Background: The aim of this study was to evaluate and compare the apical microleakage around retrograde cavities prepared with ultrasonic technique and filled with (Biodentine™) Materials and methods: 40 extracted single rooted human permanent maxillary teeth with mature apices were selected. The roots were prepared chemo-mechanically using k-files with crown-down technique and then obturated with lateral condensation gutta-percha technique. Teeth were divided into four main groups according to the cavity preparation method either manual or ultrasonic technique: Group A (n=10): A class I retrograde cavity at root end was prepared with traditional handpeice equipped and placement of Biodentine with manual condensation. Group B (n=10): A class I retrograde cavity at root end was prepared with Piezoelectric ultrasonic device equipped with ultrasonic tip with only manual compaction of the material. Group C (n=10): traditional handpeice and placement of Biodentine using both manual compaction and 5 second ultrasonic activation. Group D (n=10): Piezoelectric ultrasonic device and placement of Biodentine with both manual compaction and 5 second ultrasonic compaction. The teeth were immersed in 1% aqueous Methylene blue dye for 72 hr. Then they were sectioned longitudinally with a diamond disc and the depth of dye penetration was examined under high magnification 20X. Results: Statistical analysis showed a highly significant difference in microleakage among the tested groups in which Piezoelectric technique has proved superiority in retrograde cavity preparation and compaction of Biodentin when dye penetration scores were compared. So microleakage was highest with cavities prepared with handpeice and manual application of retrograde material group A (2.73±0.39) followed by microprepared cavities group C (1.86±0.16), and it was lowest with ultrasonically-prepared cavities group B (1.09±0.28) and group D (0.26±0.19). Conclusion: ultrasonic preparation produced significantly less microleakage than conventional method. Also less microleakage was observed with ultrasonic compaction of Biodentin when compared with conventional method of compaction.
The analysis of detective novels has taken different aspects. The linguistic analysis of them, for example, has tackled the linguistic systems of morphology, phonology, syntax, semantics, and pragmatics. In line with the linguistic analysis, this study explores the various pragmatic and stylistic devices realized through detective novels for the purpose of misdirecting and deceiving the reader. The problem is that when readers try to reach to the truth, they face difficulties. They might not reach to the right solution or infer wrong conclusions because writers use some techniques to hide the truth and mislead them. This study aims at examining these techniques and devices; namely, Grice's Maxims and ambiguity as pragmatic devices on the
... Show MoreThe conjunctive ''and'' and its Arabic counterpart ''و'' are discourse markers that express certain meanings and presuppose the presence of other elements in discourse. They are indispensable aids to both the text writers and readers. The present study aims to show that such cohesive ties help the writer to organize his main argument and communicate his ideas vividly and smoothly. They also serve as explicit signals that help readers unfold text and follow its threads as realized in the progression of context. The researcher has utilized the Quirk Model of Semantic Implication for data analysis. A total of 42 (22 for English and 20 for Arabic) political texts selected from different elite newspapers in both Arabic and English for the analy
... Show MoreDBN Rashid, International Journal of Innovation, Creativity and Change, 2020
The definition of "prostitute" and prostitution is a difficult one and a
question over which the legislators of many lands and nations differed. A
notable feature of prostitution is its epidemic increase at times of war,
revolution and armed commotion, on account of economic, social and
psychological factors generated by such conditions of mortal conflicts. Wars
invariably deprive young wives and lovers of their men folk, resulting in
financial , sexual and emotional frustrations . At no time is the natural
balance between the sexes more seriously disturbed than during wars, when
thousands of men are thrown into one sector of the country and hundreds of
towns and villages are left to women and children only. Lo
Identity is an influential and flexible concept in social sciences and political studies. The basic sense of identity is looking for uniqueness. In one sense, it is a sign of identification with those we assume they are similar to us or at least in some significant ways they are so. Globalization, migration, modern technologies, media and political conflicts are argued to have a crucial effect on identity representation in terms of the political perspectives specifically in the United States of America. This paper endeavors to investigate how American politicians represent their identities in speeches delivered in different periods of time namely from 2015 to 2018 in terms of the pragmatic paradigm. Three randomly selected speeches by fa
... Show MoreThis study examines emotional blackmail from a discursive pragmatic standpoint to gain insights into how this psychologically manipulative phenomenon is revealed in the discourse of some American movies. Five extracts from five American movies are purposely selected and analyzed using an eclectic model based on a discursive pragmatic approach to navigate this unexplored study area. The model incorporates Halliday’s (2014) transitivity system, Martin and White’s (2005) attitude system, Forward and Frazier’s (1997) types and tools of emotional blackmail, and Mayfield’s (2010) informal fallacies. The present study is guided by four research questions that identify the types and tools of emotional blackmail employed in the selec
... Show MoreNathaniel Hawthorne (1804-1864) has been widely known for his special interest in the female characters. In many of his novels, he narrates the conditions, values, and the institutions that surround and control the life of women, leading them to be victims. In “Rappaccini’s Daughter” (1844), the heroine, Beatrice is created to be victimized by her loved ones (her father and lover). This paper focuses on the term “victim,” it shows its aspects through the development of Beatrice’s character. The paper also studies a female character in the male-dominated society, to show the cruelty done to her, and how she is considered to be a second rate person, who is unable to live normally, or at least to save herself from dea
... Show MoreWith growing global demand for hydrocarbons and decreasing conventional reserves, the gas industry is shifting its focus in the direction of unconventional reservoirs. Tight gas reservoirs have typically been deemed uneconomical due to their low permeability which is understood to be below 0.1mD, requiring advanced drilling techniques and stimulation to enhance hydrocarbons. However, the first step in determining the economic viability of the reservoir is to see how much gas is initially in place. Numerical simulation has been regarded across the industry as the most accurate form of gas estimation, however, is extremely costly and time consuming. The aim of this study is to provide a framework for a simple analytical method to esti
... Show MoreThis research was conducted to measure the safety of heat stable enterotoxin a (STa) produced by enterotoxigenic Escherichia coli, through studying its toxic effect on human blood lymphocyte, since it showed a promising effect in reducing the proliferation of colorectal cancer cells. the cytogenetic effects of (STa) by using five different concentrations (100, 200, 400, 800 and 1600μg/ml) in comparison with negative (PBS, Phosphate buffer saline) and positive (MMC, Mitomycin C) at concentration of 5μg/ml, controls on human blood lymphocytes obtained from both (10) normal healthy persons and (20) colorectal cancer patients was measured by employing the following parameters: mitotic index, blast index, chromosomal aberrations and micronucle
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