Background: Dimensional changes of acrylic denture bases after polymerization results in need for further adjustments or even ends with technical failure of the finished dentures. The purpose of this study was to estimate the linear dimensional changes for different palatal depths when using multiple investment materials and polymerization techniques. Materials and methods: Ninety upper complete denture bases were constructed for this study. They were divided into two main groups according to the polymerization methods: conventional water bath and experimental autoclave (short and long cycles). Each main group was further subdivided into three subgroups according to the palatal depth (shallow, medium and deep). Furthermore, for each palatal depth; complete denture bases were invested either with dental stone or laboratory silicone. For each upper complete denture, measurements of linear dimensional changes were done by fixation of metallic screws on the tissue surface of the denture base. The distances were measured by using travelling microscope with an accuracy of 0.001 %. The data were statistically analyzed using three way analysis of variance (ANOVA) for three variables, which were (palatal depth, investments and polymerization techniques), LSD test and student T test for comparisons between groups. Results: There were significant improvements in the dimensional accuracy of denture bases cured with autoclave compared with water bath. Also, silicone investments were a successful alternative to stone, study data shows that short autoclave processing with silicone reduces the magnitude of the linear dimensional changes. On the other hand, long autoclave processing and stone investments were better than silicone in reducing dimensional changes. Conclusion: The findings of this study indicates that the use of autoclave processing in acrylic curing is a promising alternative to the conventional water bath and leads to better dimensional stability for the finished dentures in all oral configurations and palatal depths. Also, Silicone is more preferable than stone, although it's not as strong investing materials when compared with stone.
Biomedical alloy 316L stainless steel enhancing to replace biological tissue or to help stabilize a biological structure, such as bone tissue, enhancing were coated with deposition a thin layer of silver nanoparticles as anti-bacterial materials by using DC- magnetron sputtering device. The morphology surface of The growth nanostructure under the influence of different working pressure were studied by atomic force microscope. The average grain size decrease but roughness of the silver thin layer was increased with‖ ―increasing the working pressure. The thickness of silver thin layer was increased from 107 nm at 0.08 mbar to 126 nm at 1.1 mbar. Antimicrobial activity of silver thin layers at different working pressure were studied. Th
... Show MoreThe aim of this research is to employ the roundhouse strategy to study its impact on the students achievement of the 10th grade in physics and their core thinking. After the application of the research experience and gaining data, which was processed statistically using the statistical packages program (SPSS). The results of the researcher revealed the superiority of the students of the experimental group who studied using the roundhouse strategy on the students of the control group who studied the usual method in the achievement test. As results showed that there were statistically significant differences between the average scores of the experimental group and the average scores of the control group students in the core thinking test and
... Show MoreIlliteracy has spread in the last years, although it was eliminated in the 1980s. The return of illiteracy brings ignorance, illness, backwardness and regression among nations. It has taken many types, mainly alphabetical, scientific and computer illiteracy. Hence, the increasing nature of illiteracy has attracted the attention of governments and societies alike. This may touch the reality of societies starting with their youth unless those, who are in charge, will find workable solutions for the existing problems. The results of the study revealed that there is a real disaster awaiting the next generation after years of stray, and ignorance of the people in charge who are too engaged in getting their privileges to care about this proble
... Show MoreS Khalifa E, AH Khalil I, N Adil A, AB Razan A…, 2009
A total of 215 sheep and 87 goats were carefully searched for ixodid ticks from January to December 2015 at different regions of the middle and south of Iraq. The detached ticks count 1533 ticks from sheep with intensity of 8.4 and count 332 ticks from goats with intensity of 6.8. Tick species recovered from sheep and their incidence rates were: Rhipicephalus turanicus (39%), Hyalomma anatolicum (28%), R. (Boophilus) annulatus (11%), Hyalomma sp. (9%), H. turanicum (6%), H. excavatum (6%) and R. leporis (1%) while the tick species recovered from goats and their incidence rates were: R. turanicus (64%), H. anatolicum (24%)
... Show MoreLandlocked countries are displayed geopolitical new geo-political and intended to
countries that do not have sea views, a phenomenon present in four continents of the world
are: Africa, Europe, and Asia, and South America and the number arrived at the present time
to the (44) state the largest number of them in the continent it arrived in Africa (16) countries
in Asia (13) countries and Europe (13) In the State of South America two. This phenomenon
emerged due to the division of federations and empires and colonial treaties and others. But
the negative effects suffered by these countries may vary from one country to another, since
these countries in the continent of Europe, for example, is different from the same cou
Complex and complex psychological processes are complexand are the result of convergence, convergence and interaction between variables, including the subject of mediation or group or individual and psychological processes involved in the variance, including - personal knowledge and emotional tone (Osman, 1987, p. 8 ). An emotionally balanced individual has the ability to endure and delay meeting needs and has the ability to endure as much as possible. Of the emotional balance of the individual is characterized by emotional stability, show some signs of emotional agitation toward any kind of opposition, anger and realism in self-life and discipline (Swift, 1996, p. 44) Van, et al. , Indicates that people with low emotional balance,
... Show MoreThe research revolves around the views of Al-Amadi and Al-Jurjani in the metaphors in their books, balancing Abu Tammam and Al-Bohtari, and mediation between Mutanabi and his opponents. And others whose poems were cited. One of the most important things we have reached is: the critics release the term metaphor to take sometimes and mean to take the meaning or steal it, and analyzed the evidence of metaphor as a rhetorical art in the light of what he heard about the former Arab poets, rejected the unusual metaphor out of use, and reclaimed the familiar metaphor. The research after submitted to the topics are: the first: Al-Amadi and his budget book, the second: Al-Jurjani and his book of mediation, and the third is divided into three dema
... Show MoreThis is an open access by CC Attribution-Noncommercial-NoDerivatives 4.0
https://creativecommons.org/licenses/by-nc-nd/4.0
Takfir is an ancient phenomenon that accompanied the emergence of Islam, and this phenomenon took its political dimension during the time of the fourth Rashidi Caliph with the emergence ofthe Kharijites sect that disbelieved many Muslims.
The study started from the hypothesis that "contemporary Islamicmovements and organizations have relied in their takfir on the ideas and fatwas presented by the predecessors which applied ontocontemporary rea
... Show MoreAbstract:
The research aims to identify how to audit potential liabilities and contingent liabilities in light of the pandemic and its reflection on the auditor's report. The research problem is represented by the complexity of the process of checking potential liabilities and contingent liabilities in insurance companies, which was negatively reflected in the auditor's neutral technical opinion. The researchers hypothesize that auditing potential liabilities and contingent liabilities in light of the Corona pandemic is positively reflected in the auditor's report. The research concludes that the process of checking potential liabilities and contingent liabilities is
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