Background: This in vitro study was carried out to evaluate the effects of various veneering dentin ceramic thicknesses and repeated firings on the color of lithium disilicate glass-ceramic (IPS e.max Press) and zirconium-oxide (IPS ZirCAD) all-ceramic systems, measured by clinical spectrophotometers (Easyshade Advance 4.0) . Materials and methods: The 72specimens cube-shaped have the dimension of about 11 mm in width, 14 mm in length, 1mm in thickness, these cores divided into 3 groups according to the type of material each group have (24)core specimens. Each group had been divided into three sub-groups (each having 8 specimens) according to veneering with dentin ceramic thicknesses: as 0.5, 1, or 2 mm (n=8). IPS e.max press and ZirCAD cores group had been veneered with IPS e.max Ceram dentin ceramic shade A2 according to manufacturer’s instructions and the metal group had been veneered with IPS classic dentine ceramic with shade A2 according to manufacturer’s instructions. Repeat firings (3, 5 and 7 times) had been applied on all the specimens. Color differences among ceramic specimens had been measured using a clinical spectrophotometer (VITA Easyshade); the color data had been expressed according the Vita Classic shade guide. Results: The shade of all specimens had been compared inside the subgroups and with the main groups. The percentage of color agreement among the subgroups showed the color of all ceramic systems had been affecting by firing interval, the ceramic thickness and brand of ceramic. The number firings intervals applied on the all ceramic system has a significant effect on the final color, the increase of firing number change the color to a darker and reddish color. The 5th firing interval is the point at which the major color changes happened (darker shade), and in next interval (7th firing) less color changes happened. The thickness of veneering ceramic affected the color significantly. The 0.5 mm specimens in all groups showed the highest percentage of agreement (less color changes) after firing intervals, then the 1mm came and the least percentage of agreement ( highest color changes ) was the 2 mm specimens. The Brand of veneering ceramic and the type of core record a significance difference in color changes when exposed to firing heat. Conclusion: With limit of this study, the final color of the all ceramic system definitely affected by the number of firing cycle exposed to, and the veneering ceramic thickness have a clear effect on the final shade of the all ceramic tested.
The current research aims to identify the stressful life events among middle school students in terms of gender (male-female), academic branch (scientific-literary), and the Life Skills of the students of the preparatory stage in terms of gender (male-female), and academic branch (scientific-literary). Additionally, the study aims to identify the relationship between stressful life events and life skills in middle school students. A sample of (200) students who were selected randomly from the Directorate of education of Baghdad Karkh/ III was used in this study. To achieve the objectives of the current research, the researcher has adopted two scales, the stressful life events scale for the researcher Al-Sultan (2008), and the life skills
... Show MoreA field Experiment was carried out in Baghdad for the purpose of compare five horticulture machines during used two types of fuel deffirance in octane number, normal and super fuel which produced in Iraqi and measuring the vibrations transmitted of the three axes are longitudinal X , lateral Y and vertical Z from handlebar in (Mowers) to the operator which walks behind the mower, and the determine of the productivity practical of cutting, productivity passing and fuel consumption. Experiment Factorial used with two factors, The first factor was Five Mowers vary in width , types, weight and company manufacturer, The Second factor was the types of fuel used internal combination engine horticulture mowers were Normal fuel with Octane Number 82
... Show MoreSongs are considered as an educational and a substantial dependable references used in teaching and learning, particularly the so - called foreign language learning that allows learners to adapt to the target language culture and to develop their language learning skills including: listening comprehension, reading comprehension, speaking and writing. Consequently, it can be said that the Francophone songs with the musical richness and resonance specifically facilities French language learning skills for all levels of education and achieve short and long terms predetermined educational language learning goals.
In fact, language learning through songs method does not only include the
... Show MorePoly (3-hydroxybutyrate) (PHB) is a typical microbial bio-polyester reserve material; known as “green plastics”, which produced under controlled conditions as intracellular products of the secondary metabolism of diverse gram-negative/positive bacteria and various extremophiles archaea. Although PHB has properties allowing being very attractive, it is too expensive to compete with conventional and non-biodegradable plastics. Feasibility of this research to evaluate the suitability of using a watermelon-derived media as an alternative substrate for PHB synthesis under stress conditions was examined. Results, include the most nutrients extraction, indicated that the watermelon seeds contain a high content of nutrients makes them a promisi
... Show Morethe financial resources represent a basic factor of production ;It is obvious that the housing sector needs the resources to finance the building operation to produce all the housing units. Finance is the cornerstone of any housing strategy , as its successes dependent on the success of the financing methods and the creation of charnels and effective methods for the provision of the required finances for both individuals and instantly concerned with the production of housing units. The kinds of financial institutions vary from one country to another according to the nature of the economic and financial system. The lending conditions also vary as well as the capital cost of the housing units needed The housing operations is concer
... Show MoreThe tagged research is concerned with observation and investigating the concepts of consistency and harmony in contemporary Iraqi painting (selected models) in order to reveal the mechanisms and rules of these two concepts in the artistic field and their mechanisms of operation. How reflected tools Consistency and harmony in contemporary Iraqi painting? What is consistency and what are its mechanisms and principles? Is consistency a unit product quality? Are there similarities between consistency and harmony? What is harmony and its principles and rules? As for the second chapter, it included two topics that dealt with the first topic - consistency and harmony between concept and significance, while the second topic meant - histor
... Show MoreSoftware-defined networking (SDN) is an innovative network paradigm, offering substantial control of network operation through a network’s architecture. SDN is an ideal platform for implementing projects involving distributed applications, security solutions, and decentralized network administration in a multitenant data center environment due to its programmability. As its usage rapidly expands, network security threats are becoming more frequent, leading SDN security to be of significant concern. Machine-learning (ML) techniques for intrusion detection of DDoS attacks in SDN networks utilize standard datasets and fail to cover all classification aspects, resulting in under-coverage of attack diversity. This paper proposes a hybr
... Show MoreChronic renal failure (CRF) is progressive irreversible destruction of kidney tissue by disease which, if not treated by dialysis or transplant, will result in patient's death. This study was carried out on 30 patients (17 male and 13 female) with chronic renal failure. The aim of this research was studied the changes in the level of total protein ,albumin, calcium ,ionized calcium, phosphorous , iron ,ALP, LDH ,CK and FFA in patients with CRF before and after hemodialysis .The obtained results have been compared with 30 healthy subjects as control group (18male and 12 female). The results showed that there was significant increase in the level of calcium ,ionized calcium, phosphorous ,iron ,ALP,LDH,CK and FFA ,while there was a signifi
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