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.
لقد اعتبر انسان وادي الرافدين قديماً، الكون عبارة عن دولة كونية، وكل مافيه - اي الكون كان يعد عبارة عن ذوات فردية، فكل حي وجماد وفكرة مجردة وكل حجر وكل شجرة وكل خاطر يتمتع بارادة ذاتية وشخصية خاصة، لقد تمثل الكون في ذهن الانسان بهيئة واحدة الا وهي نظام من الارادات فالكون ككل منسق انما هو مجتمع، أو دولة فكانت هذه الدولة الكونية تضم إلى جانب الشخصيات الفعالة في هيئة الحكم اعضاء لم يكن لهم نفوذ في السياسة ولا دور ل
... Show Moreأصل التفاوت في الاتجاهات السياسية بين الناس
It is not available for us to go back in time and see plays old and it plays giants tragedy ancient Greek (Aeschylus, Sofokls, and yourbedes) through the eyes of a generation ago, and if we were able to go back to Ntegathm play it is certain that we will not taste or Nstassig for much of what we see from these offers will not afford the traditional religious rituals, which was accompanied also dance and music in the style of ancient Greek play was representing a large part of the theater see manifestations Can our eyes and ears we twentieth century audience to accept those appearances, and it was then?
Inevitably it will look like a museum bycollection not only. So we find ourselves in the light of the foregoing forced When you do rem
The new media scene reveals that the unprecedented overlap of a number of technical, economic, and political factors has made the new media a very complicated issue; and the focus of specialized and public debates about its impact on traditional means of communication and forms of social media and social relations. Then, the same scene discloses the reality of the relationship between the new and the traditional. These are the axes that will be will be discussed in this study.
The typographic accomplishment is the most important means of cognitive communication and carries a message from the sender to the recipient which serves a certain objective functionally, economically and advertisingly.
The design of typographic accomplishment depends on two different techniques, the first is manual, which depends on the skill, training and individual achievement of the designer and his ability to design and produce typographic accomplishment with manual skill effects. The second one is the contemporary digitization which is represented by computers, programs and printers attached to them. The problem of the current resear
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Humans have considerations of gender male and female, and many of them have preferential male versus female, and became such considerations solid in the minds of some of the intellectuals, public and most of the people; as a fact for granted, and that's what get them to prefer of boys over females.
The research deals with an analytical approach between new media and traditional one in the light of the changes imposed by technology, which has been able to change a number of common concepts in the field of communication and media. The researcher tries to find an analytical explanation of the relationship between technology by being an influential factor in building the information society, which is the basis of new media, and the technical output that influenced the forms of social relations and linguistic construction as a human communication tool. The research deals with an analytical approach between new media and traditional one in the light of the changes imposed by technology, which has been able to change a number of comm
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This research was from an introduction, three topics and a conclusion, as follows:
The first topic: the concept of Islamic banks and their emergence and development, which includes three demands are:
The first requirement: the concept of Islamic banks and types, and there are two requirements:
* Definition of Islamic banks language and idiom.
* Types of Islamic banks.
The second requirement: the emergence and development of Islamic banks.
Third requirement: the importance of Islamic banks and their objectives.
We learned about the concept of banks and their origins and how they developed and what are the most important types of Islamic banks
The second topic: Formulas and sources of financing in Islamic banks and
لظهور كثير من الاراء التفسيرية والنقدية والتي تباينت في كثير من الاحيان وبخاصة من المفسرين والمستشرقين لاختلاف المشارب الفكرية لكلا الفريقين وهو ما تطلب تاصيلا لعملية النقد والمقارنة بين المنهجين