Laser etching may be an alternative to acid etching of enamel and dentin. Several characteristics of irradiated dental hard tissues have been considered advantageous, microscopically rough surfaces without demineralization, open dentinal tubules without smear layer production and dentin surface sterilization. The aim of this study is to determine and compare histology the microleakage in class V cavity restored with a light cured composite after conditioning the samples(tooth surface) with 1-acid etching, 2-Q-switched Nd:YAG Laser etching and finally 3- acid and laser etching. Materials and methods: Twenty four non carious human extracted teeth were used in this study. The samples were equally grouped into four groups of six teeth each. A class V cavity was prepared. In group I, tooth surface was etched with a 37% phosphoric acid gel. In group II, the tooth surface was conditioned using a pulsed Nd:YAG Laser alone with a wavelength of 532 nm. The parameters were of pulse energy 60 mJ, pulse repetition rate 6Hz and energy density was 0.48 J/cm2. In group III, the tooth surface was treated with Nd: YAG Laser and then was etched with phosphoric acid. In group IV, the surface was treated with 37% phosphoric acid then irradiated with Nd: YAG Laser; with the same parameters and concentration mentioned in group I and II. The samples immersed in 1% basic fuschin dye to mimic the normal stains in oral cavity and the sections were examined by a stereomicroscope and the readings were scored. Results: The results showed that group IV, in which the surface was treated with 37% phosphoric acid and then irradiated with Nd: YAG Laser) recorded the least microleakage of the four groups, where group III, in which the tooth surface was treated with Nd: YAG Laser and then was etched with phosphoric acid)recorded reasonable results better than group I (group I tooth surface was etched with a 37% phosphoric acid gel) or group II , in which the tooth surface was conditioned using a pulsed Nd:YAG Laser alone) Conclusion: The use of Q-switched Nd:YAG laser in etching the tooth surface was so effective that it can be used in treating or conditioning the tooth surface to enhance bonding and the best parameters among the tested samples were pulse energy of 60mJ, pulse repetition rate of 6Hz and energy density 0.48 J/cm2.
حضيت القيادة باهتمام كبير من قبل الباحثين ودورها الإيجابي في التأثير على الموظفين ونجاح المنظمات، في الآونة الأخير بدأت الدراسات تركز على الجانب المظلم للقيادة وتأثيرها على التابعين وبيئة العمل، وقد تم تحديد القيادة السامة بأنها أخطر الأساليب القيادية التي تتسبب بتكاليف مادية ومعنوية على المنظمات بمختلف جوانبها، ان القيادة السامة تأثر على دوافع المرؤوسين وقدرتهم على انجاز المهام، ورغبتهم في الاستمرار في
... Show MoreThe research titles “Ammorrite tribes and their historical role in Mesopotamia and Levant” deals with tribe structure, nomination, political and cultural roles of these tribes in Mesopotamia and Levant, as it terminate Sumerian presence in Iraq and changed historical course and contributed in changing population landmarks and started new bright era, in addition to admitting new beliefs, gods and laws, beside ruling principles which became tribal, i.e., dynasties instead of Sumerian rulings based on religion belief.
Singled current study on the subject of shorthand in structure designs logos (Iraqi sports clubs model), as the current study Tdmt four chapters, was in the first chapter defines the research problem and its significance, as well as the aim of the research in the know shorthand formal in structure designs logos (Iraqi sports clubs model ), and identifies Find time limits: - slogans Iraqi sports clubs for the years (1956 - 1970), because it represented the years to include designs slogans official Iraqi sports clubs that have been elected in this period for the purpose of examining the reality of the design in the current search. And it represented the spatial limits: - the Republic of Iraq - Iraqi slogans designs sports
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Seemed reflections of cultural globalization are clear on the values of communities those values that preserve each community privacy, so that became members of these communities lack the ability to distinguish clearly between what is right and what is wrong and adoption of ideas and values imported from abroad, regardless of whether positive or negative. The aim of the research was to: - 1 - Detection of cultural globalization in the educational values for students kindergarten section. 2 - To identify the most prominent educational values (social, scientific, aesthetic, moral and spiritual) globalized culture. The current Aqtsralbges on: - Department of kindergarten students to study in the morning College for Girls, Baghdad University
... Show MoreThe research aimed at measuring the degree to which the accept their class environment in governmental & civil Kindergartens & it also aimed at knowing the differences between the dimensions of the measurement & the differences according to the kindergarten & class variables .
The researcher made a measurement for the class environment & it included five dimensions & the answering choices were three ( to a big extent , to some extent and no ) and after making sure that the measurement is usable , the researcher applied it on the sample which consisted of ( 212 )male & female children through the estimated answers of the teacher & the result was that there was an accep
... Show Moreالبنية الاقتصادية الاجتماعية للادارة الجديدة في الولايات المتحدة الامريكية
الفلسفة السياسية وفلاسفتها دراسة في فكر الفيلسوف ليو شتراوس
God bestowed upon the Imams of the Ahl al-Bayt (peace be upon them) knowledge and wisdom, in addition to give them virtue as long as it was not given to anyone from the worlds. knowledge have been enriched from them that cause pride.