ABSTRACT Background: Color changes that are detectable to human eye can affect the esthetic appearance of ceramic veneers. The purpose of this study was to evaluate and compare the effect of artificial accelerated aging on the color of ceramic veneers cemented with different resin cements. Materials and Methods: Sixty discs were prepared with 0.5 mm thickness, 30 discs made from IPS e.max press (Ivoclar Vivadent) and 30 discs were made from VITA Enamic (VITA Zahnfabrik). The discs were cemented with three resin cements: Variolink Veneer MV 0 shade (Ivoclar Vivadent), Rely X veneer Translucent shade (3M ESPE) and NX3 Nexus Clear shade (Kerr Corporation) with 0.1 mm thickness. The spectrophotometer Easyshade Advance was used to measure the color parameters (Lightness, axis a* of chroma and axis b*of chroma) immediately after cementation, after 150 and 300 hours of aging. The specimens were subjected to artificial accelerated aging in Accelerated Weathering Tester. Color change greater than 3.3 was considered unacceptable. One-way ANOVA, paired t-tests and Bonferroni adjusted t-test were used for statistical analysis (p <0.05). Results: Artificial aging caused high significant color change in both ceramic types, but there were non-significant difference in color change among the three resin cements used. The color change was between1.997-14.8 after 150 hours and it was between 2.179-15.68 after 300 hours. The color change of e.max discs after aging were within acceptable limit<3.3 whereas Vita Enamic specimens had shown unacceptable color change >3.3 after aging. Conclusions: The majority of color change after aging related to veneering materials while resin cement have only slight effect on color change after aging. IPS e.max had shown an acceptable color change after aging, so it is suitable for fabrication of restorations in esthetic zone while Vita Enamic should not be used in esthetic zone since it has poor color stability according to the results of this study.
The study aimed at recognizing the availability of the cultural intelligence dimensions in social studies book at the high school in the kingdom of Saudi Arabia (curricula system- joint program). The study used the descriptive approach and content analysis method. As tools of the study, the study adopted a list of cultural list of indicators and dimensions that suits the secondary stage social curricula. It further adopted a content analysis form designed to analyze the social studies book in the secondary school in the kingdom of Saudi Arabia. The study has reached several results, the most significant results were: There is a difference in including the cultural intelligence dimensions in social studies book at high school in the kingd
... Show MoreThis research aims to determine the role of employee performance evaluation of the achievement of the quality of human resources in the Office of the Inspector General / Martyrs Foundation requirements by employing comparison steps reference with the Office of the Inspector General / Ministry of Higher Education and Scientific Research, has been touching the researchers need the Office of the Inspector General / Martyrs Foundation to apply assess the performance is good for workers and the employment of its outputs to achieve the requirements of the above-mentioned system, and in order to stand on this role we raised the following question President: (is the quality of human resources requirements are achieved through the employm
... Show MoreIn this work, the spirurid nematode Hartertia gallinarum was reported in the intestine of the spotted sandgrouse, Pterocles senegallus, collected in three different locations: Ga'ara Depression, Iraqi Western Desert, Zurbatiyah and Al-Attariyah, Middle of Iraq. Description and measurements of the nematode were given. The role of termites in the infection of P. senegallus with H. gallinarum was discussed. Occurrence of H. gallinarum in P. senegallus represents a new host record.
Sn(II) complex of the type, [Sn(SMZ)2]Cl2 was synthesized by the interaction of Sulfamethoxazole ligand and Tin Chloride, the complex was confirmed on the basis of results of elemental analyses, FT-IR, UV-Vis, molar conductance (Ëm). The elemental analysis data, suggests the stoichiometry to be 1:2 (metal: ligand) and determination of the formula of a coordination a complex formed between the Sn(II) ion and the SMZ using Job’s method of continuous variations. The study of (Ëm), indicated the electrolytic nature type 1:2. The [Sn(SMZ)2]Cl2 was screened for antibacterial activity against Gram-ve (Escherichia coli and Gram+ve (Staphylococcus aureus) and (Candida albicans) antifungal. The IR spectral data suggested that the coordination sit
... Show MoreOne of the globalization results is (VAT) , so it is important to consider its results and impact on the tax system.
The Iraqi economy having wittnisd an acute transition period , still in need for a better care in aim to back it, especialy from the tax system.
The research is concerned with the (VAT) and its details –And for five chapters all the problomes connect are displayed .But yet the new system does not comply with the modern development and this is one of the defects of (VAT) in Iraq.
The history of (VAT)was also studied mentiorned and studied.
As a conclusion (VAT) is one of the m
... Show MoreThe research aimed to identify the level of reality of administrative values of sports activities in the Faculties of the university of Baghdad from the point of view of the leaders and those related to the divisions and units of student's activities and the case study method was adopted from the descriptive approach.