ABSTRACT Background: One of the major problems of all ceramic restorations is their probable fracture against the occlusal forces. The objective of this in vitro study was to evaluate the effect of two gingival finishing lines (90°shoulder and deep chamfer) on the fracture resistance of full contour CAD/CAM and heat press all-ceramic crowns. Materials and Methods: Thirty two maxillary first premolars were prepared to receive full contour CAD/CAM (zolid) and heat press (Cergo Kiss) ceramic crowns using a special paralleling device (Parallel-A-Prep). The teeth were divided into four groups according to the type of finishing line prepared. Each crown was cemented to its corresponding tooth using self-etch, self-adhesive dual cure resin cement. Following storage for 1 week in distilled water at room temperature, teeth were subjected to thermal cycling. Fracture resistance was determined using a universal testing machine, and the samples were investigated microscopically from the point of view of the origin of the failure. Statistical analysis was carried out using the one-way ANOVA and Student’s t-tests. Results: The mean values of fracture resistance for CAD/CAM group showed 1367.250+178.967 N for 90°shoulder margins and 1109.250+252.455 N for the deep chamfer margins. ANOVA test results revealed high significance between and within the groups. The mean values of fracture resistance for heat press group were 548.562+272.471 N for 90°shoulder margins and 247.912+96.995 N for the deep chamfer margins expressing statistical significance. Conclusions: The results of this study pointed to a relationship between the design of the cervical finishing line and the fracture strength of the full CAD/CAM crowns and the full heat press ceramic crowns. Both 90° shoulder and deep chamfer finishing lines are suitable for zolid crowns while the 90° shoulder is more suitable for the Cergo Kiss crowns than the deep chamfer preparation. Key words: Full contour, All-ceramic crowns, CAD/CAM, Heat press, Fracture strength.
Successive waves and generations of terrorists attacked the Iraqis in the years following the fall of the regime in Iraq in 2003, after the US invasion of the country under the pretext of weapons of mass destruction. Hence, the Iraqi people enrolled in ongoing war with these armed groups which led to massive casualties due to blasts and missile injuries.
Mechanism of blasts injury can be classified into primary, secondary, tertiary, and quaternary. While bullet injuries can be classified into low and high-energy injuries, the type and severity of the injury will influence the type of management, together with facilities available in
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The antibacterial effect of (Eruca sativa) extract was evaluated by an in vitro study testing the growth of various Gram-Positive and Gram-Negative bacteria . The bactericidal activity of this extract was analyzed by serial dilution in tubes. This study,found that Gram-Negative and Gram-Positive bacteria susceptible to very low eruca concentrations. On the other hand, Gram-positive bacteria were more susceptible than Gram-negative bacteria, the minimal bactericidal concentration of Gram-positive bacteria was 5 mg ml-1 but minimal bactericidal concentration of Gram-negative bacteria was 10 mg ml-1 that mean duble inhibation concentration of Gram-positive bacteria . this study suggest that Eruca sativa leaves have inhibation effect on Gra
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This research delves into the role of satirical television programs in shaping the image of Iraqi politicians. The research problem is summarized in the main question: How does satire featured in television programs influence the portrayal of Iraqi politicians? This research adopts a descriptive approach and employs a survey methodology. The primary data collection tool is a questionnaire, complemented by observation and measurement techniques. The study draws upon the framework of cultural cultivation theory as a guiding theoretical foundation. A total of 430 questionnaires were disseminated among respondents who regularly watch satirical programs, selected through a multi-stage random sampling procedure.
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In the current research, we investigated the absorption spectrum for R590 and C480 dyes in ethanol solvent for different dye solution concentrations of 10-4, 10-5 and 10-6M. These dyes have been prepared and studied before and after gamma irradiation (first, second ionization) using cesium-137 source with absorbed doses of 18.36 Gy (time exposure of 10 days) and 73.44 Gy (with time exposure of 40 days). We noticed that the absorption intensity was decreased with decreasing concentration, before gamma irradiation while the absorption spectrum peak shifted towards the short wavelength (blue shift). It was also found that the intensity of absorption spectrum increased and shifted the absorption spectrum peak towards the long wavelength (red
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This paper details the process of designing, analysing, manufacturing, and testing an integrated solid-state hydrogen storage system. Analysis is performed to optimise flow distribution and pressure drop through the channels, and experimental investigations compare the effects of profile shape on the overall power output from the fuel cell. The storing of hydrogen is given much attention in the selection of a storage medium, and the effect of a cooling system to reduce the recharging time of the hydrogen storage vessel. The PTFE seal performed excellently, holding pressure over 60 bar, despite requiring changing each time the cell is opened. The assembly of the vessel was simple and straightforward, and there was no indication of pressure
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A collection of pictures of traditional Kurdish women's national clothing and contemporary clothing was collected. A visit was also made to the city of Sulaymaniyah and the city of Halabja to find out the foundations of traditional clothing for the Kurdish regions and the impact of contemporary fashion on traditional dress. Which represents the culture and regionalism and reflects the picturesque nature of northern Iraq, and in order to complete the study, the parametric measurements of the clothes were analyzed and the graphs of the dress and its accessories were re-drawn to understand and make a comparison between them to study the clear influences and changes and examine the possibility of benefiting from them in sewing contemporary f
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The aim of the research is to identify the educational and psychological effects of the positive and negative aspects of using social networking websites. The researcher administered a number of questions to (250) users of different types of social networking websites. He analyzed his research results and obtained a number of results. The research has reached a number of recommendations and suggestion: Regulating the use of social media. Monitoring the parents of the sites used by children in a way that they do not feel they are observers. It is necessary to devote an hour daily to show the importance of real social life for children other than using social media. It is necessary to show the importance of choosing friends who hav
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