It is found that hypersensitive teeth have a larger number and wider patent tubules than those of non-sensitive teeth. Objective: The aim of this study is to compare between the effects of diode laser at different power densities, with and without sodium fluoride on the sealing of exposed dentinal tubules and dentin permeability. Materials and methods: 118 teeth were used. Samples were divided into three major groups. The first consisted of 100 teeth used for permeability test. The second consisted of 16 teeth for measuring external surface temperature elevation while irradiation. The third, in turn, consisted of one pair of teeth observed under SEM for dentine surface morphology analysis. Results: For dentin permeability measurement, the results revealed a highly significant difference between the control group and 2, 3 W with varnish groups. For the external surface temperature elevation, the results revealed that temperature rise, for both laser alone and with varnish groups, was between (67-97.9 ∘C) at 1.6, 2 W. SEM analysis revealed that approximately optimum sealing of tubules occurred in 2W with the varnish group. Conclusions: The combined application of 940 nm diode laser at 2W with 809.7 W/cm² power densities, with sodium fluoride white varnish show a significant improvement in their effects on dentin permeability reduction as compared to each treatment alone.
على الرغم من إن الابداع والمبدعين وخصائصهم العقلية والشخصية تعد من المفاهيم المهمة والشائعة في الحياة بمجالاتها كافة، ففي الوقت الذي نجد فيه العديد من الدراسات والمقالات العربية والاجنبية التي تناولته بشكل او باخر، لكنها جميعها اعتمدت على المقياس الخاص بالتفكير الابداعي لمؤسسه الاول تورانس منذ عام (1967)، متجاهلة التغيير والتطور المعلوماتي ولا سيما في الانترنيت والحاسوب وما افرزه هذا من مفردات شاعت وتداول
... Show Moreاستأثرت ظاهرة هجرة العقول او (الكفاءات العلمية) خلال العقدين الاخيرين باهتمام البلدان المتقدمة والنامية على حد سواء ، وذلك نسبة لاثارها السلبية والايجابية ، على الواقع الاجتماعي والتنموي في الدول المرسلة والمستقبلة ، وزاد الاهتمام بهذه الظاهرة في البلدان النامية لما ينجم عن هجرة العقول من خسارة البلدان المرسلة للموارد البشرية العالية التاهيل ، واللازمة لتحقيق النمو الاقتصادي ذ
... Show MoreIn this paper, experimental study has been done for temperature distribution in space conditioned with Ventilation Hollow Core Slab (TermoDeck) system. The experiments were carried out on a model room with dimensions of (1m 1.2m 1m) that was built according to a suitable scale factor of (1/4). The temperature distributions was measured by 59 thermocouples fixed in several locations in the test room. Two cases were considered in this work, the first one during unoccupied period at night time (without external load) and the other at day period with external load of 800W/m2 according to solar heat gain calculations during summer season in Iraq. All results confirm the use of TermoDeck system for ventilation and cooling/heat
... Show MoreSome great families in England had competed for the sake of getting authority and power in England.
This competition turned to be a bloody civil war which extended till 1455 and ended with the victory of Henry Tudor whose judgment in England started from 28th of August 1458, consequently a new dynast which is known as (the Tudor)has established
يعد الدين من أكثر المتغيرات تأثيرا في سلوك البشر بصورة عامة ، وفي شخصياتهم وصحتهم النفسية بصورة خاصة .
ولأحداث الحياة والأزمات والشدائد تأثيرها الكبير في هذا المتغير وفي مدى تمسك الناس بقيمهم الدينية .
وفي العراق ، لا تخفى علينا المآسي والأزمات والشدائد التي مر ويمر بها البلد مما قد يزعزع ثقة الناس بمعتقداتهم وقيمهم ، ومن جانب آخر فان دخول المحت
... Show Moreاثر بديع الزمان سعيد النورسي على الفكر الاسلامي المعاصر في تركيا
It is axiomatical that the narrative prospective is profoundly significant to the writer who intends to commence his sketch of projected novel. It is the pillar of comprehensive absorbing as the writer should commit himself to circular his own concepts to the reader of his narrative characters.
The dilemma of plot-perception is a twofold aspect; partly offers the question: what is the authors stand in regard to his characters? And: what is the aim of this theme? These correlative questions are inseparable since the reader who wishes
... Show MoreAn integrated lithofacies and mineralogical assemblage was used to describe a depositional model and sequence stratigraphic framework of the Maastrichtian–Danian succession in the Western Desert of Iraq and eastern Jordan. Fifteen lithofacies types were grouped into three associations recognized in a distally steepened ramp characterized by an apparent, distinct increase in a gradient paleobathymetric deepening westward. The clay and nonclay minerals are dominated by smectite and palygorskite, with trace amounts of kaolinite, sepiolite, illite and chlorite. Meanwhile, quartz, calcite, dolomite, opal CT (Cristobalite - Tridymite), and apatite are the main nonclay minerals. The widely dominated smectite in the Western Phosphatic Basin of Ir
... Show More
(15)
(12)
This study aims to identify both the importance of using (LinkedIn) and its drawbacks for researchers and specialists in the field of information and knowledge technologies. The study relied mainly on the statistical method (analytical method) from the collection of data tools (questionnaire) that was distributed electronically (Google Forms) to the sample community of (55) instructors. The feedback received illustrates that (46) instructors among those who participated in the questionnaire subscribed to (LinkedIn) and the rest did not. Their data was analyzed statistically, and the general arithmetic mean and the hypothetical mean was extracted for them to achieve the objectives of the study and prove their hypotheses. The site positively
... Show MoreShe noted most of the results of research conducted on the use of computers and the Internet in the areas of administrative, economic, agricultural and educational to a significant improvement in learning outcomes of these groups in the development of mechanisms of action, has increased rates of computer use and applications in various spheres of life at very fast pace so that the computer and the Internet is a vital part of any activity, whether administrative or research or the media, hence it can be said that the use of computers and the Internet in the management of public relations activities in any organization can accelerate the pace of echo positive goals and purposes of public relations, this study comes to looking at us
... Show More