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.
بدأ الاهتمام بموضوع الرضاء الوظيفي في مجال العلوم الإدارية خلال العشرينات من القرن الماضي، من خلال مدرسة العلاقات الإنسانية على يد (التون مايو (Elton Mayo والتي تؤكد فيه على الاهتمام بالعنصر البشري، والذي بدوره يؤثر تأثيراً كبير على الإنتاج، ومن ثم فان زيادة الإنتاج تتحقق من خلال فهم طبيعة الإفراد،
The magazine is one of the print media , which represents an important gateway to the wider world , due for its intellectual and cultural fun for the recipient affecting the everyday needs him in various directions . The cover of the magazine is the owner of appearance and impact of the first look the magazine , including the magnitude of the value of the functional and aesthetic pay the reader to the acquisition, as it seeks designed to attract the receiver and achieve better grades optical communication enabled this diversity vocabulary construction for the cover of the magazine and consistent with the idea of design .Ensure Current search four chapters , first chapter of which , the research problem and was questioning following what
... Show More
This paper deals with aesthetic and a sitting position in contemporary Iraqi sculpture and studied this situation, an analytical study to reveal how to employ them in aesthetically pleasing work of art has been research in a sitting position to a lack of technical library for such research, this study includes four chaptersChapter I contains the research problem and its importance in terms of the released address and its objectives in the detection of this situation, how to employ the HDL research is to detect how the aesthetic of the Employment sit position and limits Find business is bronze and stone-dimensional exclusively carried out from 2000 to 2009 AD.Chapter II included the Framework theory and previous studies and with three Inv
... Show More
We must live in an era dominated by the call for equality between men and women, in which the voices of advocates of gender integration were heard. After women opened their doors to compete with their brother, Knowledge, and culture in the various forms of life, language as a science of the time and knowledge of the other had to match this reality and express the most accurate expression of this task
يقوم الخطأ المضمر على فكرة مبناها استنتاج الخطأ من وقوع الضرر، منشئاً بذلك قرينة قانونية بسيطة للمدعي (المضرور) تعفيه من اثبات خطأ المدعى عليه (المسؤول)، وهذا الافتراض في الاساس فكرة قضائية وجدت لمساعدة المضرور في الحصول على التعويض في حالة عدم تمكنه من تحديد خطأ المسؤول ، الا انه افتراضٌ قابلٌ لإثبات العكس من خلال نفي اي خطأ صادر عن المدعى عليه ، ويمكن نفيه ايضاً بإثبات انقطاع السببية بين الخطأ المضمر والضرر
... Show Moreاثر التواجد العسكري الامريكي على النظام السياسي في العراق
Manipulation is a discursive concept which plays a key role in political discourse by which politicians can impose some impact on their recipients through using linguistic features, most prominent of which are personal pronouns (Van Dijk, 1995). The aim of this study is to investigate how politicians utilize the personal pronouns, namely; We and I and their possessive forms as a tool of manipulating the audience's mind based on Van Dijk's "ideological square" which shows positive-self representation and negative-other representation (Van Dijk,1998:p.69). To this end, American President Donald Trump's 2020 State of the Union speech was chosen to be the data of analysis. Only (8)
... Show More
(1)
Although the majority of trends confirm the design aspects of the performance, functional and aesthetic design of the product. However, the attention was more focused on the nature of the plastic for those results, it is through the appearance of formal and guaranteed career such as designing Achieved adopt us the extent of the impact Relations Association between the elements and principles of design to achieve complementarity in the completed design of aesthetic and functional significance expressive and symbolic and in doing so has introduced a lot of new concepts for the arrangement and organization, coordination and functional classification of the unfinished design gave way to show diversity trends in the design of industrial produ
... Show More
Address the current research study " Symbol Significances in Fakhir Mohammad Paintings " in an attempt to detect signs of the icon in the artist's fee . The research contains four chapters The first chapter of which the methodological framework for the search starting with the problem of the specific research and asking the following: Maaltold semantic code in fees Luxury Muhammad? As well as displaying the importance of research and the need for it and in order to search through ( you know the implications of the code in the fee Luxury Muhammad) and for the period of ( 1980-2010 ) in his works of art as well as identifying the search terms . In the second chapter , such as the theoretical framework , and contained three sections focus o
... Show More