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
The purpose of this study was to evaluate the anesthetic effectiveness of a buccal infiltration technique combined with local massage (using 2% lidocaine) in the extraction of mandibular premolars to be utilized as an alternative to the conventional inferior alveolar nerve block.
Patients eligible included any subject with a clinical indication for tooth extraction of the mandibular 1st or 2nd premolars. All patients were anesthetized buccally by local infiltration technique followed by an external pressure applied for 1 min directly over the injection area. In each case, another local
Hands have consistently been an important vehicle in the transmission of disease (1). Thus, thorough hand-washing remains the single most important factor in preventing infection specially in hospitals and labs.Twenty-nine non-clinical volunteers (do not work or come in contact with a clinical or hospital setting) that lacked visible skin injuries, eczema or apparent skin disease were used, those subjects were all tested by a material of each of the three used in the study weekly and laboratory tests were done pre- and post washing.All three material were effective , Eugenol extract as effective as the bar and lotion soap. And this was confirmed statistically.Eugenol has a great antibacterial action even in small concentration and t
... Show MoreSurrealism is a twentieth-century literary and artistic movement oriented toward the liberation of the mind. Surrealism is a reaction to the philosophy of rationalism which was believed to be the cause of the disaster of World War I. It emphasizes the expression of the imagination as revealed in dreams and presented without conscious control, the unexpected juxtapositions of objects, the withdrawal of the self, and the exploitation of chance effects.
Surrealism began in Paris in the early 1920s, as Europe emerged from the devastation of World War I. A group of writers, artists, and filmmakers, led by the poet André Breton, adopted the word surréaliste (meaning, roughly, "super-real") as a label for their artistic activities. Influen
Purpose: the purpose of study is estimate the Risk premium, Interest rate, Inflation and FDI in the through of Coronavirus in the MENA countries. Theoretical framework: The theoretical framework included the study of the main variables, which are risk premium, interest rate, inflation, and foreign direct investment during the Corona virus pandemic. Design/methodology/approach: Concentrating on “COVID-19”, as an effective factor on the Foreign direct investment (FDI), I employ data of “MENA (Middle East and Northern Africa)” countries from 2000 to 2021 to investigate the impact of COVID-19, financial and macroeconomic indicators on FDI relying on the analytic research approach of Static panel data regression, includ
... Show MoreThe research aims to determine the role of training strategy dimensions of (trainers، curriculum training programs، trainees and their desire for training، administrative and supervisory services and their impact on the success of the training program) in the entrepreneurial performance of the organization dimensions of (pre-planning، renovation and modernization، efficiency، effectiveness)، so search ranks of great importance because it addresses an important and modern issue in performance entrepreneurial، and strategy training، aware of the importance of the subject and expected outcomes (General company for electrical Industries - motor plant) surveyed، was an analysis of data obtained through field visits in addition to the q
... Show MoreBackground Due to the intermittent, nonlinear, and uncertain behavior of renewable energy sources (res) such as solar and wind, grid stability and reliability require very high forecasting and optimization skills as widely reported in the literature. Traditional optimization methods work very well in small or static systems but are suffer difficulty on large-scale, dynamic and stochastic renewable environment due to their NP-hard nature. Methods The framework introduces the concept of a Machine Learning-Assisted Hybrid Cuckoo Search (ML-HCS) that combines CS with a hybrid metaheuristic and integrates Long Short-Term Memory (LSTM) networks for forecasting based on both regression models of LSTMs and hybrid optimization algorithm
... Show MoreExcess heat significantly reduces the efficiency and lifespan of electrical and optoelectronic devices. While passive radiative cooling is becoming more common, achieving active thermal control without physical reconfiguration remains challenging. Unlike conventional static absorbers, we propose a broadband plasmonic solar absorber designed to regulate energy absorption in the near-infrared (NIR) region without modifying the geometrical parameters. The design utilizes a coaxial cylindrical metal-insulator-metal (MIM) configuration, combining refractory copper (Cu), silicon dioxide (SiO2), and a trilayer graphene (Gr) that allows electrical tuning in a broadband solar absorber. Simulation results show a maximum broadband absorption efficienc
... Show MoreThis paper examines the decolonizing methods used by Leslie Marmon Silko in her novel Ceremony (1977) to heal the indigenous people from the patriarchal traditions of the white hegemony. This study aims to emphasize the vulnerable responses of the Pueblo people to the memories of the clan and to highlight Silko’s methods to sustain the history and lifestyle of the indigenous people. Therefore, Silko’s novel can be situated historically and culturally within memory-studies. To analyze the contrasting behaviors of characters, this paper projects the relationship between the collective patriarchal doctrines and that of the individual within the framework of memory studies. Theories of Jan and Aleida Assmann are used here to explore the
... Show MoreThe research aims at the identity of the accounting information and its characteristics, and then to study the possibility of using accounting information in rationalizing the decisions of capital expenditure. The study relied upon the descriptive analytical approach it is suitable to the nature of this study, the hypotheses of the study were tested by using a number of statistical methods by relying on statistical package program (SPSS), and the research concluded that the companies listed in Khartoum Stock Exchange using accounting information in the comparison between investment alternatives available and estimating the number of years required to recover of the investment cost, the challenges that cause weakness in using the
... Show MoreIn this research study the effect of fish on the properties optical films thickness 1200-1800 and calculated energy gap Basra direct transport permitted and forbidden to membranes and urged decreasing values ??of Optical Energy Gap increase fish included accounts optical also calculate the constants visual as factories winding down and the refractive index and reflectivity membranes also by real part and imaginarythe dielectric constant