal of human creation is worship, the Almighty stated: { I created the jinn and mankind only to worship Me} Al-Dhariyat 56. The basic worships by which we approach Allah Almighty are the praying and zakat, that they are significant because the praying and zakat mostly come together in numerous Qur’anic verses. Being the praying is a Physical worship while zakat is a financial devotion, they have many educational effects explained by the writer Muhammad Darwaza in his interpretations of these two pillars of Islam that he has chosen them to be the subject of this research
The Stressful Life Events consider one of the important thing in humans life in different period of life even school period, where it is deal with vital period of life which is the youth period that represent the hope and precious resources that nation depend on it in building her civilization, structure anddevelopment ,they are part from the present and whole future .As the great effect of stressful life event on humans , increase the need to put a program about psyching-up which consider one of the modren and effective programs.The aim of current search:1. Measure the level of stressful events at the junior high school studen
... Show MoreTo evaluate the toxicity of benzalkonium chloride in aquaculture, the hemato-serological indices of Nile tilapia Oreochromis niloticus are used as biomarkers. Following exposure to three concentrations of benzalkonium chloride BAC 0.1, 0.25, 0.50, and 1 mg/l (BAC1,2,3 and 4) in aquaria for two durations 21 and 42 days, the microbiological assay in fish aquaria, in addition to blood parameters were assessed. Except for the mean difference between BAC2 and BAC3 (P > 0.05) at 42 days, the mean values of the bacterial counts revealed a significant difference between all compared groups (0.05 ≥ P ≤ 0.01). Following exposure to the lower concentrations of BAC (1, 2 and 3), the main blood parameters of Oreochromis niloticus namely red bl
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Received several formats historical kings of old Babylonian era carries connotations military as it chronicled the kings of this era Sunni rule work, was in the forefront of those formulas taken from weapons-grade events have the history of years of their rule, and the keenness of the Kings on the industry that weapon and because it is dedicated to the goddess is the weapon of God, and which pulls the Goddess encouragement and an support them in their wars, they think the Iraqis ancient gods be carrying weapons at the forefront of their armies to fight the enemy with them as well as the receipt of a lot of alliances