Background: The success and maintenance of indirect dental restorations is closely related to the marginal accuracy, which is affected by many factors like preparation design, using of different fabrication techniques, and the time of taking final impression and pouring it. The purpose of this in vitro study was to evaluate the effect of different pouring time of conventional impression on the vertical marginal gap of full contour zirconia crowns in comparison with digital impression technique. Materials and Methods: Forty sound recently extracted human permanent maxillary first premolar teeth of comparable size and shape were collected. Standardized preparation of all teeth samples were carried out to receive full contour zirconia crown restoration with deep chamfer finishing line all around the tooth with (1mm) depth, axial length (4mm) and convergence angle (6 degree). The specimens separated into two groups; Group A; eight specimens were scanned digitally by using Omnicam scanner; Group B; conventional impressions were taken for the remaining thirty two specimens and further subdivided to four groups according to the time of impression pouring; Group B1: PVS were poured after 30 minutes; Group B2: PVS were poured after 24 hours; Group B3: PVS were poured after 7 days; Group B4:PVS were poured after 14 days. Marginal discrepancy was measured at four points at each tooth surface. Sixteen points per tooth were measured using digital microscope at (180X) magnification. One-way ANOVA test and LSD test were carried out to see if there was any significant difference among the means of the conventional impression groups. Independent samples t-test was carried out to examine if there is any significant difference between digital and conventional impression technique. Results: group B2 had the least mean of marginal gap with statistically significant difference when compared to group B1 and statistically highly significant difference when compared to group B3 and B4. There was a statistically highly significant difference in the vertical marginal gap between digital impression technique and conventional impression. Conclusions: the pouring of conventional impression after 24 hours provides better marginal fit than other pouring time. The digital impression provides better marginal fit than conventional impression.
Iraq is one of the most important countries in the world that has received its share of terrorist acts by the terrorist organization the Islamic State of Iraq and al-Sham (ISIS), which has caused instability, especially during the period of ISIS's control of seven Iraqi provinces (2014-2017). This stage has caused a decline in the levels of human and economic development and its inconsistency with the capabilities and needs of the Iraqi population. Therefore, this study aims to investigate the hypothesis that there is a close relationship between the decline in development in Iraq and the brutal practices of ISIS that it committed during his period of control over many Iraqi cities and regions. This study used several method
... Show MoreThis paper displays a survey about the laboratory routine core analysis study on ten sandstone core samples taken from Zubair Reservoir/West Quarna Oil Field. The Petrophysical properties of rock as porosity, permeability, grain's size, roundness and sorting, type of mineral and volumes of shales inside the samples were tested by many apparatus in the Petroleum Technology Department/ University of Technology such as OFITE BLP-530 Gas Porosimeter, PERG-200TM Gas Permeameter and liquid Permeameter, GeoSpec2 apparatus (NMR method), Scanning Electron Microscopy (SEM) and OFITE Spectral Gamma Ray Logger apparatus. By comparing all the results of porosity and permeability measured by these instruments, it is clear a significant vari
... Show MoreThis study aims to identify the level of students’ awareness at Imam Muhammad bin Saud University of the requirements of married life in the light of social changes and suggested methods to deepen this awareness (according to the Islamic educational vision) from their own perspective. In this study, the researcher used the descriptive approach with a survey research method, depending on questionnaires to collect data, which he applied to students of College of Sharia in Imam Muhammad bin Saud Islamic University, as well as, students in the fields of Sociology, Social Work, and Psychology in the College of Social Sciences. The findings of the study revealed that students are aware of the requirements of married life concerning mutual ri
... Show MoreAlthough renewable energy systems have become an interesting global issue, it is not continuous either daily or seasonally. Latent heat energy storage (LHES) is one of the suitable solutions for this problem. LHES becomes a basic element in renewable energy systems. LHES compensate for the energy lack when these systems are at low production conditions. The present work considered a shell and tube LHES for numerical investigation of the tube rotation influence on the melting process. The simulation and calculations were carried out using ANSYS Fluent software. Paraffin wax represents the phase change material (PCM) in this work, while water was selected to be the heat transfer fluid (HTF). The calculations were carried o
... Show MoreWheat is rich in sources of fiber, oligosaccharides, and resistant starch, simple carbohydrates which may have a protective role against carcinoma. Additionally, Whole wheat/bran as well includes contains phytochemicals such as flavonoids, lignans, folate, phytosterols, phenolic acids, and tocols. The above phytochemicals suitable forms antioxidant and cholesterol-reducing activities. Phytoestrogens are regarded as especially essential in the preventative measures of hormonally dependent malignancies such as breast cancer (BC). In this study lowered BC risk has been associated with whole grain/bran consumption with an odds ratio (OR=0.24 and 95 %CI=0.10-0.56). Wheat/bran appears to have a reliable protective impact against BC. While intake
... Show MoreFive serological methods for detection of Brucella were compaired in this study, Four of the methods are commonely used in the detections:- 1-Rose-Bengal: as primary screening test which depends on detecting antibodies in the blood serum. 2-IFAT: which detects IgG and IgM antibodies in the serum. 3-ELISA test: which detects IgG antibodies in the serum. 4-2ME test: which detects IgG antibodies The fifth methods. It was developed by a reasercher in one of the health centers in Baghdad. It was given the name of spot Immune Assay (SIA). Results declares that among (100) samples of patients blood, 76, 49, 49, 37, and 28. samples were positive to Rose Bengal, ELISA, SIA, 2ME and IFAT tests, respectively. When efficiency, sensitivity and specific
... Show MoreThis study was conducted at the Poultry Research Station in Abu Ghraib, Department of Agricultural Research, Ministry of Agriculture, the experimental field during three months (Three terms for a period of four weeks), from 10 th of December 2019 to the 10 th of January 2020. The study aimed to determine the effect of using different proportions of chlorella algae in layer hen ration and its effect on the hen's productive performance and numbers of lactobacilli bacteria in the intestine. The experiment included 400 laying hens (ISA Brown) of 54 week old which were fed according to the standard requirements mentioned in the guide for this breed (ISA Brown layer management guide). The hens raised using a 3 stage cages system with five hens in
... Show MoreWellbore stability is considered as one of the most challenges during drilling wells due to the
reactivity of shale with drilling fluids. During drilling wells in North Rumaila, Tanuma shale is
represented as one of the most abnormal formations. Sloughing, caving, and cementing problems
as a result of the drilling fluid interaction with the formation are considered as the most important
problem during drilling wells. In this study, an attempt to solve this problem was done, by
improving the shale stability by adding additives to the drilling fluid. Water-based mud (WBM)
and polymer mud were used with different additives. Three concentrations 0.5, 1, 5 and 10 wt. %
for five types of additives (CaCl2, NaCl, Na2S
The interest of many companies has become dealing with the tools and methods that reduce the costs as one of the most important factors of successful companies, and became the subject of the attention of many economic units because of the impact on the profits of company, and since the nineties of the last century the researchers and writers gave great attention to this subject, especially in light of the large competition and rapid developments in cost management techniques, as well as the wide and significant change in production methods that have been directed towards achieving customer satisfaction, all this and more driven by economic units in all sectors whether it is service or productivity to find methods that would reduc
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