Background: Irrigation of the canal system permits removal of residual tissue in the canal anatomy that cannot be reached by instrumentation of the main canals so the aim of this study was to compare and evaluate the efficiency of conventional irrigation system, endoactivator sonic irrigation system,P5 Newtron Satelec passive ultrasonic irrigation and Endovac irrigation system in removing of dentin debris at three levels of root canals and to compare the percentage of dentin debris among the three levels for each irrigation system. Materials and methods: Forty extracted premolars with approximately straight single root canals were randomly distributed into 4 tested groups of 10 teeth each. All canals were prepared with Protaper Universal hand files to size #F4, and irrigated with 2.5% NaOCI 1 ml between files and 5ml for 60 seconds as a final irrigant by different irrigation devices; group one, by using conventional system; group two, by using Endoactivator sonic irrigation system, group three, by using Satelec Passive Ultrasonic irrigation and group four by using the Endovac system. After the final irrigation, the roots were split longitudinally and photographed with a digital microscope. The roots were magnified to 100X; a percentage of debris was calculated for the apical 0-3, middle 3-6 and coronal 6-9 mm. The debris score was calculated as a percentage of the total area of the canal that contained debris as determined by pixels in Adobe PhotoshopCS5. Data were analyzed statistically by ANOVA and LSD at 5% significant level. Results: when comparing the debris remaining, the Endovac, Endoactivator and Satelec groups showed significantly less debris than the conventional group at all three levels (p < 0.01). The Endovac group showed significantly less debris than the Endoactivator group at middle and coronal levels while no significant difference found between the Endovac system and Endoactivator system at apical level. The apical 0-3 mm showed significantly more debris than both the middle and coronal level for all groups. Conclusion: The EndoVac system showed a higher cleaning capacity of the canal at all levels, followed by the protocols that used Endoactivator sonic irrigation system. The conventional irrigation system with maxi-i-probe needles showed inferior results. The apical three millimeters showed a greater amount of debris than the 3-9 millimetres from the working length, regardless of the irrigation device used.
Physical and chemical adsorption analyses were carried out by nitrogen gas using ASTM apparatus at 77 K and hydrogen gas using volumetric apparatus at room temperature, respectively. These analyses were used to determine the effect of coke deposition and poisoning metal on surface area, pore size distribution, and metal surface area of fresh and spent hydrodesulphurization catalyst Co-Mo\Al2O3 . Samples of catalyst (fresh and spent) used in this study are taken from AL-Dura refinery. The results of physical adsorption shows that surface area of spent catalyst reduced to third compare with fresh catalyst and these catalysts exhibit behavior of type four according to BET classification ,so, the pores of these samples are cylindrical, an
... Show Moredrosophila larvare of diffrent speces were subjected to this in order study the structure of cephalopharyngeal armature and mouth more hooks dentition the lines number among
The Esterification kinetics of acetic acid with ethanol in the presence of sulfuric acid as a homogenous catalyst was studied with isothermal batch experiments at 50-60°C and at a different molar ratio of ethanol to acetic acid [EtOH/Ac]. Investigation of kinetics of the reaction indicated that the low of [EtOH/Ac] molar ratio is favored for esterification reaction, this is due to the reaction is catalyzed by acid. The maximum conversion, approximately 80% was obtained at 60°C for molar ratio of 10 EtOH/Ac. It was found that increasing temperature of the reaction, increases the rate constant and conversion at a certain mole ratio, that is due to the esterification is exothermic. Activity coefficients were calculated using UNIFAC progra
... Show MoreIn the name of God the Merciful
After .....
This is discussed in the hadeeth of Shaaban's speech, in which there is much talk in modern terms about the ruling
It has to be corrected, improved, weakened or denied, and it has a title (modern)
Shaaban's sermon is a modern study). It is an attempt to judge me after I come
In the text and then came out of the books and works that mentioned the sermon in its verses and then a statement of the ruling
And then I studied the rules and ruled them according to the rules
Followed by the scientists wound and amendment, and then the conclusion and deposited the most important results that came out
He accepts this purely for his generous consideration of this humble research, an
Physical and chemical adsorption analyses were carried out by nitrogen gas using ASTM apparatus at 77 K
and hydrogen gas using volumetric apparatus at room temperature respectively. These analyses were used for
determination the effect of coke deposition and poisoning metal on surface area, pore size distribution and
metal surface area of fresh and spent hydrodesulphurization catalyst Co-Mo\Al2O3 .
Samples of catalyst (fresh and spent) used in this study are taken from AL-Dura refinery.
The results of physical adsorption shows that surface area of spent catalyst reduced to third compare with
fresh catalyst and these catalysts exhibit behavior of type four according to BET classification ,so, the pores
of these sample
The aim of the research is to know the effect of a training program based on interactive teaching strategies on achievement and creative problem solving among fourth-grade students in chemistry of the directorate of education Rusafa first, the sample was divided into two groups, one experimental and numbering (29) students and the other control group numbering (30) students. The experimental group underwent the training program in the first semester of the year (2021-2022) and the control one studied according to the usual method. Two tools were built, the first being an academic achievement test consisting of (40) multiple-choice items, and the second a test of creative problem-solving skills in a chemistry subject and consisting o
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