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.
Leaching scheduling techniques are one of the suggested solutions for water scarcity problems .The aim of the study is to show the possibility of using leaching scheduling, when applying the irrigation scheduling program for a certain irrigation project, which was prepare by Water Resources Engineering –University of Baghdad with some modifications to generalized it and it make applicable to various climatic zone and different soil types.
The objectives of this research is to build a system that concerns the prediction of the leaching scheduling (depth and date of leaching water), illustrating the main problems (soil salinity, save the amount of leaching requirement, and to maintain crops growth).The other objective is to compare be
This study aims to identify how the Zakat Fund contributes to financing entrepreneurial projects; and the role that these projects play in achieving economic and social development, despite the importance that contracting projects have in most countries as the main engine of growth; however, they still face many challenges that In the forefront of which is the challenge of obtaining financing; in this regard, it is possible to resort to the use of Zakat funds in the Islamic economy as it is a funding source that is closely proportional to the characteristics and goals of entrepreneurial projects in achieving development;
 
... Show MoreThe Arab literature in Andalusia was distinguished by its special nature, in addition to the distinction of its influencing rhythm in our souls, it represents the natural extension of the Arab-Islamic civilization in Morocco, that civilization that collapsed with insecurity and stability and the exit of Muslim Arabs from those countries and the defeat of Muslims, their civilization has ceased, and only remains of them witnessing For its leaders in a safe and stable life, but literature in Andalusia underwent many experiences that express the lives of Arab Muslims there, especially what distinguished the Andalusian Muslims from their many battles and conquests, but they did not suffer as their support during the fall of Andalusia and the
... Show MoreWarm dark matter (WDM) models offer an attractive alternative to the current cold dark matter (CDM) cosmological model. We present a novel method to differentiate between WDM and CDM cosmologies, namely, using weak lensing; this provides a unique probe as it is sensitive to all of the “matter in the beam,” not just dark matter haloes and the galaxies that reside in them, but also the diffuse material between haloes. We compare the weak lensing maps of CDM clusters to those in a WDM model corresponding to a thermally produced 0.5 keV dark matter particle. Our analysis clearly shows that the weak lensing magnification, convergence, and shear distributions can be used to distinguish
The researcher concluded that it consists of several types of structures, where the intellectual structure related to the choice of the idea, its treatment, its effect, the choice of the topic, the way ideas are addressed and presented in the film, and then the dramatic structure of the film's characters, the formulation of its events, its dramatic composition, its temporal arrangement, the identification of the parties to the conflict and their management, then these are formulated. Visions and ideas through the visual and audio signal systems, which work to highlight the stylistic features in the character of the film director.
There is no doubt that the oud is one of the most important folk musical instruments in Iraq. It has been known since the ages of ancient Iraq in its form, strings, and the way to play it through the clay number. On them, however, they have participated in showing the instrument the greatest potential and musical aesthetics, and the interested person may be wondering about ways to learn to play this instrument, so the training methods varied between personal interpretations on the one hand and systematic teaching in educational institutions on the other hand, especially that they have received the attention of educational institutions Miya, that which must adopt an appropriate and scientific strategy that accompanies global education pro
... Show MoreMy research deals with the positions that the Prophet (PBUH) distressed. And condolences to those who lost her father and other problems and calamities that impede the life of women, has been given to the Lord of men, and good qualities, to strike the nation's finest proverbs in ensuring lost and lost of women and children, to be shown to us humanity in its finest form, and the best analyzed, and I hope God help And guidance and Rashad
The logistic regression model is one of the oldest and most common of the regression models, and it is known as one of the statistical methods used to describe and estimate the relationship between a dependent random variable and explanatory random variables. Several methods are used to estimate this model, including the bootstrap method, which is one of the estimation methods that depend on the principle of sampling with return, and is represented by a sample reshaping that includes (n) of the elements drawn by randomly returning from (N) from the original data, It is a computational method used to determine the measure of accuracy to estimate the statistics, and for this reason, this method was used to find more accurate estimates. The ma
... Show MoreThis study aims at identifying thinking, its aspects, controls, thinker’s characteristics, and the attempts that followed by Ibrahim’s people. This was achieved under Ibrahim’s story, (peace and blessing be upon him), in the Holy Qur’an. The study used the descriptive method through induction and deduction. The study reached the following results: thinking is an organized reasonable human action, which includes all human life in the fields of science, knowledge, and calling for Allah. It depends on remembering what is already in the memory and it should be subjected by revelation and Islamic legislation. The study illustrated that the most important thinking controls are monotheism, piety, Islamic legislation, the Holy Qur’an,
... Show MoreThe study aimed to identify the role of the teacher in confronting intellectual extremism in high school students, and identify the differences of statistical significance in the role of teacher in confronting intellectual extremism in secondary school students according to gender variable (males, females) and the duration of service (less than 5 years more than 5 years), the sample was consisted of (100) teachers with (50) male and (50) female in the city of Bayaa, Dora and Sadiya, the measure of intellectual extremism was applied by the researcher, and the study reached a role of the teacher in facing the intellectual extremism at Secondary school students, and the existence of differences of statistical significance in the role
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