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.
This research main goal is to identify the concept of relating and eliminating in visual arts and how does work as a philosophic and aesthetic concept of great importance in visual arts, specially in abstract field, for it is related to ornament (geometrical or botanical) for its rising is a sign for the operations of adding and deleting, and studying art products with such trend in their configuration and the boundaries of utilizing this concept. Then taking the art works of the artist Mahdi Mutashar as a research sample for procedural analysis. And outputs that tend in this direction in it's formal being and know the limits of the concept of work -related dialectically interconnected. And then deal procedurally with the works of Iraqi
... Show MoreThe current research presents a study of the sculptural body in the space of the theatrical show through reviewing most of the ideas, propositions and workings presented by philosophers and directors within the space of the show, that there were various experiences of employing those spatial formations through the mediator (the space) based on sculpturing the body in achieving those formations, which contributed in building a symbolic picture of various structural connotations. That was formulated through the research chapters, which include the first chapter (the methodological framework) which consists of two sections. The first section (the duality of space formation and imaginations). The second section (sculptural body sequences in
... Show MoreMany reasons combined behind the Standing of U.S. against Britain in its aggression against Egypt in 1956; the consensus of world opinion on the need to stop the aggression and the fear of the Soviet military intervention which mean a new world war.
United States desired to weaken British influences in the region in general to get new oil gains in the Arabian Gulf and Egypt at the expense of Britain. The exiting of Britain from the area served U.S. strategic interests in the Middle East in general and Egypt in particular to keep the flow of oil for U.S advantage.
The United States wanted to keep its image in the region to apply its future political projects including Eisenhower Project, which intended to take the position of Britis
Abstract
Abstract has many advantages as has historically been one of the regions leading cultural centers . for centuries , it has been a center of commertial and financial operations in Iraq. it is also rich in archeological sites and natural resources, but because of its wars and implementation of urban development strategies are effective and sustainable , so contracted the secretariat of Baghdad with the company (khatib and scirntiffic) for the preparation of the comprehensive development plan for the city of Baghdad in 2030 and funded by the world bank and the fact that the plan was approved ( three stages of it ) and only one phase remains the fourth stage, which is under discussion the aim of the
... Show MoreBackground: five clinical phases were described in patients with chronic (HBV) infection: HBeAg- positive HBV infection, HBeAg- positive chronic HB, HBeAg negative HBV infection, HBeAg-negative CHB and occult HBV infection. Aim: This study aimed to determine the incidence of the unclassified phase (gray zone) in chronic hepatitis B patients and its significant in the clinical practice. Patients and methods: The study was conducted retrospectively on 109 patients' who have HBsAg positive for more than 6 months. The data recorded include; HbeAg and anti-HBe Ab, ultrasound of the abdomen, HBV DNA load and alanine aminotransferase (ALT), accordingly; we classify the patients to known clinical phases. Patients who were unfit one of these phases
... Show MoreThe research aims to Measuring the auditors' commitment with the analytical procedures of the economic units of the research sample in carrying out their professional duties and the importance of this commitment to the tax administration and the extent of their reliance on the external auditor's report and the financial statements in determining the income tax and its effect on the tax revenues.
The research depends on a main hypothesis stating that "The use of analytical procedures by the external auditor has a positive impact on the availability of confidence and credibility in the financial statements presented to the tax administration and has a positive impact on the tax revenues."
The resear
... Show MoreThe research aimed to explore the recall habits and developing the right recall habits at middle school students. A sample of (40) students were chosen intentionally from middle school students in two schools (almntzr- zany aleabdyn) with an average of (20) students from each school. They were evenly distributed in two experimental and control groups. To achieve the aims of the research, a scale was designed to measure the recall habits, and a preparation of an educational program to develop recall habits.
To process data statistically, the researcher used several statistical methods such as Pearson correlation coefficient, chi-square, T-test for one sample, T-test for two independent samples, Wilcoxon test, Mann-Whitney test, ET
... Show MoreRecent technological developments in the mass media a major paradigm shift in important segments of society, particularly among young people in particular social networking sites including (Facebook) .
it was able to link the sprawling parts of the world and paved the way for all the communities of convergence and exchange views, ideas and desires as provided by their ability to communicate through the use of video clips,pictures,share files, chat, communicate and direct interaction between the audience for this the means. Wondered problem Find the role that can be played using the university youth to the social networking site (Facebook ) to modify their attitudes or their interest in Iraqi society issues, With focused research objec
The main purpose of the research is to diagnose the importance of the role that strategic memory plays with its three variables (content, structure, and processes) in helping the human resource department to use the COSO model with its five components (culture and governance, strategy and objectives, performance, communications and information, and feedback) in auditing activities and tasks Her own. As the research problem emphasized the existence of a lack of cognitive perception, of the importance of strategic memory, and the investment of its components in the rationalization of the application of the COSO model. and therefore it can be emphasized that the importance of the research is to provide treatments for problems relate
... Show MoreThis work has been carried out to develop national drug product contains 2.5mg/ml clonazepam as oral drop; it is used for the treatment of epilepsy in infants and children.
Several formulations were prepared using oral drop base, flavor, buffer, sweeteners and preservatives. Selection of best formula relied solely on physic-chemical testing of samples.
Stability study was conducted on the product for six months at different temperatures to determine the expiration date and the best storage conditions.
From the study we obtained an oral drop of good clear solution. The expiry date calculated to be not less than 2 years.