Background: With the increasing demands for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding.The present study was carried out to compare the shear bond strength of metal bracket bonded to porcelain surface prepared by two mechanical treatments and by using different etching systems (Hydrofluoric acid 9% and acidulated phosphate fluoride 1.23%). Materials and Methods: The samples were comprised of 60 models (28mm *15mm*28mm) of metal fused to porcelain (feldspathic porcelain). They were divided as the following: group I (control): the porcelain surface left untreated and glazed, group II (Diamond bur group): the porcelain surface was treated with fine diamond bur at speed of 350000 rpm for 20 seconds, group III (Red stone bur): the porcelain surface was treated with coarse red stone bur at speed of 8500 rpm for 20 seconds. Each group consists of 20 samples, then each group subdivided into two subgroups; one treated with acidulated phosphate fluoride 1.23% and the other subgroup treated with Hydrofluoric acid 9 % with silane coupling agent. Results: The result of this study revealed that there was very high significant difference among all tested groups and the highest shear bond strength was for diamond bur group with HFA and Silane (8.67 MPa), the 2nd highest strength was for control group with HFA and Silane (7.52 MPa), the 3rd was (7.38 MPa) in red stone bur with HFA and Silane, the least shear bond strength values were obtained for subgroups treated with acidulated phosphate fluoride gel 1.23%. Conclusions: The most reliable procedure for bonding orthodontic brackets to the porcelain surfaces is through the surface treatment combinations of mechanical roughening by using diamond bur, 9% Hydrofluoric acid and Silane coupling agent application.
هدفت الدراسة الى التعرف على درجة اتخاذ القرار وعلاقتها ببعض المهارات الأساسية الهجومية بكرة السلة للطالبات ، اذ يعد اتخاذ القرار قدرة الفرد على التوصل لحل مشكلة اعتراضية أو موقف محير، وذلك باختيار حل من البدائل الموجودة أو المبتكرة، وهذا الاختيار يعتمد على المعلومات التي جمعها الفرد حول المشكلة وعلى القيم والعادات والخبرة والتعليم والمهارات الفردية وتمتاز لعبة كرة السلة بوجود الكثير من المواقف المتغ
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A field study was conducted in Al-Khalis district, Diyala Governorate in 2019 to test the sensitivity of three varieties of pepper to the population density of the whitefly B. tabaci, Anaheim pepper, Aleppo and local variety, and the results showed that the Anaheim variety was the most infested with the whitefly density 4.08 whitefly/ leaf and then the local variety 2.7 whitefly/ leaf. The lowest population density was 1.25 whitefly/ leaf of Aleppo variety. Variety Aleppo also recorded the lowest percentage of whitefly infection B. tabaci of 39.22%, but not have significant differences in the percentage of whitefly infestation, as it reached 53.64% and 54.85% for the Anaheim and local varieties, respectively. The resistance of variety Alepp
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The aim of this research does not deal with evaluation occurs at any points in the design of the plan alternatives themselves or formulation of goals and objectives. The aim of this research is that test and evaluate the fully alternatives. We can therefore state as the principle that evaluation of alternative plans must be based on attempts to show how far each plan satisfies all the objectives are expressed as specification of the performance of the urban and regional system. The planner can submit the result (as in the traditional way) for each alternative, with particular reference to the weighting of objectives. The summery result can be presented and the preferred plan indicated that with largest index of Goals-achievement.
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Expansion the engineering consultancy offices in the universities of Iraq, about (14) offices, leading to increas the competition between them, especially after the great trends of Iraqi government agencies to use the academic experiences and their efficiencies in general, due to non-existence of the engineering qualification in the government institutions to do the engineering designs ,supervision of projects and other engineering works which are practicing by the engineering consultancy offices in order to get the best performance of the work.Within this serious competition, needing a specific approach to enable government agencies to choose the optimal and alternative consultancy office to meet specific project and not rely on cronyis
... Show MoreTwo locally isolated microalgae (Chlorella vulgaris Bejerinck and Nitzschia palea (Kützing) W. Smith) were used in the current study to test their ability to production biodiesel through stimulated in different nitrogen concentration treatments (0, 2, 4, 8 gl ), and effect of nitrogen concentration on the quantity of primary product (carbohydrate, protein ), also the quantity and quality of lipid. The results revealed that starvation of nitrogen led to high lipid yielding, in C. vulgaris and N. palea the lipid content increased from 6.6% to 40% and 40% to 60% of dry weight (DW) respectively.Also in C. vulgaris, the highest carbohydrate was 23% of DW from zero nitrate medium and the highest protein was 50% of DW in the treatment 8gl. Whil
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AW Ali T, Journal of the Faculty of Medicine, 2015 - Cited by 3
This paper deals with aesthetic and a sitting position in contemporary Iraqi sculpture and studied this situation, an analytical study to reveal how to employ them in aesthetically pleasing work of art has been research in a sitting position to a lack of technical library for such research, this study includes four chaptersChapter I contains the research problem and its importance in terms of the released address and its objectives in the detection of this situation, how to employ the HDL research is to detect how the aesthetic of the Employment sit position and limits Find business is bronze and stone-dimensional exclusively carried out from 2000 to 2009 AD.Chapter II included the Framework theory and previous studies and with three Inv
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This present paper aim at knowing the process of evaluating the training program that could be applied in Maysan Health office for it significance and importance in field of management and vocational staff preparations of high scientific experience in different fields of Health. The society of research includes staffs working in Maysan Health Office , of specialists , dentists, pharmacists, laboratories, nursing and administrators. Their number is 100 employees, the researcher has designed questionnaire by depending on "Kirkpatrick" for assessing the training . The researcher has used thorough survey and has entailed 90 questionnaire,
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