Background: Many studies have been conducted to evaluate the effect of using a hot material in the root canal and its potential for causing damage to the tooth supporting structure. Materials and methods: thirty permanent premolars were obturated with thermoplasticized Gutta-Percha using three different obturation techniques: soft core, Thermafil, and obtura to evaluate the rise in temperature on the root surface using a multipurpose digital thermometer. Results: temperature increases was significantly greater for Obtura versus Soft core (p<0.003), not significant for Thermafil versus Soft core (p<0.087), and Thermafil versus Obtura (p<0.125). Conclusions: temperatures rise on the root surface were below the critical level and, therefore, should not cause damage to the periodontal ligament.
Fiber‐reinforced elastic laminated composites are extensively used in several domains owing to their high specific stiffness and strength and low specific density. Several studies were performed to ascertain the factors that affect the composite plates’ dynamic properties. This study aims to derive a mathematical model for the dynamic response of the processed composite material in the form of an annular circular shape made of polyester/E‐glass composite. The mathematical model was developed based on modified classical annular circular plate theory under dynamic loading, and all its formulas were solved using MATLAB 2023. The mathematical model was also verified with real experimental work involving the vibration test of the f
... Show MoreAbstract: Under high-excitation irradiance conditions to induce fluorescence, the dependence of photobleaching of Coumarin 307 (C307) and acriflavine (ACF) laser dyes in liquid and solid phases have been studied. A cw LD laser source of 1 mW and 407 nm wavelength was used as an exciting source. For one hour exposure time, it was found that the solid dye samples suffer photobleaching more than the liquid dye samples. This is because in liquid solutions the dye molecules can circulate during the irradiation, while the photobleaching is a serious problem when the dye is incorporated into solid matrix and cannot circulate.
مع ان افلاطون في الفصلين السابع والعاشر من جمهوريته يعري المسرح بوصفه عالما زائفا يعج بالأخيلة التي يتوجب على المرء ان ينبذها ويتمسك بعالم الحقيقة، الا إن هذا لا يعدم الأثر البالغ الذي تركتهُ أرائهُ على المسرح، قديمهُ وحديثهُ،تجربهً وتنظيرا .إن حكايته الإستعارية للكهف ،والتي تعد مسرحةً للأفكارِ، إن هي إلا وسيلة ينفذ من خلالها الى جوهر المسرح. لذا فان مسرحية ونظرية الكهف قد اصبحت حجر الزاوية في ما قد اص
... Show MoreOur study comes up to clarify the role of television in spreading the culture of violence with a child. This study represents one of the important studies that have tried to highlight the impact of these programmes, particularly cartoons, on the child's behaviors, actions and acquired habits.Violence considers a common phenomenon among the people, as the role of the media, particularly TV has a vital role due to its properties, characteristics and its significant impact on different segments and groups in society and in children particularly through exposure to programmes of films.The results of the study have been affected by the rising proportion of females to males, and that the contribution of real life has a big role in the child ac
... Show MoreThe urban Gentrification is an inclusive global phenomenon to restructure the cities on the overall levels, the research to propose a specific study about the concept of urban Gentrification in the cities and showcasing its, specifications, and results, and how to deal with the variables that occur on cities through improvements as part of urban renewal projects, then the general axis of the research is shrinked, choosing the urban centers as the most important areas that deal with the urban Gentrification process due to its direct connection with indivisuals and social changes, and to process the specific axis of the research theses and studies will be showcased that discuss the topic in different research directions, and emerged
... Show MoreCantilever beams are used in many crucial applications in machinery and construction. For example, the airplane wing, the microscopic probe for atomic force measurement, the tower crane overhang and twin overhang folding bridge are typical examples of cantilever beams. The current research aims to develop an analytical solution for the free vibration problem of cantilever beams. The dynamic response of AISI 304 beam represented by the natural frequencies was determined under different working surrounding temperatures ((-100 ℃ to 400 ℃)). A Matlab code was developed to achieve the analytical solution results, considering the effect of some beam geometrical dimensions. The developed analytical solution has been verified successful
... Show MoreThe importance of knowledge is represented in the use of various sources of information, the corresponding to the same level of importance is the use of modern means and technologies in the delivery and investment of these sources to the beneficiaries, among these means and technologies are the multimedia that deal with most of the human senses, but the most important of which is sight and hearing, if these are invested the means in the field of education will give many positive results, such as the speed of receiving information, its clarity, and its freedom from impurities and influences, as well as its stability in memory as it is based on nderstanding, not memorization. On this basis, the experience of supporting the education process
... Show MoreChoosing an appropriate impression material is a challenge for many dentists, yet an essential component to provide an excellent clinical outcome and improve productivity and profit. The purpose of present study was to compare wettability, tear strength and dimensional accuracy of three elastomeric impression materials, with the same consistencies (light-body). Three commercially available light body consistency and regular set 3M ESPE Express polyvinylsiloxane (PVS), 3M ESPE Permadyne polyether (PE), and Identium (ID), impression materials were comparedTear strength test, contact angle test and linear dimensional accuracy were evaluated for three elastic impression material. Among the three experimental groups PE impression materia
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