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.
The research aims to verify the Role of Internal Auditing in Assessing the Risks of Strategic Operations (Acquisition) and then reflect on management decisions. Since all corporations wish to expand, growth and domination of the market may expose them to multiple risks that lead to failure. The research assumes two main hypotheses. First, there is no role for internal audit in evaluating the strategic operations (acquisition). Second, there is no relationship between internal auditing in assessing the risks of strategic operations (Acquisition) and management decisions. The data was collected by using a questionnaire distributed to a group of private bank employees. The statistical analysis regarding research rejected the two hyp
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Abstract :
The research aims to study the basic concepts of banking productivity and discuss different approaches to study what ends to identify the most important possible standards applied to measured within the Iraqi banking environment as well as research into the causes of low and high Iraqi banking productivity and identify possible treatments to curb those reasons as to ensure the rise. And in line with the research problem, which states what is the level of productivity and what are the causes of decline and the rise in private banking research sample individually. And what the Iraqi private banks and what is the relationship between performance and the impact of productivity change in the perform
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In the present work, heterojunction diode detectors will be prepared using germanium wafers as a substrate material and 200 nm tin sulfide thickness will be evaporated by using thermal evaporation method as thin film on the substrate. Nd:YAG laser (λ=532 nm) with different energy densities (5.66 J/cm2 and 11.32 J/cm2) is used to diffuse the SnS inside the surface of the germanium samples with 10 laser shots in different environments (vacuum and distilled water). I-V characteristics in the dark illumination, C-V characteristics, transmission measurements, spectral responsivity and quantum efficiency were investigated at 300K. The C-V measurements have shown that the heterojunction were of abrupt type and the maximum value of build-in pot
... Show MoreThe aim of this study is to highlight the relationship between competitive intelligence and Entrepreneurial Performance by centralizing the strategic vigilance of a sample of civil faculties in Baghdad. The sample of the study was targeted at 10 Iraqi civil colleges, which consisted of (133) members of the faculty council of the faculties, the search data was collected using the questionnaire form as the main research tool. The results showed that the correlation and influence of competitive intelligence and strategic vigilance in the Entrepreneurial Performance, as well as the role of strategic vigilance as an intermediate variable between competitive intelligence and Entrepreneurial Performance.
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This study aimed at revealing the degree of availability of standards of word problems in mathematics books for the first three grades of the basic stage in Palestine. For this purpose, the researcher prepared an analysis tool and a list of criteria consisting of two areas: linguistic formulation and mathematical content. Every area had seven items. The results of the study showed that the third-grade mathematics book has the highest degree of availability of the standards with 85.75%, and then came the second-grade mathematics book with 83.12%. Finally, the first-grade mathematics book came with 80.13%. In the light of the previous results, the researcher recommended to develop the language of word problems, to take into account their i
... Show MoreThe present study aimed to impact Strategy mental map in the acquisition of geographical concepts at the fifth-grade students in the literary geography classes. To achieve the objectives of the research formulated researcher null hypothesis (no statistically significant difference at the level (0.05) between the average scores of students who Adersna using a mind map, and who Adersna using the method usual in the acquisition of concepts geographic fifth grade literary). Has chosen researcher design Altjeribeachtar researcher Design The partial adjustment for both experimental and control groups Pachtearlakedzab concepts. The sample Seateetmthel graders secondary schools under the Directorate General of Educational Baghdad Rusafa II has c
... Show MoreBreast cancer is the most repeatedly detected cancer category and the second reason cause of cancer-linked deaths among women worldwide. Tumor bio-indictor is a term utilized to describe possible indicators for carcinoma diagnosis, development and progression. The goal of this study is to evaluate part of some cytokines and biomarkers for both serum and saliva samples in breast cancer then estimate their potential value in the early diagnosis of breast cancer by doing more researches in saliva, and utilizing saliva instead of blood (serum and plasma) in sample collection from patients. Serum and salivary samples were taken from 72 patients with breast cancer and 45 healthy controls, in order to investigate the following
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The laser micro-cutting process is the most widely commonly applied machining process which can be applied to practically all metallic and non-metallic materials. While this had challenges in cutting quality criteria such as geometrical precision, surface quality and numerous others. This article investigates the laser micro-cutting of PEEK composite material using nano-fiber laser, due to their significant importunity and efficiency of laser in various manufacturing processes. Design of experiential tool based on Response Surface Methodology (RSM)-Central Composite Design (CCD) used to generate the statistical model. This method was employed to analysis the influence of parameters including laser speed,
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Walter Lippmann, speaking about man, says : ” Gradually he makes for himself a trustworthy picture inside his head of the world beyond his reach. “. This means that the picture, whether it was good or bad, it doesn’t happen for nothing, but rather for intentional purposes. Some orientalists make their judgements even before getting to the place concerned with the study.
The mental image is one of the most misused terminology, although the world today has become the world of image, it witnessed the disappearance of the theories that used to consider the media as a reflective mirror for society, also it was confirmed that the media creates what varies from reality and sometimes completely different from reality. The image of
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