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.
Abstract
The scope of the humanitarian tragedies in the Arab region has widened after the conflicts that erupted over the past years, exacerbation to include educational, cultural, and social dimensions, economic and moral aspects of the displaced families, especially after the emergence of terrorist organizations and sectarian conflicts which overthrew human and led to various political and demographic changes, forcing citizens to leave their homes, fleeing with their families from the danger of murder, terrorism, and violation to other safer areas inside or outside their countries. Women and children were the vast majority of the displaced who were subjected to great pressures, The host communities bore the pro
... Show MoreThe study searches for the possibility of using duckweed Lemna spp. to reduce the concentration of heavy metals (zinc and iron) in the wastewater of Baghdad by culturing two different densities of the plant with a fresh weights 5 and 10 g/l and without the plant under optimum uncontrolled conditions. The result showed that there was a significant differences at the possibility level of (p? 0.05) for the three treatments, as the highest percentages for zinc removal in the second day for the plant treatment of 5 g/l were 66.40%, while the highest percentage of iron removal were in the tenth days for the plant treatment 10 g/l were 80 %, and noticed that the increase of the heavy metals concentrations accumulated in the plant after bei
... Show MoreObjectives: To assess the pediatric nurses' knowledge about the nosocomial infection owl), and to fud out the
relatiouships between their knowledge about the nosocomial infection and demographic data.
Methodology: A descriptive study was carried out at neonatal intensive care units OVICUs) of Baghdad
Pediatric Teaching Hospitals. It was started from the end of April to the end of October, 2008. A purposive
sample of (28) pediatric nurses were selected. The data were collected by self-administered questiormaire. The
validity of the questionnaire was detemined through a panel of experts, while its reliability was detemined
through the pilot study. The data were analyzed by descriptive and inferential statistics through th
She noted most of the results of research conducted on the use of computers and the Internet in the areas of administrative, economic, agricultural and educational to a significant improvement in learning outcomes of these groups in the development of mechanisms of action, has increased rates of computer use and applications in various spheres of life at very fast pace so that the computer and the Internet is a vital part of any activity, whether administrative or research or the media, hence it can be said that the use of computers and the Internet in the management of public relations activities in any organization can accelerate the pace of echo positive goals and purposes of public relations, this study comes to looking at us
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Due to the significance of hospital drinking water, a study was done to assess the water in three hospitals in Baghdad (Al-Yarmouk Teaching Hospital, Ibn Sina Hospital, and Ibn-Al-Nafis Hospital) for its nature and quality, compare it to other hospitals in terms of its physical, chemical, and bacterial specifications, and compare it to international standards. According to Iraqi standards from 2009 and WHO standards from 2011, Chemical factors were measured, which included pH, Total Dissolved Solids (TDS), and Calcium Ion (Ca+2). Reported readings are all within acceptable ranges for drinking water. In contrast, turbidity, total hardness (T.H.), chlorides (Cl-), magnesium (Mg+2), the number of aerobic plates (APC), total coliform (T
... Show MoreThe present study includs the isolation and identification of Keratinophilic fungi in fresh water samples collected from Tigris river in Baghdad, Iraq. Samples were collected from different districts of Baghdad (Al-Rustumia, Madina Al-Teb, Al-Azamia, Al-Kadimia, Al-Dorha and Al-Kanah). The water samples were examined for keratinophilic fungi by the plating method culturing and Hair Baiting Technique. A total number of 18 genera are recorded, in which the Tigris water indicates an impressive diversity of fungi. A variety of fungal strains were isolated from river water, out of 814 fungal colonies, Aspergillus terrus (5.5%) was the most frequent species, followed by Asperg
... Show MoreThe construction sector is considered an important and influential pivot in the national economy of any country. Nations are working to develop this sector, receiving modern and developed techniques. So, this sector can be a carrier or a receiver of modern technologies. The cost of technology transfer between the international companies that sponsor this sector is a matter of great importance, especially since different factors affect the need for this advanced technology. The cost of technology transfer in construction is related to multiple factors presented by Knowledge, equipment, plant, hardware and software. The lack of distinguishing and evaluating the direct and indirect costs in the construction sector during
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