Background: The demand for better esthetic during orthodontic treatment has increased nowadays, so orthodontists starting using esthetic arch wires, brackets and ligatures.Tooth colored brackets were introduced in different types of materials. Sapphire ceramic brackets are one type of esthetic brackets and their color stability remains the main concern for the clinicians and patients at the same time. The present study design to evaluate the effect of three different staining materials (pepsi, black tea and cigarette smoke) on the stainability of sapphire ceramic brackets bonded with three types of light cure orthodontic adhesives which include: Resilience, Enlight and Transbond. Materials and Methods: The sample consisted of three hundred sixty sapphire brackets. The brackets were divided according to bonding materials into three groups each group consist of one hundred twenty brackets, then each subgroup farther subdivided into four groups according to the material they were immersed (distilled water, black tea, Pepsi and cigarette smoke) with thirty brackets each, then Each group with ten brackets farther subdivided according to time interval of immersion in each media into three groups one day, seven days and fourteen days at 37°C in the incubator.A UV-Visible spectrophotometer (Shimadzu, UV -1800) was used to perform a light absorption test. Results: ANOVA and LSD post Hoc tests were used to identify the significant effects of the staining materials at a significance level P ≤ 0.05.It was found that the immersion time gradually influenced the color stability of the adhesive materials with sapphire brackets with the highest activity observed at fourteen days interval. The brackets bonded with Resilience light cure adhesive are the most type affected by staining materials, then followed by the brackets bonded with Transbond and finally the brackets bonded with Enlight light cure adhesive. For the staining materials it was found that the cigarette smoke is the most powerful staining material, followed by tea and finally pepsi. Conclusions: From the above result we can conclude that the type of adhesive must take in consideration when the esthetic brackets have been used.
This paper studies the effects of stiffeners on shear lag in steel box girders with stiffened flanges. A three-dimensional linear finite element analysis using STAAD.Pro V8i program has been employed to evaluate and determine the actual top flange stress distribution and effective width in steel box girders. The steel plates of the flanges and webs have been modeled by four-node isoparametric shell elements, while the stiffeners have been modeled as beam elements. Different numbers (4, 8, and 15) for the steel stiffeners have been used in this study to establish their effects on the shear lag and longitudinal stresses in the flange. Using stiffeners reduced the magnitude of the top flange longitudinal stresses about 40%, but did
... Show MoreThe present study aimed to investigate the possible protective effect of cafestol against doxorubicin-induced chromosomal and DNA damage in rat bone marrow cells. Wistar
Albino rats of both sexes were administered cafestol (5mg/kg body weight once
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A critics ,Shugaa Muslim Al-Aany, has specific critical principles in his branch
classifications for the type of the novel that is linked with its sources and what is adopted
of critical approaches and curriculums. The novel by its type as a literary one has
occupied Al-Any's critical importance very much ,he has divided it historically according
to its historical development ,the impact of dr.Abd Al-Muhassen Tha Badr's divisions on
Al-Any cannot hidden.
In his speech about the origin of novel and story art generally , Al-Any becomes
between the acknowledgement of the affect of Al-Mgma in rising of this art and denied its
affect at last. He has classified the novel also as a stylistic classification:(an impression
The "Corona" pandemic that strikes the world has cast a shadow over contractual obligations, whether between individuals or companies, and emergency accidents and force majeure circumstances have a direct impact on them. Here, the legislation intervenes and sets the legal mechanisms to restore the obligations to their equal status and achieve the economic balance of the contract. Health crises are among the material facts whose effects are reflected and their features can be monitored on legal relations in general and contractual relations in particular, including the extent of the impact that this pandemic can have on the obligations that arise within the framework of a contractual relationship, which can be talked about in my theory Force
... Show MoreThe Incentives legislation aims to raise the efficiency of job performance of all kinds through optimal investment of human resources and their capabilities to raise or increase and production influence and provide distinguished and creative services such as The Incentives Law of Productive Ministries Employees No. 20 of 1993 and instructions issued by ministries and relevant Facilities regarding incentives for their affiliates based on provisions Public Companies Law and the instructions of the Higher Education Fund issued by the Ministry of Higher Education and Scientific Research. The human element is the most unstable and complex element of production as it is characterized by a set of feelings and emotions that is expresses
... Show MoreThe purpose of this research is to identify
the effect of the translation of poetic poem into an artistic picture in the achievement of retention among fifth grade students.
In order to verify the research goal, the first two hypotheses were determined. There are no statistically significant differences between the average scores of the experimental group who study (according to the technical picture) ) And the control group (according to the traditional method of art education) at the level of significance (0,05). The second is that there are no statistically significant differences between the average of the experimental group who study (according to the technical picture) and the control group who study (On According to the trad
Hypertension is identified as one of the most significant risk factors for cardiovascular diseases (CVDs). There is growing evidence showing that oxidative stress plays a major role in hypertension. Increased production of reactive oxygen species and decrease bioavailability of antioxidant have been demonstrated in experimental and human hypertension. The present study was directed to determine the beneficial effect of the antioxidant vitamin C in patients with essential hypertension treated with the calcium channel blocker (amlodipine) or with the angiotensin converting enzyme inhibitor (enalapril). Ninety six patients (50 females and 46 males) with essential hyp
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Background: Small cardamom or green cardamom is the dried fruit of the tall perennial herbaceous plant, Elettaria cardamomum Maton belonging to the family Zingiberaceae. The major use of small cardamom on world wide is for domestic culinary purpose and in medicine. This study was conducted to test the effect of small cardamom extracts on Mutans streptococci and Candida Albicans in comparison to 0.2% chlorhexidine gluconate and de-ionized water in vivo. Materials and Methods: Mutans streptococci and Candid Albicans were isolated, purified and diagnosed according to morphological characteristic and biochemical test. In this experiments, the effect of control agents and small cardamom extracts as a mouth rinses was tested on the saliva
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Let R be a commutative ring with identity and M be unitary (left) R-module. The principal aim of this paper is to study the relationships between relatively cancellation module and multiplication modules, pure submodules and Noetherian (Artinian) modules.