Background: The purpose of this study was to evaluate and compare centering ability and canal transportation of simulated S-shaped canals instrumented with four different types of rotary nickel-titanium systems. Materials and Methods: Forty simulated S-shaped canals in resin blocks were divided into four groups of ten each and were instrumented to an apical size 25 by different instrumentation technique using ProTaper Universal files (group A), ProTaperNext (group B), Reciproc (group C) and WaveOne (group D).Centering ability and canal transportation was measured at (11) measuring points from D0 to D10 bysuperimposion of the pre- and post-operative images obtained by using digital camera in standardized manner. An assessment of the canals shape was determined using Photoshop CS2 and AutoCAD software. The data were analyzed statistically using ANOVA and LSD test. Results: In terms of centering ratio values, there was no statistically significant difference among the four groups at the coronal portion of the canals, with ProTaper system showing the least centering ability at all levels except at apical foramen. At the apical curvature, the Reciproc and WaveOne groups showed better centering ability than ProTaperNext and the difference was statistically highly significant among them at these points, while at the coronal curvature the ProTaperNext showed better centering ability than Reciproc and WaveOne. Canal transportation was seen in all groups but the ProTaper systems showed more transportation values at almost levels when compared with the other groups with the least values by ProTaperNext at the coronal curvature and the least values by Reciproc and WaveOne at the apical curvature. Conclusions: Under the conditions of this study, ProtaperNext ,WaveOne and Reciproc instruments maintained the original curvature significantly better than ProTaperUniversal at almost levels. ProtaperNext showed a better shaping ability than Reciproc and WaveOne at the coronal curved section while at apical curved section Reciproc and WaveOne showed a better shaping ability than ProtaperNext. Key words: centering ability, canal transportation, ProTaperNext, Reciproc, WaveOne.
A field experiment was carried out in one of the orchards of Al-Qassim district in Babel Governorate to find out the ability of a locally manufactured platform to serve palm trees by working in flat and uneven orchard land, palm tree heights of 4, 8, and 12 meters, and it performs pollination, pruning and harvesting services. The time of ascent and descent, the palm service, and the palm/hour productivity were measured. A randomized complete block design with three replications used a split split-plot arrangement. The nature of the land (flat or uneven) represented the main plots, the height of the palm trees (4, 8, 12) meters, the sub-plots, and the palm service operations (pollinati
In this work, the effect of aluminum (Al) dust particles on the DC discharge plasma properties in argon was investigated. A magnetron is placed behind the cathode at different pressures and with varying amounts of Al. The plasma temperature (Te) and density (ne) were calculated using the Boltzmann equation and Stark broadening phenomena, which are considered the most important plasma variables through which the other plasma parameters were calculated. The measurements showed that the emission intensity decreases with increasing pressure from 0.06 to 0.4 Torr, and it slightly decreases with the addition of the NPs. The calculations showed that the ne increased and Te decreased with pressure. Both Te and ne were reduced by increasing
... Show MoreThe research aims to find out the impact of wages and benefits systems on the performance of employees, which included the research community on a sample of employees in the company, and the sample consisted of (50) employees and an employee, A questionnaire composed as prepared (23) paragraph, use the promised statistically methods in data collected by the questionnaire analysis. The research reached a number of results, the most prominent of which were: There is a correlation between wage systems, benefits and performance of employees, and the presence of the impact of the systems of wages and benefits to the performance of employees. The research was presented a set of recommendations including: increasing the effectiveness of
... Show MoreDespite the global economic downturn, online e-commerce, especially the sale of counterfeit goods, continues to witness a rise in sales, and one of the important players in e-commerce is the owners of e-commerce auction sites. Although they do not have a direct role in trademark infringement, they still consider them indirectly responsible (secondary liability) for infringing on their trademarks. Thus, many cases have been filed by the owners of the original trademarks (which have been infringed by persons who have sold some of the goods and products that are imitating their marks through some electronic auctions) against the owners of those auctions. In view of the international character of the Internet, in different countries, and despit
... Show MoreThis study aims to reveal the semiotic of “March of Return” cartoon in the Palestinian journalism, topics, Symbols and semantics that were covered.
This study is descriptive. It uses the survey method. Content analysis, and methodological comparison was also used.
The researcher chose an intentional sample of Palestine and Al-Hayat Al-Jadida newspapers for one year from March 30, 2018 to March 31, 2019, through a comprehensive inventory of all cartoons of the return marches during this period, which amounted to 59 cartoons.
The study has reached the following findings:
Newspapers cartoons focused on the topics of durability of the protester
... Show MorePurpose: The purpose of this study was to compare the outcomes of 2 different anesthetic techniques (local infiltration vs infraorbital nerve block) for eliminating pain during apical surgeries that are associated with extensive periapical pathology in the anterior maxilla. Materials and Methods: Patients were randomly divided into 2 groups: patients in group I were anesthetized labially by local infiltration injections, whereas those in group II received a single infraorbital nerve block. Palatal injections were given for the 2 groups. Once the pain was initiated during surgery, the procedure was discontinued until profound anesthesia was secured. The studied variables were age, gender, onset of anesthesia, operative time, and intraoperati
... Show MoreMany industrial systems involve multiple criteria and objectives, and they are very complex problems in computational science, such as task scheduling. We propose bi-criteria and bi-objective scheduling problems, which are solved by two nature-inspired evolutionary algorithms, such as Simulated Annealing (SA) and Bee Algorithm (BA). This problem is characterized by scheduling a batch of tasks on multiple machines, and it is fundamental because the solution should focus on the simultaneous optimization of two conflicting objectives: the makespan minimization and the total tardiness minimization. This problem is NP-Hard, and therefore, two evolutionary methods were used to search for solutions intelligently in this huge, very complex
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