Background: The aim of this study was to evaluate and compare the apical microleakage around retrograde cavities prepared with ultrasonic technique and filled with (Biodentine™) Materials and methods: 40 extracted single rooted human permanent maxillary teeth with mature apices were selected. The roots were prepared chemo-mechanically using k-files with crown-down technique and then obturated with lateral condensation gutta-percha technique. Teeth were divided into four main groups according to the cavity preparation method either manual or ultrasonic technique: Group A (n=10): A class I retrograde cavity at root end was prepared with traditional handpeice equipped and placement of Biodentine with manual condensation. Group B (n=10): A class I retrograde cavity at root end was prepared with Piezoelectric ultrasonic device equipped with ultrasonic tip with only manual compaction of the material. Group C (n=10): traditional handpeice and placement of Biodentine using both manual compaction and 5 second ultrasonic activation. Group D (n=10): Piezoelectric ultrasonic device and placement of Biodentine with both manual compaction and 5 second ultrasonic compaction. The teeth were immersed in 1% aqueous Methylene blue dye for 72 hr. Then they were sectioned longitudinally with a diamond disc and the depth of dye penetration was examined under high magnification 20X. Results: Statistical analysis showed a highly significant difference in microleakage among the tested groups in which Piezoelectric technique has proved superiority in retrograde cavity preparation and compaction of Biodentin when dye penetration scores were compared. So microleakage was highest with cavities prepared with handpeice and manual application of retrograde material group A (2.73±0.39) followed by microprepared cavities group C (1.86±0.16), and it was lowest with ultrasonically-prepared cavities group B (1.09±0.28) and group D (0.26±0.19). Conclusion: ultrasonic preparation produced significantly less microleakage than conventional method. Also less microleakage was observed with ultrasonic compaction of Biodentin when compared with conventional method of compaction.
That the child in the early years of his life learns a lot of experiences that help him
grow properly, and if the availability of the child family atmosphere full of love and affection
and trust he was able to grow healthy growth and is in accordance with itself and with the
community in which they live, and stop method of the child in the expression of fear on the
nature of situation and on the theme of fear and the reaction of those around the child as well
as the vague positions that can not a child from its interpretation raises his fear, and its lead in
life are the kindergarten of the growing concerns him, causing his social concern, therefore,
targeted current research to identify patterns of parental care(mot
The synthesis, characterization and liquid crystalline properties of N4,N40-bis((1 H-benzo[d]imidazol-2- yl)methyl)-3,30-dimethyl-[1,10-biphenyl]-4,40-diamine and of their corresponding Mn(II), Fe(II), Ni (II), Cu(II), and Zn(II) complexes are described. The ligand and complexes have been characterized by elemental analysis, magnetic susceptibility measurements (meff), conductometric measurements and Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance (1H NMR), (13C-NMR) and UV–Vis spectroscopy. Spectral investigations suggested octahedral coordination geometrical arrangement for M(II) complexes. The phase transition temperatures were detected by differential scanning calorimetry (DSC) analysis and the phases are confirmed by op
... Show MoreReading roles as the third skill in the range of English as a Foreign Language (EFL) learning. Although the capability of reading in both academic and non-academic texts is assessed on standardized tests, few of oral interpretation of written language excludes images from estimating literary knowledge. This paper highlights strategies of reading comprehension and visual literacy. It aims to investigate either textual or visual reading in EFL can make an impact on students' comprehension. The effective use of visuals changes instructing reading comprehension recently.The imagery-text model can affect developing reading comprehension and enhancing intellectual thinking. The study hypothesizes that there is no relationship between reading and
... Show MoreIn a survey of the crabronid fauna of Iraq during June to October 2022; 9species belonging to the genus
The purpose of this paper to discriminate between the poetic poems of each poet depending on the characteristics and attribute of the Arabic letters. Four categories used for the Arabic letters, letters frequency have been included in a multidimensional contingency table and each dimension has two or more levels, then contingency coefficient calculated.
The paper sample consists of six poets from different historical ages, and each poet has five poems. The method was programmed using the MATLAB program, the efficiency of the proposed method is 53% for the whole sample, and between 90% and 95% for each poet's poems.
واحدة من أكثر مواد السيراميك الهيكلية الواعدة هي كربيد السيليكون(SiC) ، حيث له خصائص حرارية وكهروميكانيكية ممتازة. هذه الخصائص مفيدة ل CMC لتعزيز أداء المركب خاصة عند إضافات النانو المتكاملة. في هذا البحث, تم تصنيع مركب SiC من SiC بثلاثة تركيزات مع ZnO و Si. تم اختبار الخواص المغناطيسية لجميع المخاليط باستخدام مراقبة العينة الاهتزازية (VSM). تم تلبيد العينات الخضراء في فرن التلبيد عند 1600 درجة مئوية في بيئة النيتروجي
... Show MoreSaccharomyces Cerevisiae cells were immobilized in calcium alginate beads and activated charcoal for use in the
production of ethanol from batch fermentation of sugar beet waste. Treatment of the waste with NaOH to increase the
ability of lignocellulose material to hydrolysis by acid (2N H2SO4) to monosaccharide and disaccharide (mainly glucos).
The high reducing sugar concentration obtained was equal to 9.2gm/100ml (10Brix) after treatment. Fermentation
parameters, are (pH, glucose concentration (2.5-25 gm/100ml), immobilized agent concentration (2.5-25 gm/100ml)
were studied to find the optimum physiological condition. And the highest ethanol concentration obtained from the
fermentation in the presence of 20%(wt/v) ca
Colloidal crystals (opals) made of close-packed polymethylmethacrylate (PMMA) were fabricated and grown by Template-Directed methods to obtain porous materials with well-ordered periodicity and interconnected pore systems to manufacture photonic crystals. Opals were made from aqueous suspensions of monodisperse PMMA spheres with diameters between 280 and 415 nm. SEM confirmed the PMMA spheres crystallized uniformly in a face-centered cubic (FCC) array. Optical properties of synthesized pores PMMA were characterized by UV–Visible spectroscopy. It shows that the colloidal crystals possess pseudo photonic band gaps in the visible region. A combination of Bragg’s law of diffraction and Snell’s law of refraction were used to calculate t
... Show MoreStatistical studies are reported in this article for an active galactic nuclei sample of different type of active galaxies Seyferts 1, Seyferts 2, and Quasars. These sources have been selected from a Catalogue for bright X-ray galaxies. The name of this index is ROSAT Bright Source Catalogue (RBSC) and the NRAO VLA Sky Survey (NVSS). In this research, multi-wavelength observational bands Radio at 1.4 GHz, Optical at 4400 A0, and X-ray at energy 0.1-2.4 KeV have been adopted in this study. The behavior of flux density ratios has been studied , with respect to the absolute magnitude . Furthermore, the Seyfert1 and Seyfert 2 objects are combined in one group and the QSOs are collectest in another group. Also, it has been found that t
... Show MoreThis research delves into the role of satirical television programs in shaping the image of Iraqi politicians. The research problem is summarized in the main question: How does satire featured in television programs influence the portrayal of Iraqi politicians? This research adopts a descriptive approach and employs a survey methodology. The primary data collection tool is a questionnaire, complemented by observation and measurement techniques. The study draws upon the framework of cultural cultivation theory as a guiding theoretical foundation. A total of 430 questionnaires were disseminated among respondents who regularly watch satirical programs, selected through a multi-stage random sampling procedure.
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