Background: Optimal root canal retreatment was required safe and efficient removal of filling material from root canal. The aim of this in vitro study was to compare the efficacy of reciprocating and continuous motion of four retreatment systems in removal of root canal filling material. Materials and Methods: Forty distal roots of the mandibular first molars teeth were used in this study, these roots were embedded in cold clear acrylic,roots were instrumented using crown down technique and rotary ProTaper systemize Sx to size F2 ,instrumentation were done with copiousirrigation of 2.5% sodium hypochlorite and 17% buffered solution of EDTA was used as final irrigant followed by distilledwater, roots were obturated with AH26 sealer and Protaper gutta-percha point F2 and medium fine accessory gutta-percha using lateral condensation technique,roots were left for 7 days with 100% humidity at 37ºC in an incubator. Roots were randomly divided into four groups according to technique used for removing the root filling material (ten teeth for each group): group I: reciprocating technique and Wave One system, group II: continuous technique and ProTaper retreatment system, group III: continuous technique and R-Endo system, group IV: continuous technique and D–RaCere treatment system. All the roots were radiographed before and after removal of gutta-percha from both bucco-lingual and mesiodistal directions using custom made platform and digital radiograph system RVG to havea digitized images. The total surface area of all root canals was measured before removal ofthe gutta-percha and the area of the remaining gutta-percha filling in the canals after retreatment procedure from both directions. These measurements were analyzed with Adobe Photoshop CS6 software, the percentage of removed gutta-percha calculated. Results: Statistical analysis was performed and the result showed group Ihad the highest mean values in removal of root canal filling material in both bucco-lingual and mesiodistal direction of dental radiograph and there were significant difference between group I and most of the other groups ,there were non significant difference between group II,group III and group IV. Conclusion: This study was showed all the used retreatment systems did notcompletely remove the root canal filling material. The reciprocating technique was most effective method for removing gutta-percha and sealer than continuous rotary technique
Autoría: Jehan Faris Yousif. Localización: Opción: Revista de Ciencias Humanas y Sociales. Nº. 89, 2019. Artículo de Revista en Dialnet.
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The research deals with a very important issue that affects women, an important segment of the society. This is because women are the basis of the family and the pillar of the society. Thus, the aim of the research is to examine the level and dimensions of the emotional and existential psychological crisis at the sample of the study. It further aims to investigate the statistical significant difference at the level of (0.05) regarding the feeling of the existential psychological crisis among battered and non-battered women. To reveal the objectives of the study, the researcher applied the existential psychological crisis scale to a sample of (72) women, divided into two groups: (35) battered women, who have been chosen purposefully. Thos
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This research deals with the financial reporting for the non-current assets impairment from the viewpoint of international accounting standards, especially IAS 36 "Impairment of assets”. The research problem focused on the non-compliance with the requirements of IAS 36 which would negatively affect the accounting information quality, and its characteristics, especially the relevance of accounting information, that confirms the necessity of having such information for the three sub-characteristics in order to be useful for the decisions of users represented
The support vector machine, also known as SVM, is a type of supervised learning model that can be used for classification or regression depending on the datasets. SVM is used to classify data points by determining the best hyperplane between two or more groups. Working with enormous datasets, on the other hand, might result in a variety of issues, including inefficient accuracy and time-consuming. SVM was updated in this research by applying some non-linear kernel transformations, which are: linear, polynomial, radial basis, and multi-layer kernels. The non-linear SVM classification model was illustrated and summarized in an algorithm using kernel tricks. The proposed method was examined using three simulation datasets with different sample
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In this paper, we propose a method using continuous wavelets to study the multivariate fractional Brownian motion through the deviations of the transformed random process to find an efficient estimate of Hurst exponent using eigenvalue regression of the covariance matrix. The results of simulations experiments shown that the performance of the proposed estimator was efficient in bias but the variance get increase as signal change from short to long memory the MASE increase relatively. The estimation process was made by calculating the eigenvalues for the variance-covariance matrix of Meyer’s continuous wavelet details coefficients.
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In this paper, we propose a method using continuous wavelets to study the multivariate fractional Brownian motion through the deviations of the transformed random process to find an efficient estimate of Hurst exponent using eigenvalue regression of the covariance matrix. The results of simulations experiments shown that the performance of the proposed estimator was efficient in bias but the variance get increase as signal change from short to long memory the MASE increase relatively. The estimation process was made by calculating the eigenvalues for the variance-covariance matrix of Meyer’s continuous wavelet details coefficients.
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Massive multiple-input multiple-output (MaMi) systems have attracted much research attention during the last few years. This is because MaMi systems are able to achieve a remarkable improvement in data rate and thus meet the immensely ongoing traffic demands required by the future wireless networks. To date, the downlink training sequence (DTS) for the frequency division duplex (FDD) MaMi communications systems have been designed based on the idealistic assumption of white noise environments. However, it is essential and more practical to consider the colored noise environments when designing an efficient DTS for channel estimation. To this end, this paper proposes a new DTS design by exploring the joint use of spatial channel and n
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The purpose of this resesrh know (the effectiveness of cooperative lerarning implementation of floral material for calligraphy and ornamentation) To achieve the aim of the research scholar put the two zeros hypotheses: in light of the findings of the present research the researcher concluded a number of conclusions, including: -
1 - Sum strategy helps the learner to be positive in all the information and regulations, monitoring and evaluation during the learning process.
2 - This strategy helps the learner to use information and knowledge and their use in various educational positions, and to achieve better education to increase its ability to develop thinking skills and positive trends towards the article.
In light of this, the
Abstract
To evaluate the effectiveness of Phenolic Compound of Salvia Frigida on induced atopic dermatitis (AD) of mice. Forty mice were included in the study, divided in to four groups (10 mice/group): apparently healthy, induced AD without treatment, induced AD treated with tacrolimus 0.1% ointment, and induced AD treated with Phenolic Compound of Salvia Frigida cream 5%. Examination of histopathology was done and skin homogenates levels also measured. Levels of WBC, Eosinophil, skin tissue homogenate of IL-13 and IL-4, serum IgE, and histopathological scores were significantly increased among induced non treated AD group in comparison with control group. Comparisons of non-treated induced AD
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The systems cooling hybrid solar uses solar collector to convert solar energy into the source of heat for roasting Refrigerant outside of the compressor and this process helps in the transformation of Refrigerant from the gas to a liquid state in two-thirds the top of the condenser instead of two-thirds the bottom of the condenser as in Conventional cooling systems and this in turn reduces the energy necessary to lead the process of cooling. The system cooling hybrid use with a capacity of 1 ton and Refrigerant type R22 and the value of current drawn by the system limits (3.9-4.2A), the same value of electric current calculated by the system are Conventional within this atmosphere of Iraq, and after taking different readings
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