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.
Abstract
The problem with the search at the reduction of adoption of new products, as there are three hypotheses of research have been formulated , the first one is no significant correlation between the religious and differences to customers and adopt new products, and This Study Aimed To Investigate The Relationship Between Religious differences for customers And New Products Adoption, Applied On Arab Mall Commercial Customers/ Egypt, an Analytical Model Is Developed As Guideline To Test The The Relationship Between Religious differences for customers And New Products Adoption, Aquantative Method With Deductive Approach Were Chosen In This Research . In Order To Collect Primary Data, A questionnaire Is
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يناقش البحث ابعاد العلاقات العراقية الايرانية قبل عام 2003 وما بعدها واهم المتغيرات الداخلية ( السياسية ، الاقتصادية ، الديموغرافية ، الامنية ) والخارجية ( الاقليمة ، الدولية المؤثرة عليها وافاقها المستقبلية
Science is linked to each other bonds assets, branches and even close to each other; to become a link of this type of patterns of scientific integration, and perhaps the most prominent science that saw the overlap and interdependence of science and jurisprudence and its origins, and this interdependence did not stop at the epistemological foundations of knowledge; To the branches, methods of extraction, and diligence to extend to the terminology; to find similar terms in both flags; to become those terms similar in the word and meaning and even the end, but we do not lack terms similar in pronunciation and differing in meaning; and this difference is imposed by the specificity of each science and what M E; however, approached many terms
... Show Moreأسلوب العطف: دراسة مقارنة بين اللغة العربية والاسبانية
تشهد ظاهرة عمالة الأطفال انتشارًا عالميًا واسعًا، حيث يعمل حوالي 250 مليون طفل في مختلف أنحاء العالم، من بينهم 150 مليونًا في أعمال خطرة، وأكثر من مليون طفل يتعرضون للاتجار بالبشر. ورغم أن هذه الظاهرة شائعة في الدول النامية والفقيرة، إلا أنها لا تقتصر عليها، بل تمتد إلى الدول الصناعية المتقدمة بنسب متفاوتة حسب طبيعة المجتمعات. ونظرًا لتعقيداتها وآثارها السلبية، حظيت هذه المشكلة باهتمام متزايد خلال العقود الأخ
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Interested in current research examining the concept of synthesis in contemporary ceramics, he studied the synthesis as a concept to achieve technical and aesthetic innovation.
The study comes in four axes. The first axis to ensure the general framework for research, containing the problem, which is to ask the following: Is the concept of synthesis role in enriching the contemporary ceramic done? The importance of research and study are needed in addition provide knowledge in the field of contemporary art
بعد الانحرافات التي شابت تنفيذ المسؤولية عن الحماية في ليبيا عام 2011، دعت البرازيل الى اتباع التسلسل في تنفيذ الركائز الثلاث للمسؤولية عن الحماية عند معالجة الازمات الانسانية ذات الصلة بجرائم الحرب والجرائم ضد الانسانية وجريمة الابادة الجماعية وجريمة التطهير العرقي، في حين دعا الامين العام للامم المتحدة في العديد من تقاريره السنوية بشأن المسؤولية عن الحماية بانه لاينبغي التقيد بالتسلسل واعتبر ان الركائز ا
... Show MoreThe problem of constant and change values is one of the important problems that the philosophy thought had faced as the religious and social studies had taken it as it considers as one of the most dangerous which touch the basic . the research deals with the effect of change value of new Iraqi situation to be as an attempt , as participation or an excitement that can be occupied a space through the area of questions on the fix and change of moral values shed light on the economical ,social and political events that the Iraqi society passes through them .it is part of interests that becomes importance to everyone through the light of moral change Which is arbitrary to the life of the individual .It is not possible to rebuild the society o
... Show MoreThe penalized least square method is a popular method to deal with high dimensional data ,where the number of explanatory variables is large than the sample size . The properties of penalized least square method are given high prediction accuracy and making estimation and variables selection
At once. The penalized least square method gives a sparse model ,that meaning a model with small variables so that can be interpreted easily .The penalized least square is not robust ,that means very sensitive to the presence of outlying observation , to deal with this problem, we can used a robust loss function to get the robust penalized least square method ,and get robust penalized estimator and
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