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
The research aims to design an electronic program that allows users to assess the possibility of different practices for projects management professional according to the PMBOK methodology)) and using the requirements Data mentioned in the "knowledge and experience in project management Evaluation guide" issued by the professional Institute of project management According to the results of this program will be electronic The possible classification of project management in terms of both (proficiency_ perform tasks) as less than the desired level or within or above average in terms of best practices, and finally a number of recommendations to overcome the possible shortcomings. The most important is the need to enrich the service
... Show MoreSUMMARY. The objectives of the present study were to assess the possible predictors of COVID-19 severity and duration of hospitalization and to identify the possible correlation between patient parameters, disease severity and duration of hospitalization. The study included retrospective medical record extraction of previous coron avirus COVID-19 patients in Basra hospitals, Iraq from March 1st and May 31st, 2020. The information of the participants was investigated anonymously. All the patients’ characteristics, treatments, vital signs and laboratory tests (hematological, renal and liver function tests) were collected. The analysis was conducted using the SPSS (version 22, USA). Spearman correlation was used to measure the relations
... Show MoreThe oil and gas production industry is considered the most important industries in the modern world because of its large relative significance among the group of energy recourses required for the world, where the natural resources represent the oil and natural gas fields, phosphate, gold, coal, forests and others. The most important advantage of the natural resources is its need for huge financial investments for a relatively long period of time from the beginning of the work until the start of extracting natural resources. Also, there are numerous cases where the natural source is not feasible exploited economically and is not discovered until after the passage of a long period of time from the start of work and paying relatively high a
... Show MoreThe investment environment is the incubator for all types of domestic and foreign investments, so if their determinants are encouraging, they increase the levels of investment flows and vice versa, as there is a relationship between the nature of the investment environment and the level of investment flows, and the determinants of the investment environment are numerous and the most important of which are security and political stability, and economic and financial factors that include relative stability In the exchange rate and inflation rates, the availability of banks and their development, transparency and integrity in administrative dealings and the lack of prevalence of administrative and financial corruption, and the clari
... Show MoreThe concept of deficit in public budget becomes a chronic economic phenomenon in most of the world, whether the advanced countries or developing countries. Despite the difference in the visions of the economic schools to accept or reject the deficit in public budget but the opinion that prevailed is the necessity of the state to reduce the public spending which led to a continuous deficits in the public budget which consequently increased the government borrowing ,increase income taxes and wealth, consequently this weakened the in motivation in private investment which contributed to the increase of in factionary stagnation , so that governments have to cover the lack of local funding sources which become difficult to be eq
... Show MoreThree different types of nozzles (different wear rate) were used in this study. They are classified depending on the severity of their wear to three groups: new, worn and damaged nozzles. Those nozzles were spraying with the same application rate (303 l/ha) on two-year field trials; this was achieved by changing the spraying pressure for each group of nozzles in order to get the same application rate. This practice is usually done by operators of sprayers, who calibrate the sprayers on the same application rate every year without changing the nozzles, so they tend to reduce the spraying pressure in order to compensate the flow rate increase due to the nozzles yearly wear. Two types of
In the recent decade, injection of nanoparticles (NPs) into underground formation as liquid nanodispersions has been suggested as a smart alternative for conventional methods in tertiary oil recovery projects from mature oil reservoirs. Such reservoirs, however, are strong candidates for carbon geo-sequestration (CGS) projects, and the presence of nanoparticles (NPs) after nanofluid-flooding can add more complexity to carbon geo-storage projects. Despite studies investigating CO2 injection and nanofluid-flooding for EOR projects, no information was reported about the potential synergistic effects of CO2 and NPs on enhanced oil recovery (EOR) and CGS concerning the interfacial tension (γ) of CO2-oil system. This study thus extensively inves
... Show MoreBackground: Repeated teenage pregnancy is a major burden on the healthcare system worldwide. Objective: We aimed to compare teenagers with their first and third pregnancies and to evaluate the likelihood of neonatal complications. Materials and Methods: This cross-sectional study was performed on female teenagers (aged ≤ 19 yr) with singleton pregnancies. The subjects (n = 298) were screened over 12 months. Ninety-six women were excluded, based on the exclusion criteria. The remaining subjects (n = 202) were divided into two groups: teenagers with first pregnancy (n = 96) and teenagers with third pregnancy (n = 47). The subjects were observed throughout pregnancy and delivery. The final sample size of the first and thi
... Show MoreAspect categorisation and its utmost importance in the eld of Aspectbased Sentiment Analysis (ABSA) has encouraged researchers to improve topic model performance for modelling the aspects into categories. In general, a majority of its current methods implement parametric models requiring a pre-determined number of topics beforehand. However, this is not e ciently undertaken with unannotated text data as they lack any class label. Therefore, the current work presented a novel non-parametric model drawing a number of topics based on the semantic association present between opinion-targets (i.e., aspects) and their respective expressed sentiments. The model incorporated the Semantic Association Rules (SAR) into the Hierarchical Dirichlet Proce
... Show MoreABSTRACT
The research aims to identify the role of scientific planning of inventory by determining the quantity of economic demand and the number of times of purchase and associated annual total costs to achieve a sufficient and appropriate level of inventory . The research was based on the case study methodology. Materials of increasing demand in the Institute of Technical Management and knowledge of the degree of conformity of the procurement plan with the standard indicators adopted in a scientific method ,its include economic order quantity and number of purchasing times .
one of The main results of the research was the existence of a large difference between the quantity of the economic purchase of ea