ABSTRACT Purpose: the aim of this in vitro study was to compare the marginal gap and internal fitness between single crowns and the crowns within three-unit bridges of zirconium fabricated by CAD-CAM system. Materials and methods: A standard model from ivoclar company was used as a pattern to simulate three-units bridge (upper first molar and upper first premolar) as abutments used to fabricate stone models, eight single crowns for premolar and eight of three units bridges. Crowns and bridges fabricated by CAD-CAM system were cemented on their respective stone models then sectioned at the mid-point buccolingaully and misiodistaly and examined under stereomicroscope. Result: the marginal gap in premolar crowns and premolar within bridge were within the acceptable value 120µm, one –way ANOVA showed that there was significant differences in the internal gaps among the areas. Independent t- Test showed there was significant differences between the premolar crowns and premolar crowns within bridges in marginal opening and cusp tip (lingually and distally) Conclusion: the marginal and internal gaps were in the bridge higher than those in the crowns. The areas of sloped surfaces such as chamfer area, occlusal area and cusp tip had high gap values in comparison with areas of flat surfaces such as axial wall and when the surface area of abutment increased, the marginal and internal gaps of abutment was increase.
The debate on the methodology of media and communication research is no longer subject to the logic of the contradiction between the quantitative and the qualitative approach, nor the logic of the comparison between them. The nature of the topics presented for research, the problems they raise, the goals to be achieved from the research, and the epistemological positioning of researchers are among the critical factors that dictate the appropriate approach or methodological approaches to conduct their research. This positioning means the implicit philosophical principles upon which any researcher relies and which determine the path he/ she takes to produce scientifically approved knowledge. The method of the researcher's access to the phe
... Show MoreThe sale of facial features is a new modern contractual development that resulted from the fast transformations in technology, leading to legal, and ethical obligations. As the need rises for human faces to be used in robots, especially in relation to industries that necessitate direct human interaction, like hospitality and retail, the potential of Artificial Intelligence (AI) generated hyper realistic facial images poses legal and cybersecurity challenges. This paper examines the legal terrain that has developed in the sale of real and AI generated human facial features, and specifically the risks of identity fraud, data misuse and privacy violations. Deep learning (DL) algorithms are analyzed for their ability to detect AI genera
... Show MoreThe research aims to identify the availability of some basic competencies that are required to be available to workers in digital agricultural Extension from the point of view of senior management, middle management, and, employees with Post-graduate education degrees, represented by the following: Transition to digital agricultural Extension for sustainable and smart family farms, benefiting from international expertise and experiences in applying for Digital agricultural Extension, preparing and implementing Extension messages through platforms, factors affecting the effectiveness of digital agricultural Extension and its platforms, following up and evaluating the activities and programs of the digital Extension platform. The research pop
... Show MoreThe performance of a synergistic combination of electrocoagulation (EC) and electro-oxidation (EO) for oilfield wastewater treatment has been studied. The effect of operative variables such as current density, pH, and electrolyte concentration on the reduction of chemical oxygen demand (COD) was studied and optimized based on Response Surface Methodology (RSM). The results showed that the current density had the highest impact on the COD removal with a contribution of 64.07% while pH, NaCl addition and other interactions affects account for only 34.67%. The optimized operating parameters were a current density of 26.77 mA/cm2 and a pH of 7.6 with no addition of NaCl which results in a COD removal efficiency of 93.43% and a specific energy c
... Show MoreBackground: The Andrews’ six keys of normal occlusion contribute individually and collectively to the total scheme of occlusion and, therefore, are viewed as essential to successful orthodontic treatment. The present research aims to evaluate the presence of the parameters of the Andrews’ Six Keys of normal occlusion in a sample of 100 Iraqi adults with complete permanent dentition and clinically acceptable normal occlusion (Angle’s Class I) in Baghdad city. Their age range 18-25 years (60 males and 40 females). Materials and methods: Each patient was subjected to clinical examination and then study cast models were made, with their occlusal records. The measuring tools that have been used involved: Three-dimensional goniometer to me
... Show MoreMany waste materials can be repurposed effectively within asphalt concrete to enhance the performance and sustainability of pavement. One of these waste materials is sawdust ash (SDA). This study explores the beneficial use of SDA as a substitute for limestone dust (LD) mineral filler in asphalt concrete. The replacement rate was 0%, 15%, 30%, 45%, and 60% by weight of total mineral filler. Scanning electron microscopy (SEM) was employed to assess the surface morphology of Sawdust (SD), SDA, and LD. In addition, a series of tests, including Marshall stability and flow, indirect tensile strength,moisture susceptibility, and repeated uniaxial loading tests, were conducted to examine the performance characteristics of asphalt mixtures of diffe
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In this research we built a mathematical model of the transportation problem for data of General Company for Grain Under the environment of variable demand ,and situations of incapableness to determining the supply required quantities as a result of economic and commercial reasons, also restrict flow of grain amounts was specified to a known level by the decision makers to ensure that the stock of reserves for emergency situations that face the company from decrease, or non-arrival of the amount of grain to silos , also it took the capabilities of the tanker into consideration and the grain have been restricted to avoid shortages and lack of processing capability, Function has been adopted
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