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.
تعد عملية اتخاذ القرارات الستراتجية للموازنة الراسمالية احدى المعضلات التي تواجه منظمات الاعمال عند القيام بتخصيص ، او اعادة تخصيص مواردها الاقتصادية النادرة على أفضل استخدام ، والسبب يعود الى ان هذا النوع من القرارات ينطوي على صعوبات متعددة ومختلفة نظراً لندرة الموارد من ناحية الاستخدامات البديلة المتنافسة على هذه الموارد من ناحية اخرى .
كما ان تنفيذ المشروعات الراسمالية يحتاج الى تمويل ضخم ومدة زم
... Show Moreقراءة في تأسيس الدولة العراقية 1921 الاهداف والنتائج
اثر المحددات الخارجية والداخلية في بناء الدولة العراقية
واقع ومستقبل الصراعات الدولية والاقليمية في البحر الاحمر
The relation ship between Syria and Lebanon is a distinguished one
because of the cultural social geographic and historical common factors. So
that, Syria considers that Lebanon has a stratieyical depth for it, especially its
conflict with (Israel) does end and parts of its lands still under the occupation
of the Zionist thus, any conflict in Lebanon between parties and ethnics
groups could be considered an important influence on the bases of the Syrian
policy. Moreover the issue of Palestine which is considered the central issue
for Syria and Arab as whole. In addition to some of the political movements
that happened in the region itself. It could be said that Syrian interference in
Lebanon has a positive infl
Iraq is highly dependent on international markets to provide food for its residents. As imported food prices are highly dependent on crude oil prices in global markets, any shock in oil prices will have an impact on food consumption in the country. As a result, it is essential to study the demand for imported food at every time period. To the best of our knowledge as researchers, as not even a single study is available in the literature, this paper is considered the first to study the demand for imported food groups in Iraq. Therefore, the main objective of this research is to estimate demand elasticities for several imported food categories in Iraq. This study uses an Almost Ideal Demand System model to analyze the demand for imported f
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Praise be to God, prayer and peace upon our master Muhammad the Messenger of Allah peace be upon him mercy, gift, and grace, and rendered his family and the good righteous is followed until the Day of Judgment. After: The Koran
دور الحكومات في بناء الدولة ضمن اطار الدستور
Fraud Includes acts involving the exercise of deception by multiple parties inside and outside companies in order to obtain economic benefits against the harm to those companies, as they are to commit fraud upon the availability of three factors which represented by the existence of opportunities, motivation, and rationalization. Fraud detecting require necessity of indications the possibility of its existence. Here, Benford’s law can play an important role in direct the light towards the possibility of the existence of financial fraud in the accounting records of the company, which provides the required effort and time for detect fraud and prevent it.
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