Background: The displacement of artificial teeth during complete denture construction presents major processing errors in the occlusal vertical dimension which were verified at the previous trial denture stage. The aim of this study was to assess the effect of delay in processing after final flask closure and tension application on the vertical acrylic and porcelain teeth displacement of complete dentures constructed from heat cured acrylic and the results were compared with the conventional processing method. Materials and methods: forty samples of identical maxillary complete dentures were constructed from heat polymerized acrylic resin. These samples were subdivided into the following experimental subgroups in which each subgroup contains 5 samples for both acrylic and porcelain teeth and as follows: 1. Conventional flasking technique and immediate processing. 2. Conventional flasking technique and 6 hours delay in processing. 3. flasking technique with tension system and immediate processing. 4. flasking technique with tension system and 6 hours delay in processing. Reference metal pins were attached to the middle of the buccal surface of the upper right canine and center of the buccal groove of the left first molar. And according to these reference points on the teeth another metallic Reference pins were fixed on the denture vestibules and at a distance of 7.5mm by straight lines and 6.5mm where placed between the metal pins and the vestibules in order to standardize the measurement. The distance between the right and left metal pins on the canine and molars and the corresponding metal pins on the buccal vestibules were measured during the wax up stage and after processing by using an optical travelling microscope with an accuracy of 0.0005 mm. Means in (mm) were analyzed statistically by analysis of variance and the comparative T-test and least significance test (LSD). Results: Significant reduction in vertical displacement of the teeth occurred in groups when 6 hours delay in processing were applied, but a significant improvement was also observed in groups with tension system application when compared with control group. On the other hand, there were a high significant reduction in the vertical displacement in groups with tension system and 6 hours delay in processing combination. While for the type of artificial teeth data showed significant difference in the amount of vertical displacement of the teeth in groups with acrylic teeth when compared with porcelain teeth. Conclusions: The findings of this study showed that 6 hours delay in processing and tension system application were effective in reducing the vertical displacement of the artificial teeth during flasking. The maximum reduction in the displacement was observed in dentures constructed from acrylic teeth. On the other hand, significant decrease in vertical displacement of the teeth was detected in dentures constructed from porcelain teeth.
The current study shows the cytotoxicity effect of the Crassula ovata n-hexane extract on esophagus can¬cer. C. ovata is a perennial succulent plant belonging to the Crassulaceae family. In Africa, the leaves were used medicinally to cure epilepsy and diarrhoea by boiling them in milk. The hexane fraction, which is obtained through the maceration method, demonstrates the presence of many compounds that have an anticancer effect, which are ob¬tained by gas chromatography - mass spectroscopy. The phytosterol compound was isolated by a preparative thin layer chromato¬graph and was identified by liquid chromatography - mass spectroscopy. The hexane fraction was found to possess a strong anticancer effect against esophagus cancer. The
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The surface finish of the machining part is the mostly important characteristics of products quality and its indispensable customers’ requirement. Taguchi robust parameters designs for optimizing for surface finish in turning of 7025 AL-Alloy using carbide cutting tool has been utilized in this paper. Three machining variables namely; the machining speeds (1600, 1900, and 2200) rpm, depth of cut (0.25, 0.50, 0.75) mm and the feed rates (0.12, 0.18, 0.24) mm/min utilized in the experiments. The other variables were considered as constants. The mean surface finish was utilized as a measuring of surface quality. The results clarified that increasing the speeds reduce the surface roughness, while it rises with increasing the depths and fee
... Show MoreWe study the physics of flow due to the interaction between a viscous dipole and boundaries that permit slip. This includes partial and free slip, and interactions near corners. The problem is investigated by using a two relaxation time lattice Boltzmann equation with moment-based boundary conditions. Navier-slip conditions, which involve gradients of the velocity, are formulated and applied locally. The implementation of free-slip conditions with the moment-based approach is discussed. Collision angles of 0°, 30°, and 45° are investigated. Stable simulations are shown for Reynolds numbers between 625 and 10 000 and various slip lengths. Vorticity generation on the wall is shown to be affected by slip length, angle of incidence,
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Background: The present study was conducted to evaluate the effects of different bleaching methods on the shear bond strength of orthodontic Sapphire brackets bonded to human premolars teeth using light cured composite resin and to determine the predominant site of bond failure. Materials and Methods: Thirty freshly extracted human premolars were selected and randomly divided into three groups (10 per group). These groups are: control (unbleached) group, hydrogen peroxide group (HP) 37.5% ; which is the in- office bleaching method group, carbamide peroxide group (CP) 16%; which is the at- home bleaching method group. After bleaching process was performed, all the teeth stored in distilled water in a sealed container at room temperature for
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The liver is one of the largest glands in the digestive system and performs 13 various functions, including the secretion of hormones and enzymes. The gallbladder serves as a storage reservoir for secretions before they are released into the digestive system through the duodenum. The bile ducts branch from the liver’s lobes and ultimately connect to the digestive system, making this structure significant and distinct among different animal species. This review focuses on the differences between dogs and cats, highlighting the importance of these differences from both health and pathological perspectives. After conducting a detailed scientific review of the biliary tree in dogs and cats, we concluded that cats are more susceptible to the d
... Show MoreThe liver is one of the largest glands in the digestive system and performs 13 various functions, including the secretion of hormones and enzymes. The gallbladder serves as a storage reservoir for secretions before they are released into the digestive system through the duodenum. The bile ducts branch from the liver’s lobes and ultimately connect to the digestive system, making this structure significant and distinct among different animal species. This review focuses on the differences between dogs and cats, highlighting the importance of these differences from both health and pathological perspectives. After conducting a detailed scientific review of the biliary tree in dogs and cats, we concluded that cats are more susceptible
... Show MoreAbstract:
Organizations need today to move towards strategic innovation, which means the analysis of positions, especially the challenges faced by the change in the external environment, which makes it imperative for the organization that you reconsider their strategies and orientations and operations, a so-called re-engineering to meet those challenges and pressures. Now this research dilemma intellectual two-dimensional, yet my account in not Take writings and researchers effect strategic innovation in re-engineering business processes, according to science and to inform the researcher, and after the application represented in the non-application of such resear
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Background: Premature infant born with immature body system, their organs are not ready for extra uterine life, and they are unable to deal with external stress, which could alter body functions such as cardio-respiratory function. In addition, poor muscle tone increases the chance of developing an abnormal posture. To reduce this instability, applying developmental care such as nesting is vital to promote cardio-respiratory stability, maintain position, and reduce stress in preterm. Objectives: The study aims to assess the impact of the nesting technique on preterm cardio-respiratory parameters in various positions (supine, prone, and right lateral). Methodology: The research used randomized controlled trial des
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Global warming has a serious impact on the survival of organisms. Very few studies have considered the effect of global warming as a mathematical model. The effect of global warming on the carrying capacity of prey and predators has not been studied before. In this article, an ecological model describing the relationship between prey and predator and the effect of global warming on the carrying capacity of prey was studied. Moreover, the wind speed was considered an influencing factor in the predation process after developing the function that describes it. From a biological perspective, the nonnegativity and uniform bounded of all solutions for the model are proven. The existence of equilibria for the model and its local stability is inves
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