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.
Witnessing human societies with the turn of the century atheist twenty huge revolution in information , the result of scientific and technological developments rapidly in space science and communications , and that made the whole world is like a small village not linked by road as it was in ancient times, through the rapid transportation as was the case a few years ago , thanks to the remote sensing devices that roam in space observant everything on the ground , that the information networks that overflowed the world a tremendous amount of information provided for each inhabitants of the earth , which made this information requirement for human life and human survival and well-being , as it has allowed that information to humans opportun
... Show MoreThe Beggar (1965) is a story of isolation and depression which is written by the Egyptian novelist Naguib Mahfouz who is considered the father of Arabic Literature in the modern era. Specifically, he refers in his great novel called The Beggar that the man unable to achieve psychological revival after Nasser’s revolution, the man sacrificed his own job and his family for a desire that increases his feelings of alienation and depression which leads him to an emotional outcry against the indifferent. The main aim of the study highlights the concept of existential dilemma as a philosophical problem and personality crisis by the protagonist of The Beggar novel, Omer Al-Hamzawi who had acc
... Show More
Psychological Counseling Services occupies a high position in the developed countries and that for its psychologist services for different sectors of the community members, and has been popularized until recently the wrong concept of the effect, that the psychological service is provided only to the owners of behavior is normal only, Vantage him neglect to provide psychological services a large segment of the community members who are in dire need of these services.
The counseling service is part of a global social movement seeking to emphasize the quality of life of the human and the emphasis on the value and dignity and the need to live a quiet lif
... Show MoreThe insects like other creatures in the wide world, and there are more than a million class and type of these objects, some of which human haunted since the old to the present day.
In this study highlight the insect bee addressing her life and behavior, and the novelty of her and wonders what mystified by the minds of men that her world is full of mysteries and surprises drew the attention of workers in the natural history of the study and scrutiny of methods and different characteristics of scientists as she gives more than it takes. It appeared that the Islamic heritage has singled out these insects with something of interest and precise detail, but that God Almighty made suras from the Koran carrying insect name two Sura
... Show MoreThis search modest deviation personal than to doubt that the event was not guilty by nature or offenders of evil in origin but is arictim of misfortune that makes him grow or live in the center of the corruption, even if he could be in the middle of the blessing of good and virtue and reform lived living righteousness and honor it was a useful member for himself and his community and must state and family community take hands mnhrfaite in order to prevent and provide then
The industries in Baghdad, the most important economic activities in the era albeit and Seljuk to the availability of manpower and resources which encourage the establishment of these industries in Baghdad.
These industries seam as simple crafts, but they may have influenced the nature of the social and economic life in the Baghdadi community during the foreign authority on Iraq and general in Baghdad in particular.
It is important to study that the social circumstances in Alexandria through Mamluk era specially social life in Egypt specially in Alexandria which had describe as it was show change in opposite with other sides of life
اسلوب الحوار في القرآن الكريم اسلوب حياة وفي حقيقة الامر يضم القرآن الكريم بين دفتيه حوارات كثير مابين الله عزوجل وخلقه وما بين الانبياء واقوامهم وما بين الانبياء والطواغيت ومابين المؤمنين والكفار وهكذا ، وبدء الخلق قام على حوار مابين الله عزوجل وآدم وما بين آدم وابليس وما بيا الله جل وعلا والملائكة .
Among the imams who honor the soil of Iraq by embracing their remains is Imam Al-Qasim Ibn al-Imam Musa Ibn Ja'far ibn Muhammad ibn Ali ibn al-Hussein ibn Ali ibn Ali ibn Abu Talib, Amir of the believers Al-Kadhim (may peace be upon him ), the mother of the sons and the mother of his brother Imam Ali ibn Musa al-Rida (may peace be upon him), buried in the Holy QOM (1)It is one of the doors of need for Shiite Muslims All the stories of imams are similar in terms of injustice
The goal of current research to know the according of scientific values in the curriculum of chemistry sixth - grade science To achieve this goal wasa to build aalistaofa scientifica values toa be included in the curriculum of chemistry sixth - grade science after seeing a group of literature and previous studies, the list presented to a group of arbitrators and specialists in educational and psychological sciences and methods of teaching science, and curricula and teaching methods , Arbitrators and specialists have expressed their views and comments on the tool, and that the list was formed in final form (9) values Head of scientific includes ( 35) sub - value, then the researcher analyzed the chemistry curriculum for sixth grade Scient
... Show More