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.
Argumentation in the era of Andalusia poetry Denominate on the orbital roses and narcissus to Abu Bakr bin Gothic model research deals with the subject of Argumentation and employment in Andalusia Poetry has been studied in two sections display in the first reasons of self- Argumentation included human relationships
تفضيل السيولة - تضخم جانب الطلب - الاستقرار النقدي - معدل التضخم
فعالية الوثب العالي تمتاز بالتكرار والممارسة لمراحل التسلسل الحركي بالتكرارات الصحيحة المصحوبة بالتغذية الراجعة من اجل الوصول إلى اداء افضل, ومن خلال عمل الباحثتان كونها تدريسية لمادة الساحة والميدان لاحظت ضعفا في مستوى الأداء الفني عند الطالبات في ضبط مراحل التسلسل الحركي الكامل لفعالية الوثب العالي ، لذا ارتأت الباحثتان اعداد تمرينات خاصة باستخدام أساليب التنافس حمل المتعلم على مضاعفة جهده لينافس ذاته
... Show Moreأن أزدياد أعداد الطلبة في معظم دول العالم ، والتوسع في التعليم العالي ، أدى الى أستيعاب أعداد كبيرة في المؤسسات التعليمية من حملة الشهادات العليا الماجستير خاصة والدكتوراه ، وأن برامج الدراسات العليا وضعت لأعداد باحثين مختصين في مجالات عدة منها التدريس وما يتطلبه من مهارات مختلفة ، فأن قسماً منهم ليست لديه المعرفة النظرية والتطبيق العملي والمهارات اللازمة لأستخدام طرائق التدريس والتقنيات التربوية أث
... Show MoreThe present study aims at knowing the effect of Woods' model in correcting the geographical missUnderstanding for first stage students. In order to realize the objective of this study, the researcher used an experimental design with partial adjustment which is experimental group with another control group. The research is confined to the first four chapters of the boon of the principles of geography to be studied for the first stage in the academic year (2010/2011) in Iraq. The researcher chooses purposely the chose a staple form the first stage in Hay Al-Jama'a School for boys, in order to apply the experiment. The total number of the sample was (60) students who were distributed randomly as (30)per group. The researcher matched two gro
... Show MorePeaceful coexistence is not seen as a new topic of secretions of modern civilization, a requirement to solve the problems of our era or one of the indications of urgent immediate needs, rather, tolerance is considered basis for building a state. Therefore, we can touch on the principles and basics of tolerance in the Holy Qur’an, the speeches of the Messenger (may God bless him and grant him peace) and his hadiths, and the principle of brotherhood that he established
A financial analysis tool such as financial rations concentrates on explanation of financial statement and using them in the evaluation of company profiles and fixing taxable profits, by analyzing final calculation, explaining their results and studying relationships between a group of financial lists 'elements in a specific period and the trend of their relationships in percentage from so, financial analysis is considered on important instrument for tax analytical test procedures through studying and evaluating financial data in order to get proper information which is needed to make sure of credibility and reliability of statements submitted by the taxpayer and the satisfaction of the tax analyzer in the credibility of these statements
... Show MoreIslamic Culture face many challenges Such as، Secularism، westrenism، globalism and Colonialism under current attempts For western States and united states of America to dominate on world and Confront all her Opponent Polaris it be clear when U. S. A. Occupied Afghanistan and Iraq and Threatened many Arabic and Islamic States