Background: This study was conducted to assess the effects of various beverages on the shear bond strength of light-cured orthodontic composite used to bond stainless steel orthodontic brackets on human teeth and to determine the site of bonding failure of this material. Materials and Methods: Fifty extracted human premolars were selected and randomly divided into five equal groups each with 10 teeth according to the beverage type (Control, One Tiger, Milk, Green tea and Coffee). After bonding, the teeth were immersed in specific beverages for 5 minutes twice daily with equal intervening intervals then washed and stored in distilled water at 37º C for the reminder of the day. The process was carried out for 30 days. The samples were then tested for shear bond strength using Tinius-Olsen testing machine with a crosshead speed of 0.5mm/minute. For adhesive remnant index, the enamel surface and bracket base of each tooth were inspected under magnifying lens (20X) of a stereomicroscope. Results: Milk, coffee and one Tiger energy drink reduced the shear bond strength of the light-cured composite significantly unlike the green tea. The predominant site of bond failure was between the bracket base and the adhesive leaving the composite on the tooth rather on the brackets base. Conclusions: Orthodontic patients should be instructed to reduce the intake of acidic and fatty beverages to prevent debonding of the orthodontic brackets.
The question of challenging the validity of the parliamentary membership of some members of the House of Representatives in some parliamentary systems will appear for many reasons, including the failure to observe constitutional or legal texts or the regulations organizing the electoral process that are intertwined in its procedures and stages, such as the lack of conditions for nomination that were organized by law to allow the nomination for parliamentary membership or marred defects The procedures of the electoral process led to the demolition of its integrity, which guarantees the selection of the parliament that is able to delegate to the real author
... Show MoreInternational bankruptcy is a legal system for those who take trade as a craft and stop performing their obligations of an international character as a result of a defect in their financial position. Legislative jurisdiction in cases of international bankruptcy is one of the most important topics of international bankruptcy by researching the position of national and comparative legislation by determining the applicable law such as the law of the court that hears the dispute or the law to which the attribution rule refers.
In the beginning, the study examined and analyzed the obligations and rights of the government partner in the partnership contract, one of the most important of which was to provide an appropriate environment that includes an organized legal framework that allows the private partner to enter into investment fields, and ensures that he obtains returns that make him desirable from the users of his services and products, and that administrative procedures are conducted in a legal way that enables the contracting partner to obtain the licenses and approvals necessary to establish and operate the project easily and smoothly, in addition to the stability of the legal legislation on the status it was in at the time of the conclusion of the cont
... Show MoreThe stok marker is a welcoming space for expense work as a broker who practices securities trading for the benefit of its clients, and since the broker as a legal person is a bank , so this research was necessary to review the banking governance rules that apply to the brocker, both at the level of appointment and selection, and what are the conditions that They must be present in the personality of the mediator and his assistants, or the application of the rules of banking governance either directly or indirectly.
The Concept of the Constitution and the most Important of Human Rights
The international ranking of the quality of universities is one of the important topics that have taken a great deal of attention that is related to the scientific status at the local, regional and international levels.Quality means a set of characteristics and features of a product or service related to its ability to meet a specific need by making the product or service suitable for use. The quality of education represents the degree that meets a set of educational characteristics specified in accordance with the standards of institutional accreditation of educational indicators in achieving the quality of the educational product, and the educational instit
... Show MoreIdentify the effect of an educational design according to the repulsive (allosteric) learning model on the achievement of chemistry and lateral thinking. The sample consisted of (59) students from third-grade intermediate students. They were randomly distributed into two groups (experimental and control), and the equivalence was done in (chronological age, previous achievement in chemistry, intelligence, lateral thinking). The (30) students from experimental group were taught according to the instructional design, other 29 students from the (control) group were taught according to the usual method. Two tests done, one of them is an achievement test consisted of (30) items of the type of multiple choice, the other was a lateral think
... Show MoreChronic Kidney Disease (CKD) is a public health problem and many studies support the link between kidney dysfunction and cardiovascular events. Aldosterone has been shown for decades that a plasma aldosterone concentration is elevated in CKD. Whilst, Osteoprotegerin (OPG), after its capacity to protect bone, also osteoprotegerin is elevated in patients with chronic kidney disease (CKD), where it could predict the deterioration of kidney function, cardiovascular, vascular events and all-cause mortality. On the other hand, fibroblast growth factors (FGFs), in patients with CKD, its levels seem to increase progressively as kidney function worsens. The aim of the present study is to assess the correlations between serum osteoprotegerin
... Show MoreEach sport has its own energy requirements that differ from the energy requirements of other sports, and a different method is used in each of them, so the trainer must first rely on the principle of privacy in training first, that is, privacy according to the working energy system, that is, he defines the controlling energy system In that event, and how the muscles use the available energy to perform according to the energy production systems. As we find the serving skill is the first volleyball skill with which the team starts the match in order to be able to gain points directly, through knowledge it turns out that there is a weakness in the skill performance, especially the skill of serving and being The key to victory for volle
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