Background: evaluate the effects of three different intracoronal bleaching agents on the shear bond strengths (SBS) and failure site of stainless steel and monocrystalline (sapphire) orthodontic brackets bonded to endodontically treated teeth using light cured orthodontic adhesive in vitro. Materials and methods: Eighty extracted sound human upper first premolars were selected, endondontically treated and randomly divided equally (according to the type of the brackets used) into two main groups (n = 40 per group). Each main group were subdivided (according to the bleaching agent used) into four subgroups 10 teeth each; as following : control (un bleached) group, hydrogen peroxide group (Hp) 35%, carbamide peroxide group (CP) 37% group and sodium perborate (SP) group . The bleaching process was applied three times (4 days intervals) sequentially and the bleached teeth were stored in artificial saliva four weeks before bonding. Orthodontic brackets were bonded with a light cure composite resin and cured with LED light. After passing 24 hours of bonding procedure, the brackets were debonded by a Tinius-Olsen universal testing machine, to measure the shear bond strength. After debonding, each bracket base and the corresponding tooth surface were examined using a stereomicroscope and their Adhesive Remnant Index (ARI) was recorded. Results: The ANOVA test showed that the SBS of stainless brackets was significantly reduced by intracorornal bleaching agents. Furthermore, LSD showed no significant difference in SBS between the three types of bleaching agents used in stainless steel group. Whilst for sapphire group, the results The ANOVA test showed no significant difference in SBS between the bleached groups and the control group. Chi-square comparison no significant difference in failure site between bleached and control groups in both brackets types used. Conclusion: The effect of intracoronal bleaching on SBS was reduced SBS of stainless steel and not for sapphire. However, the intracoronal bleaching had no effect on the failure site of orthodontic brackets used.
The art of Islamic ceramics is considered one of the main pillars of the art of ceramics in the plastic arts, as his knowledge of what is presented in the Islamic arts intertwined in a special way. And the Islamic ceramics are indications of fertility and the rekindling of religious ties, controversy over them, and interpretation as additions to their vocabulary. Studies in the plastic arts began to empty the knowledge towards this direction, especially its relationship to the Arabic calligraphy and specifically the Islamic decoration, which derived the first aesthetic values from calling the artist Muslim pottery and potters to inviting the Arabic letter and Islamic decoration to indicate within the theory of "displacement" the aestheti
... Show More
Investment Bases directly and closely to an environment characterized by political, social and economic stability, and through a range of policies and institutions and economic laws that affect investor confidence and convince him directing investments to country without the other, where inter conditions and circumstances affecting the trends of capital and settle in, and political situation of the country and what is characterized of stability or disorder as well as economic conditions that are affected by what is distinguishes the country from geographic and demographic characteristics are reflected on availability of production elements and country's infrastructure.
... Show More
(1)
Thethesis of theresearch is to deal with relations between Russia and Yemen after 2011.That relationwas significant in different fields, historic, economic, strategic and cultural ones. There are mutual interestsbetweenRussia and Yemen, especially with the economic development and growth in Russia as an important partner to Yemen.Their has to an a great deal of progress in different types of relations, where as they were only partner in military relations. The studywasclassifiedintoto three sections: the first section dealt with strategic importance of Yemen to Russia. And second section dealt withthe military factor between Russia and Yemen. While the third section dealt with the economic factor between Russia and Yemen. In addi
... Show More
Background: Zinc is involved in a variety of
metabolic processes and it has a well known
antioxidant activity, so the measurement of its serum
level can have a special value in several diseases.
Objectives: The study is designed to determine the
serum zinc level in heart failure patients and to
compare it with that of healthy individuals and to
study the significance of the results obtained.
Methods: Atomic absorption spectrometer
technique was used to determine serum zinc level in
fifty heart failure patients and fifty healthy individuals
who were age and sex matched.
Results: The mean serum zinc level in healthy
individuals was about 45.5% greater than that of heart
failure patients. This diffe
The aim of this research is to find out why some matrix verbs are no longer complemented by the two types of infinitive clauses as it is the case in Elizabethan English . At that time (when Shakespeare was writing ), the same matrix verb triggers the two types of infinitive clauses as its complex transitive complementation .Such free variation is not possible in Present –Day English . In this corpus – based study , it is shown that the choice of the form of the infinitive clause is not free; there are certain syntactic ,sem- antic constraints that dete, - infinitive.
Numerical and linguistic methods were varied in interpretation unless they were in accordance with the grammar
Texts of speech, and this was one of the methods used by linguists and linguists as well
What they call them (the opposite is the opposite), and this is what the word "pregnancy"
Is a synonym for the term "interpretation." This term was often used for syntax
The physical and linguistic cause when an act exceeds the character in which it is known to be infringed, or when
The use of a tool with a little use of it, especially by scientists who knew about it
Pay attention to grammatical errors. The Arabs may have uttered the word and wanted to denounce it
He went even further when the eraser carried away his abr
Studies were conducted from 1980 to 1989 to determine the insect pests infested animal museum collections in Iraq. Twelve species of Coleoptera were recovered, eleven belonged to the Dermestidae, and one to the Tenebrionidae. Of these Anthrenus coloratus Reitt. and Phradonoma nobile (Reitt.) were the most commonest and widely distributed species. Trogoderma bactrianum Zhant. and Orphilus niger (Rossi) were recorded here for the first time in Iraq.
The research presents a case study of collecting materials and raw materials in a visual space that allows them to form a perception and meanings that inform the recipient by reconstructing them and inserting them into the surface of the artistic work and in such a way that the aesthetic act consists of a variety of media, touches and surfaces. The overlap of races within an environment characterized by unity. That is why the researcher in chapter one presented the problem of research, and the focus was on studying the multiplicity of materials and their aesthetic and functional role in the structure of creative work. The aim of the research is enhanced to identify the aesthetic performance function of the multiplicity of ores in the col
... Show More