Background: The new concepts and technologies continue to change the dynamics of endodontic practices in the world. Rapid and significant changes in techniques, instrument design, and the type of metals used to manufacture endodontic instruments which have been made during the last few years in an attempt to overcome canal preparation errors. The purpose of this study is to measure and compare canal transportation and centering ability of Self Adjusting File with two rotary nickel-titanium (Ni-Ti) systems, ProTaper and BioRaCe at different levels. Material and Methods: Forty five distal roots of mandibular first molars with moderate curvature were selected using Schneider method. Roots were divided randomly into 3 groups of 15 each and were scanned using Computed Tomography (Initial scan). After canal preparation with ProTaper (group A), BioRaCe (group B), and Self Adjusting File (group C) the roots were rescanned (Final scan), the degree of canal transportation and centering ability were assessed at apical (4 mm), middle (6 mm), coronal (9 mm) sections using computed tomography. The collected data were statistically analyzed using ANOVA and Least Significant Difference tests. Results: There were no statistically significant differences among the groups at level 4 mm and level 9 mm (P ? 0.05). However, at level 6 mm there was a highly significant difference between (A) and (B) groups (P ? 0.01) and there was a significant difference between (A) and (C) groups (P ? 0.05). There were no statistically significant differences among different levels of (A) and (C) groups (P ? 0.05), while (B) group showed a highly significant difference between 4 mm and 9 mm levels and between 6 mm and 9 mm levels (P ? 0.01). Regarding canal centering ability, there was no statistically significant difference among the three groups at different levels (P ? 0.05)., while (B) group showed a significant difference between 4 mm and 9 mm levels (P ? 0.05), and a very highly significant difference between 6 mm and 9 mm levels (P ? 0.001). Conclusion: The study demonstrated that canal preparation with the three designs of Ni-Ti instruments produced canal transportation. Self Adjusting File group showed less canal transportation than ProTaper group. There was a comparable value of canal centering ability among different levels in each group except in BioRaCe group.
Plagiarism is becoming more of a problem in academics. It’s made worse by the ease with which a wide range of resources can be found on the internet, as well as the ease with which they can be copied and pasted. It is academic theft since the perpetrator has ”taken” and presented the work of others as his or her own. Manual detection of plagiarism by a human being is difficult, imprecise, and time-consuming because it is difficult for anyone to compare their work to current data. Plagiarism is a big problem in higher education, and it can happen on any topic. Plagiarism detection has been studied in many scientific articles, and methods for recognition have been created utilizing the Plagiarism analysis, Authorship identification, and
... Show MoreFind cares studying ways in the development of industrial products and designs: the way the progressive development (how typical) and root development (jump design), was the aim of the research: to determine the effectiveness of the pattern and the jump in the development of designs and industrial products. After a process of analysis of a sample of research and two models of contemporary household electrical appliances, it was reached a set of findings and conclusions including:1-leaping designs changed a lot of entrenched perceptions of the user on how the product works and its use and the size and shape of the product, revealing him about the possibilities of sophisticated relationships with the product, while keeping the typical desi
... Show MoreThe study aims to identify the level of cognitive beliefs, as well as to identify the level of self-organized learning strategies among intermediate school students. The study also aims to identify the differences in the level of self-organized learning strategies among intermediate school students in term of gender, branch (scientific, literary). In order to achieve the research objectives, the researcher designed a scale to measure the cognitive beliefs. As for the scale of self-organized learning strategies, the researcher adopted a scale of (Pintrich et al. 1991), which was translated by (Izzat Abdelhamid, 1999) , For self-organized learning strategies, the sample consisted of (400) students from the research population, whic
... Show MoreSome of the issues that have become common in our society recently after the Americans entered our country and were rubbed by some security agencies: obtaining some information from children, and the serious consequences that may lead to the lives of innocent people, became common interrogation of some security agencies and rely on their words.
There are significant cases where their testimony needs to be heard, such as their presence in some places where incidents are not witnessed by others, such as schools or being witnesses to certain crimes.
I saw the study of this case in the light of Sharia and law
This research aims to know the role of transformational leadership in the organizational success of the College of Education at Samarra University. The researcher adopted the analytical descriptive method in analyzing the research problem. The research included two main hypotheses that resulted in four hypotheses that were subjected to statistical tests. A sample of (54) The researcher used the survey method as a main tool for collecting data and information as well as visits and structured interviews that took place during the period of application. The research reached a set of conclusions and recommendations among the conclusions that there is an art relationship There is a strong and moral impact between transformational lead
... Show MoreBackground: Esthetic treatment is the options of patient seeking orthodontic treatment. Therefore this study was conducted to measure the concentration of Aluminum, Nickel, Chromium and Iron ions released from combination of monocrysralline brackets with different arch wires immersed in artificial saliva at different duration, to evaluate the corrosion point on different parts of the orthodontic appliances before and after immersion in artificial saliva, and to evaluate the corrosion potential of each group of the orthodontic appliances. Material and methods: Eighty orthodontic sets prepared. Each set represents half fixed orthodontic appliance, from the central incisor to the first molar, for the maxillary arch, each set consisted of molar
... Show MoreBackground: Several risk managem-ent standards had been developed including the Project Management Institute, the National Institute of Standards and Technology, actuarial societies, and ISO standards.
Objective: The study aimed at evaluating risk management among managers of model and ordinary primary health care centers in Baghdad City and comparing the risk management among these centers.
Methods: A descriptive comparative des
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Abstract
The Classical Normal Linear Regression Model Based on Several hypotheses, one of them is Heteroscedasticity as it is known that the wing of least squares method (OLS), under the existence of these two problems make the estimators, lose their desirable properties, in addition the statistical inference becomes unaccepted table. According that we put tow alternative, the first one is (Generalized Least Square) Which is denoted by (GLS), and the second alternative is to (Robust covariance matrix estimation) the estimated parameters method(OLS), and that the way (GLS) method neat and certified, if the capabilities (Efficient) and the statistical inference Thread on the basis of an acceptable
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