ABSTRACT Background: Bracket rebonding is a common problem in orthodontics which may result in many drawbacks. The aims of this study were to evaluate the effects of application of two enamel protective agents “Icon†and “ProSeal†on shear bond strength before and after rebonding of stainless steel orthodontic brackets using conventional orthodontic adhesive and to assess the site of bond failure. Materials and methods: Fifty sound extracted human upper first premolar teeth were selected and randomly divided into two equal groups; the first time bonding and the rebonding groups (n=30). Each group was subdivided into control, Icon and ProSeal subgroups. The enamel protective agents were applied after etching (preconditioners). Shear bond strength before and after rebonding of stainless steel brackets were assessed using the Universal testing machine and the adhesive remnant index was used to find out the bond failure site using a stereomicroscope. Then the results were statistically analyzed using one-way ANOVA analysis test and T-test. Results: There were no significant differences in the shear bond strength mean values in either group or their corresponding subgroups. Forty percentage of the bond failure in ProSeal groups occurred away from the enamel where 75% of those were at the enamel protective agents/adhesive interface. Conclusions: The application of Icon and ProSeal did not compromise the shear bond strength and the application of the ProSeal may protect the enamel surface from trauma (cracks, chipping or detachment).
In many oil-recovery systems, relative permeabilities (kr) are essential flow factors that affect fluid dispersion and output from petroleum resources. Traditionally, taking rock samples from the reservoir and performing suitable laboratory studies is required to get these crucial reservoir properties. Despite the fact that kr is a function of fluid saturation, it is now well established that pore shape and distribution, absolute permeability, wettability, interfacial tension (IFT), and saturation history all influence kr values. These rock/fluid characteristics vary greatly from one reservoir region to the next, and it would be impossible to make kr measurements in all of them. The unsteady-state approach was used to calculate the relat
... Show MoreThe current research aims to evaluate liquidity (as an independent variable) to improve the bank’s profitability (as a dependent variable ), by the bank’s ability to maximize its profits from its business results without excessive bank’s liquidity, so that may affect negatively affects the bank’s reputation and it’s dealers confidence in facing their financial obligations. and this may lead trying to come out among other recommendations including contributing to obtain, the bank’s ability to achieve liquidity balance to maximize its profits. This research has been applied to the sample induced intentionally by choosing three Iraqi private banks. The researcher used financial indicators to assess the bank’s liq
... Show MoreBackground: With the start of the current century, increased the interest in the role of the adipose tissue derived substances that named adipokines in the inflammatory diseases of the human being including the inflammatory periodontal disease, but scientific evidences were not clearly demonstrate the association between these adipokines and periodontal pathologies. Materials and Methods: Forty two subjects male only with normal body mass index were selected for the study with an age ranged (30-39 years). Samples were divided into three groups of 14 subjects in each group based on clinical periodontal parameters; clinically healthy gingiva (group I), gingivitis group (group II) and chronic periodontitis patients group (group III), from whom
... Show MoreLean Six Sigma methodologies and Ergonomics principles are the main pillars of this work given their importance in the implementation of continuous improvement in assembly workstations design. When looking at the introduction of the Ergonomics that has been affected by the integration of the Lean and Six Sigma for improvements, it is necessary to understand why these methodologies belong to each other and how they can be handled in the industrial field. The aim of the work seeks towards the impact of analyzing the integration of the basics tools of Lean and Six Sigma that enhanced Ergonomics highlighted the importance of using the priority matrix in the selection of the priority criteria. Two models of a system based on
... Show MoreThe stress(Y) – strength(X) model reliability Bayesian estimation which defines life of a component with strength X and stress Y (the component fails if and only if at any time the applied stress is greater than its strength) has been studied, then the reliability; R=P(Y<X), can be considered as a measure of the component performance. In this paper, a Bayesian analysis has been considered for R when the two variables X and Y are independent Weibull random variables with common parameter α in order to study the effect of each of the two different scale parameters β and λ; respectively, using three different [weighted, quadratic and entropy] loss functions under two different prior functions [Gamma and extension of Jeffery
... Show MoreThis study aimed to provide a theoretical framework for the impact of the Turkish intervention in northern Syria and the extent of its impact on the relations between the two countries.
It also sought to answer the study's main question: What is the impact of the Turkish intervention in northern Syria on Turkish-Syrian relations during the period 2011-2019 ?.
In this study, the historical method, the descriptive method, and the systems analysis method were used, with the aim of arriving at an accurate and realistic understanding of the Turkish-Syrian relations.
The study reached a set of results, the most important of which was that the Syrian-Turkish relations are based on interests, and that all alliances and
... Show MoreThe degree of the woman’s satisfaction on clothing depends, to a large extent, on the body measurements. If clothing is very wide, it shows her enormous and if it is too tight it may draw attention to the defects of the body. It may also lead to the compatibility or incompatibility of clothing with fashion. Whatever the quality of the garment in terms of sewing and design, the costume which is not suitable for body size may affect the physical style negatively and may give the wearer an improper look. Clothing was carried out without measurements and did not use models (templates). The method of preparation affected the overall appearance because it often did not fit the shape of the body completely. Therefore, people thought in many w
... Show MoreGeodiversity is the variety within abiotic natural elements that include: rocks, minerals, landforms, soil types, and water resources. Recently ecologists and naturalists recognized that there is close relationship between geodiversity and ecosystems. Huwaiza marsh is located south eastern Iraq within Lower Mesopotamian plain. The main rock bed units which crop out north east of the studied area comprises many types of rocks: conglomerate, sandstone, mudstone, siltstone and claystone belong to Bai Hassan, Mukdadiya and Injana Formations. The general elevation of the area ranges around 5 meters (a. s. l.) near the marsh and increase northeast to more than 100 meters (a. s. l.) and the Land forms are: cuesta, oxbow lakes
... Show MoreThe aim of this novel native study was to determine the microbial contamination of broken and cracked imported commercial table egg in Baghdad markets and its economic effect. A total of 21510 commercial chicken table eggs were checked and surveyed from retail markets in different popular regions of Baghdad city during a year period from January 3rd to December 28th of 2018 and its microbial contamination were studied. Results revealed that significant differences (P<0.01) were appeared in the studied microbial counts during months of the study and significant differences (P<0.01) in the average counts between broken and cracked eggs and sound (not bro
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