Background: The aims of the study were to evaluate the unclean/clean root canal surface areas with a histopathological cross section view of the root canal and the isthmus and to evaluate the efficiency of instrumentation to the isthmus using different rotary instrumentation techniques. Materials and Methods:The mesial roots of thirty human mandibular molars were divided into six groups, each group was composed of five roots (10 root canals)which prepared and irrigated as: Group one A: Protaper system to size F2 and hypodermic syringe, Group one B: Protaper system to size F2 and endoactivator system, Group two A:Wave One small then primary file and hypodermic syringe, Group two B:Wave One small then primary file and endoactivator system, Group three A: step back technique to size 25 file as MAFand hypodermic syringe, Group three B: step back technique to size 25 file as MAFand endoactivator system . All the roots were sectioned at 2mm, 6mm ,12mm from the apex and studied by histopathological cross section. The degree of cleaning of each section was measured by the use of Autocade 2004 software system. Result :the least uncleaned isthmus surface area at coronal, middle and apical section was found by the Protaper system with endoactivator which represented the mean of the percentage of uncleaned surface area of 16.87%, 14.32% and 9.55% respectively. The system that produced least uncleaned canal wall was by Protaper system with endoactivator at coronal ,middle ,and apical sections of 12.21%, 9.14% and 18.55% respectively . The mean of highest percentage of increased canal diameter which was Protaper system, Wave One system and then step back. The comparison between the groups in the means which showed that the highest percentage of decrease in isthmus area was with the Protaper system, Wave One system and lastly the step back. Conclusions:The Protaper system with endoactivator was the best system in canal and isthmus cleaning.
The stress(Y) – strength(X) model reliability Bayesian estimation which defines life of a component with strength X and stress Y (the component fails if and only if at any time the applied stress is greater than its strength) has been studied, then the reliability; R=P(Y<X), can be considered as a measure of the component performance. In this paper, a Bayesian analysis has been considered for R when the two variables X and Y are independent Weibull random variables with common parameter α in order to study the effect of each of the two different scale parameters β and λ; respectively, using three different [weighted, quadratic and entropy] loss functions under two different prior functions [Gamma and extension of Jeffery
... Show MoreThis work describes the effect of temperature on the phase transformation of titanium dioxide (TiO2) prepared using metal organic precursors as starting materials. X-ray diffraction (XRD) was used to investigate the structural properties of TiO2 gels calcined at different temperatures (300, 500, 700) ?C. the results showed that the samples have typical peaks of TiO2 polycrystalline brookite nanopowders after calcined at (300 ?C), which confirmed by (111), (121), (200), (012), (131), (220), (040), (231), (132) and (232) diffraction peaks. Also, XRD diffraction spectra showed the presence of crystallites of anatase with low proportion of rutile phase where calcined at (500 ?C), while rutile phase domains at (700 ?C). The crystallite size of
... Show MoreCommunication represents the essence of language learning. Since the unspecified evolution of conveying information, human beings have been employing the main constituents of language with short pauses. Although the punctuation marks necessitate short expressions among thought group of words in writing, human language demand for understanding how and when to pause orally. This paper presents the pause technique in the classroom. It signifies the relation between pausing and lecturing in the class and determines its sufficient time-management to interact with college learners of different specializations. The conduct study reviewed teaching pause technique in the empirical studies at Special Education and Communication Disorders of Pennsylva
... Show MoreIt is doubtless that the sexual place has some common indicators due to the masculine and feminine bodies which may be natural or deviated (homosexual). The female has an act of voice in the imaginary masculine place whereas the male has an act of image recognized in the parental mind in both the secular and sacred place. Those places create different limits and perceptions according to the auditory and visual readings in search of identity, text and body in the feminine dramatic text.
The research includes four chapters; the first, the methodological framework, involves the problem which is centralized in the following enquiry: What is the relationship between the place and the term of
... Show More The feature that prevails in spoken political discourse - especially with regards to the fact
that it is otherwise used in the written one - is relatively high degree of formality. It is then just
logical that formality is usually accompanied with more polite forms and higher degree of
impersonality. Such discourse is characterized by the choice of specific vocabulary and syntactic
structures as well. However, there are some tendencies to bring political speech nearer to the
everyday discourse and that is why political speeches have been becoming more informal and
personal. Like any other types of discourse, the American political speeches are loaded with
deictic expressions that form an essential complementary
The purpose of the research is interpretation of what quality transformations In the Arab commercial banks' management, and determine which fields that have been achieved in the third millennium, and elicitation the governance trends for future vision to manage them and estimate the expected value for these transformations, the importance of the idea of research in investment the implicit and the apparent of practical knowledge stocks in the minds of managers by specialized language with the application of electronic business philosophy in response to the challenges of the information age and who should occupies those banks the center of Arab leadership and excellence, and try to upgrade to command centers in their co
... Show MoreThe Immanence in S. Abdu; Saboor Poetry
The aim of this research is to study the modern Spanish writings on the biography of Prophet Mohamed (PBUH), which gave the glorious biography its due by objective study and analysis with a scholarly approach, unlike the old Spanish and European oriental writings with its biased approach. In the past, Spanish and European writings on Prophet Mohamed were influenced by religious extremism and did not do any justiceto Prophet Mohamed. But this has changed in the modern times, and modern writing on the Prophet biography is based on objective analysis and reliance on original sources instead of the sources of the churches which were full of hate and wicked intentions to eliminate Islam.The research came to the conclusion that the modern Span
... Show MoreThe discipline of International Relations has been a science for almost a century and has undergone considerable development and dynamism as a field of knowledge. In the aftermath of the First World War, traditional idealistic trends prevailed. Still, after the end of the Second World War, the theory of realism dominated the analysis of international relations, international politics, and its laws and mechanisms. With the inter-paradigm debate of the 1980s, a broad spectrum of theories of international relations emerged, the most significant of which are critical theories including feminism. Feminist theory has since become central to the debates about global phenomena among those who work in International Relations as a field. The paper at
... Show MoreApplying the constructability concept in the construction industry has proven many benefits in different projects; however, this concept still lacks usage in Iraq. Therefore, it is important to encourage usage of the constructability concept in the construction industry in Iraq. The main purpose of this study is to investigate the factors that affect constructability in Iraq and then classify them according to their importance. A total of 37 factors were collected from an intensive literature review, and they were classified under the sub and main categories. A survey was undertaken in two sessions with open questionnaire and close questionnaire. The results were analysed and the mean