Background: Crown preparation of vital teeth involve the removal of a sound tooth structure, and when enamel removed this lead to exposed dentin with an increase in the number of open dentinal tubules also the diameter of dentinal tubules will increase, furthermore lead to increase movement of fluids inside the tubules all that causes post preparation sensitivity. The aim of this study is to evaluate the effect of desensitizing by Er:Cr:YSGG laser on shear bond strength of prepared tooth and resin cement. Materials and methods: Thirty sound maxillary premolars, grouped into three groups(n=10). Group A is the control group, group B irradiated by Er:Cr:YSGG laser with (0.25 W, 20 Hz, 10%water and air), group C irradiated by Er:Cr:YSGG laser with (0.5 W, 20 Hz, 10% water and air). Results: SEM examination showed complete occlusion of opened dentinal tubules after laser irradiation of both groups that irradiated with laser. Statistical analysis showed significant increase in surface roughness in group B and C. SBS was significantly increase in group B with no significant increase in group C. Conclusion: Er:Cr:YSGG laser can occlude open dentinal tubules without and adverse effect on the retention of the restoration, on the contrary it increase bonding strength. And this increasing was significant in group B with (0.25W, 20 Hz, 10 % water and air). suggestion: so the parameters used in group B (0.25 W, 20Hz, 10 % water and air) is recommended for desensitizing prepared tooth and induce enhancement to the bonding strength of resin to tooth surface.
نظرية الشك بين استشراقية مرجليوث واستغرابية طه حسين
إن أهميـة بحثنـا تتضـح مـن خـلال التطـرق إلى دراسـة المـذهب العسـكري في حقبـة الاتحـاد السـوفيتي السـابق وإبـراز الجوانـب الرئيسـة المتعلقـة بفلسـفة المـذهب العسـكري السـوفيتي ومضـامينه الاستراتيجية مــن جانــب، وفلســفة المــذهب العســكري الروســي لمرحلــة مــا بعــد الحــرب البــاردة والتغـيرات المهمـة الـتي طـرأت عليـه، ممـا أفـرز لنـا بطبيعـة الحـال مضـامين مـذهب عسـكري روسـي جديــد قــد يتقــا
... Show MoreBridging the Gap between Graphemes and Phonemes in the Phonetic Transcription
José Echegaray, dramaturgo español, obtuvo premio Nóbel de literatura en (1904), político, orador, economista y dramaturgo. Con su obra "El gran Galeoto" en 1881, llegó a la cumbre de la popularidad.
Henrik Ibsen, dramaturgo noruega, creador del drama moderno, por sus obras realistas que abordan problemas psicológicos y sociales. Y a que fue el iniciador del teatro de tesis del teatro social. Ibsen, dramaturgo noruega, cuya obra influyó notablemente en el teatro europeo de finales del s. XIX y principios del XIX ; en gran parte en la obra de Echegaray, Galdós (1) y Benavente (2).
Los presentes autores empezaron sus producciones bajo el romanticismo que fue poco a poco añadiendo ideas del naturalismo y el realismo dramátic
Maintaining the manuscript, keep on national identity are a means to write history, so states seek to maintain, through a set of legal rules that criminalize the abuse as well as the development of national and international legal mechanisms. Algeria, was a state of the colony
This Research based on an empirical study and tested the hypothesis of transition effects on a sample of young people in Sharjah University and trying to identify a new form of Media which is based on the production of new types of habits and patterns and their cultural impact. Recently, New Media appeared to refer to new types of Communication using the Internet. It’s enormous in the exchange of Information. The new Media contains multiple forms, including the form in which users produce by them to refer the entry of a new area of Media in which exchange of roles between the Sender and the recipient.
This study is trying to identify a new form of Media Web used (Press online or only Press online, Digi
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Purpose – determine the impact of the promotional mix in achieving competitive advantage in industrial organizations.
Problem- indicated a clear deficiency in employing the dimensions of the marketing mix in ensuring a competitive advantage for the researched organization.
Design/methodology/approach – Al-Dora Refinery was selected as a field of application. The sample was chosen by an intentional sample of (143) individuals in the Human Resources departments. The questionnaire was adopted as a data acquisition tool that was prepared based on a set of ready-made standards after being subjected to a number of v
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Experienced economic environmentRadical changes at the end of the last century and the beginning of the present century, resulting in new concepts and expectations in all aspects of economic, political, social and even behavioral.Each of these concepts is the result of rapid developments in the intangible space. Competition is no longer limited to the mere possession of tangible material resources, but because of its link to knowledge and technology content and to the comprehensive quality standards and efficient and effective policies of States. With the increasing pace of growth and interdependence among the global economies, this resulted in the birth of a new economic system led by technological development and financial liberalizati
... Show MoreThe research dealt with two variables first in the field of human resources represented by the empowerment of workers and second in operations through improved process in the framework of standards Quality Award European containing nine basic criteria (Leadership, Strategy, partnerships and resources, the results of the individuals, the results of the customer, the results of the community), including human resources and operations has been selected and the Ministry of Industry and Minerals as a community to search , which covered most of the industrial sectors of Iraq through the selection of a single company of every industrial sector and thus became the research sample (6 ) industrial companies in addition to the C
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Oil sector is one of the most important sectors affecting the ecological balance, as activity contributes to the oil companies to influence their working environment, both during the oil exploration and extraction process or during transfer from one place to another process. We will try through this research put an environmental audit program proposal takes into account all the financial aspects, commitment and performance, according to the laws and regulations and agreements as well as relevant international standards, was based on research on the premise that the development of an environmental proposal auditing program that includes environmental controls on oil industry phases which helps reduce or minimize environmental pollutants B
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