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.
The research aims to shed light on the obstacles that hinder the use of taxpayers' commercial books covered by provisions of the amended commercial book-keeping system No. 2 of 1985 and ways to address these obstacles. On this basis, the main null hypothesis was formulated that there is no statistically significant relationship between the obstacles to the adoption of the commercial books and taxable income.
The research data were collected on the base of three applied case studies of registered taxpayers in the General Commission of Taxes, GCT, together with the use of a questionnaire distributed to a sample of taxpayers ( companies ). The collected data were analyzed, the result were presented and the hypothesis was
... Show MoreIn this work, prepared new ligand[3- (1H-indol-3-yl) -2- (3-(4- methoxybenzoyl)thiouereido) propanoic acid](MTP) has been synthesized by reaction of 4-Methoxybenzoyl isothiocyanate with tryptophane(1:1), The ligand was characterized by elemental microanalysis C.H.N.S, FT-IR, UV-Vis and 1H,13C NMR spectra, Some transition metals complexes of this ligand were prepared and characterized by FT-IR, UV-Vis spectra, conductivity measurements, magnetic susceptibility and atomic absorption, From obtained results the molecular formula of all prepared complexes were [M(MTP)2] (M+2 =Mn, Co, Ni, Cu, Zn, Cd and Hg), the proposed geometrical structure for all complexes were tetrahedral except copper complex has a square planer geometry around metallic ion
... Show MoreAbstract Background The aim of this study was to identify differences in oral cancer incidence among sexes, age groups and oral sites over time in Iraqi population. Methods Data was obtained from Iraqi cancer registry, differences and trends were assessed with the Wilcoxon matched-pairs signed-ranks test and Regression test, respectively. Results In Iraq from 2000 to 2008, there were 1787 new cases of oral cancer registered, 1035 in men and 752 in women. Cancer at all oral sites affected men more than women. The Tongue other (ICD-02) is the most frequent site follow by lip (ICD-00). Conclusion The decrease in the percent of oral cancer incidence in Iraq not compatible with the high percent of exposure to the risk factors, Iraqi cancer regis
... Show MoreCommunity peace is achieved in law-based states Constitutional institutions with competence and powers, and otherwise that peace is shaken and begins to collapse. The movement of individuals and groups in the State is regulated by law The law and its proper application without selectivity or exception, and then the sense of equal opportunity and equal rights grows every citizen looks at his spouse, what he has, and when he is unbalanced, a sense of frustration and stealing of rights is generated Societal peace suffers from the shocks of instability and what is reflected in the surrounding environment. Instead of production, demolition takes place, which impedes the achievement of the required peace.
... Show MoreThis study was conducted to determine the side effects of dexamethasone n some physiological and immunological criteria, which included, Measuring sugar level, liver (ALT, AST , LDH, Total protein) and kidney function (urea, createnine), total and differential count of W.B.C,CRP, TNF-α ,IL6,IL10. thirty rats were divided into two groups (15\ rat). G1: This group was considered negative control injection with normal saline, G2: This group was injected with 2 mg\kg dexamethasone. The results showed a significant increase in the level of enzymesALT, AST and sugar levels and decreased level of total protein in the group treated with the drug, also showed, a significant decrease in the total number of W.B.C an
... Show MoreThis research aim to present theoretical and philosophical framework regards topic of intellectual capital readiness in Iraqi universities. That is, by using strategic map in balanced score card of Norton and Kaplan (2004). This research discusses theoretical content for three main aspects reflect in its nature elements of intellectual capital readiness in organizations. This includes human capital readiness, information capital readiness and organizational capital readiness. To clear each element, the authors relay on mechanism to determine gape per element of intellectual capital elements.
The objective of all planning research is to plan for human comfort and safety, and one of the most significant natural dangers to which humans are exposed is earthquake risk; therefore, earthquake risks must be anticipated, and with the advancement of global technology, it is possible to obtain information on earthquake hazards. GIS has been utilized extensively in the field of environmental assessment research due to its high potential, and GIS is a crucial application in seismic risk assessment. This paper examines the methodologies used in recent GIS-based seismic risk studies, their primary environmental impacts on urban areas, and the complexity of the relationship between the applied methodological approaches and the resulting env
... Show MoreThe childhood of the most important stages throughout the human and which have been more vulnerable to various factors surrounding it and with the scientific and cognitive development in all fields surfaced many psychological phenomena that play a large role in influencing children and their behavior trends is the susceptibility of the lure of psychological phenomena which plays a major role in the social attitudes of individuals it may not be predictable so that individuals vary in between them in terms of vulnerability Balasthoa You do this only _bl that the same individual at different influenced Balasthoa different depending on the positions and this was research to achieve its objectives and that are known:
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