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.
Literary heritage and its employment in poetry has received the attention of poets, and they have employed it in their literary texts, as this employment is one of the oldest phenomena in Arabic literature, that the inspiration of this heritage in texts through the overlap of their texts with previous texts, and no poet neglected the importance of this employment. The ancient critics determined that the poet’s special culture is represented in the necessity of taking from the ancients, and this taking is the reference from which the poet draws his material and idea, as well as to clarify the meaning and its significance
This research paper sheds light on the stages of Atmospheric forecast in Iraq. It was found that atmospheric forecast in Iraq has passed through several successive and interrelated historical stages. Each stage is characterized by special methods of prediction that are different from other stages. The oldest stages used astronomy to forecasting cases of cold , heat, flood and drought
يهدف هذا البحث الموسوم بـ (المنهج النقدي في كتاب الرجال للنجاشي(ت 450هـ )إلى تسليط الضوء على حياة النجاشي ومكانته العلمية والكشف عن منهجه النقدي في كتابه المذكور.
من المتفق عليه أن هناك طريقا واحدا لنشر الثقافة والقضاء على الجهل هو التعليم .ولعل أبرز ماشهدته مدينة بغداد من تطور هو ظهور المدر سة ومن ثم إنتشارها بشكل كبير وفق المفهوم الحديث مما أثرفي عموم الحياة اليومية ، ومن ضمنها التعليم العالي .إن الإستقرار من أهم ماتحتاجه الجامعة للقيام بواجباتها ولايأتي الإستقرار إلا بالإستقرار الذي يضمن لنا أن تكون الجامعة بعيدة عن ما قد يستجد من الأهواء و النزاعات.
This study sheds light on female entrepreneurship in Palestine, and explores the reasons behind its relative weakness as compared with men, and with female entrepreneurship in other countries. This study aims at proposing effective policies and doable measures to enhance female entrepreneurship. Achieving this objective will carry significant impact on employment and economic growth at large, and increase women’s economic participation, scaling up their independence, and demonstrating their skills and abilities, and putting women on an equal footing with men. Furthermore, entrepreneurial activity has increasingly become one of the key drivers of economic development. An increased rate of entrepreneurial activities among women,
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There are many researches deals with constructing an efficient solutions for real problem having Multi - objective confronted with each others. In this paper we construct a decision for Multi – objectives based on building a mathematical model formulating a unique objective function by combining the confronted objectives functions. Also we are presented some theories concerning this problem. Areal application problem has been presented to show the efficiency of the performance of our model and the method. Finally we obtained some results by randomly generating some problems.
The current research aims to provide a conceptual and applied frame on the subject of multi- level analysis in the research of business administration. The research tries to address some of the problems that befall the preparation of research and studies at the Arab level and local level, where the unity of theory and measurement and analysis, as well as clarify the various types of conceptual constructs and give researchers the ability to distinguish different models related to the level of analysis. On the other hand, this research provides an example of
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This aim research of this discussion impact of investment in human capital dimensions (training, education, knowledge management, skills development) and its components (knowledge, skills, abilities, value) with the Office of the Inspector General's staff - Ministry of Culture in Iraq, has depended questionnaire as a tool in the collection data and information ,subjected to a measure of validity and reliability, and distributed to a sample of (63) individuals were distributed in positions (director, director of the Division of employees) have been analyzed data search using ready-statistical software (SPSS) the used hypothesis testing and correlati
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- Aim of the current research is to know the impact of guided discovery strategy sports communication skills among students in first grade average in mathematics.
- , Consisted sample of (58) a student from a school Baghdad Rusafa, divided in two groups, one experimental studied according to strategy discovery The second group studied the traditional way, the researchers built search tool (test communication skills sports), and using a number of statistical methods including : -
- Test (t - test) was used to independent samples to examine the match Mediterranean experimental and control groups and tested Levin (Leven - test
The representations of the Holy in Christian painting Art represents a penalty of eternal relationship between any human society and sacred representations and forms that he belives in what is characterized by its clear tendency to knowledge and aclear focus on the spiritual experience that make up the human relationship with holy spirit and essence. Search has ment to study the forms of its presence in the art work of the middle ages.Research involved four shapters .first chapter includes research problem which centered around the following question;what is holy ? whats its represetations in Christian painting? And the importance and need of the study .and the goal of research and definitaions of the terms of research.Second chapter con
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