Background: Proper cleaning and shaping of the whole root canal space have been recognized as a real challenge, particularly in oval-shaped canals.This in vitro study was conducted to evaluate and compare the efficiency of different instrumentation systems in removing of dentin debris at three thirds of oval-shaped root canals and to compare the percentage of remaining dentin debris among the three thirds for each instrumentation system. Materials and methods: Fifty freshly extracted human mandibular molars with single straight oval-shaped distal root canals were randomly divided into five groups of ten teeth each. Group One: instrumentation with ProTaper Universal hand instruments, Group Two: instrumentation with ProTaper Universal rotary instruments, Group Three: instrumentation with Revo-Srotary instruments, Group Four: instrumentation withTwisted rotary files and Group Five: instrumentation with Self-Adjusting Files (SAF). Sodium hypochlorite (3%) was used as an irrigant for all groups. After canals preparation, the roots were split longitudinally and photographed with a professional digital camera. The images of root sections were then magnified to 100x and the percentage of remaining dentin debris calculated for the apical, middle and coronal thirds by dividing the pixels occupied by debris at each third by the total pixels representing the entire area of the canal using Adobe Photoshop CS6. Data were analyzed statistically by ANOVA and LSD at 1% and 5% significant levels. Results: Both ProTaper hand and ProTaper rotary files resulted in significantly cleaner canals than Revo-S and Twisted rotary files at the middle and coronal thirds. The Self-Adjusting Files produced significantly cleaner canals at the three thirds than all the other groups. The coronal and middle thirds showed a greater amount of remaining dentin debris than the apical third for all groups except a non-significant difference found between the apical and middle thirds in SAF group. Conclusion: The Self-Adjusting Files allowed more efficient cleaning of oval-shaped root canals than hand and rotary instruments
Henrik Ibsen is considered one of the greatest writers on society and its problems in the modern era, as his works deal with society in all its forms in a realistic way, in which he presents the motives and consequences of social problems and their impact on society to study these problems through them to and propose solutions through theatre. Most of his writings were very serious about addressing these social issues. The method of collecting information in the study came through reviewing a group of sources related to realistic theater and social theory, then reading the plays covered in a critical and analytical reading. Based on that, the method of writing this study came and used a group of sources that directly relate to the s
... Show MoreThe aim of this research is to analyze Chaucer’s use of idealism in the “General Prologue” to The Canterbury Tales. Idealism is defined as a belief that ideals are the only true reality. Therefore, it stresses the mental or spiritual over the material objects.Idealism is widely used during the Middle Ages, especially by Geoffrey Chaucer, who is England’s most famous poet. The Canterbury Tales is his masterpiece. This Research analyzes ideals in the “General Prologue” toThe Canterbury Tales.
The conclusion of the present research shows that Chaucer uses idealism to criticize the follies and weaknesses of his age.Besides, he finds that adherence to ideal values is a means to cultivate morality leading to perfectio
... Show MoreThis paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results s
... Show MoreHydroxide upon the chemical composition and dry matter(DM) and organic matter(OM) digestibility . Rice straw was treated with 4% sodium hydroxide using 30% of DM basis moisture, and incubated at 40 ºC for 40 days., DM digestibility (DMD) was significantly affected (P<0.01) by the treatment , where DMD increased The objective of this experiment was to study the effect of physical form (long ,chopped and ground ) and washing rice straw treated with sodium from 42.32 to 45.41% , OM digestibility (OMD) and total digestible nutrient (TDN) increased(P<0.05) from 47.38 and 49.33 to 49.67 and 52.83% ,respectively. While hemicellulose content increased (P<0.05 ) from 261.71 to 268.17 gm/kg DM ,and metabolizable energy (ME) from 7.11 to 7.48 MJ/
... Show MoreThe problem of research was the lack of research that dealt with issue of the organizational environment, job design approach that is more suitable for knowledge work, therefore, the research aims to determine the impact of quality of working life and job enrichment on knowledge capital, starting from the hypothesis that there significant impact of quality of working life and job enrichment on knowledge capital, to achieve this goal the researcher from the theoretical literature and related studies conclude to the construction of the scheme shows the hypothetical relationship between the variables, which was adopted quality of working life and job enrichment as independent variable while knowl
... Show MoreThe five-a- Side Soccer for simple mental disability is as interesting and caring as many other sporting events. Therefore, the researchers believe that their basic skills tests are compatible with then level of the tested individuals in terms of age and mental ability. As a means of selecting those who are qualified to practice this game in a simple way, the problem of research has been identified in the design and standardization of two scoring skills that belong to this category and are approved by the training staff during the initial selection process. The research community is determined by people with mental disabilities who belong to the governmental and private institutes and the Special Olympics Union in Baghdad and for the year 2
... Show MoreThis study was conducted in order to statement the effect of ginger (Zingiber officinale) extracts in reducing the presence of the bacterium Salmonella typhimurium in some foods products.
Qualitative disclosures effective chemical compounds (alkaloids, flavonoids, phenols, tannins, terpenes) showed that the extracts of ginger an effective compounds as follows: oil extract and fresh juice> aqueous extract warm> aqueous extract cold. And studied the impact extract of fresh ginger juice, hot water ,cold water and oil rates extracts (1,2,3)% in bacteria test has shown that all s of extracts clear impact inhibition has oily extract of ginger recorded the highest value to inhibition zone reaching 35 mm when the concentration of 3%, f
The main objective of resources management is to supply and support the site operation with necessary resources in a way to achieve the required timing in handing over the work as well as to achieve the cost-realism within the budget estimated. The research aims to know the advantage of using GIS in management of resources as one of the new tools that keep pace with the evolution in various countries around the world also collect the vast amount of spatial data resources in one environment easily to handled and accessed quickly and this help to make the right decision regarding management of resources in various construction projects. The process of using GIS in the management and identification of resources is of extreme importance in t
... Show MoreA new method for determination of allopurinol in microgram level depending on its ability to reduce the yellow absorption spectrum of (I-3) at maximum wavelength ( ?max 350nm) . The optimum conditions such as "concentration of reactant materials , time of sitting and order of addition were studied to get a high sensitivity ( ? = 27229 l.mole-1.cm-1) sandal sensitivity : 0.0053 µg cm-2 ,with wide range of calibration curve ( 1 – 9 µg.ml-1 ) good stability (more then24 hr.) and repeatability ( RSD % : 2.1 -2.6 % ) , the Recovery % : ( 98.17 – 100.5 % ) , the Erel % ( 0.50 -1.83 % ) and the interference's of Xanthine , Cystein , Creatinine , Urea and the Glucose in 20 , 40 , 60 fold of analyate were also studied .