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.
Islamic manuscripts are considered an identity for the civilizational, cognitive and cultural development of nations and the Islamic world as a whole, and to identify this identity, the closing statement usually written at the end of the manuscript helps us with this, meaning that the closing entries serve as the identity document of the manuscript
As the reservoir conditions are in continuous changing during its life, well production rateand its performance will change and it needs to re-model according to the current situationsand to keep the production rate as high as possible.Well productivity is affected by changing in reservoir pressure, water cut, tubing size andwellhead pressure. For electrical submersible pump (ESP), it will also affected by numberof stages and operating frequency.In general, the production rate increases when reservoir pressure increases and/or water cutdecreases. Also the flow rate increase when tubing size increases and/or wellhead pressuredecreases. For ESP well, production rate increases when number of stages is increasedand/or pump frequency is
... Show Moreأدى التغير السريع في البيئة الخارجية للمنظمة إلى ظهور حالة من التنافس الشديد مما زاد تخوف الشركات من فقدان الحصة السوقية والخسارة . مما حدا بالمنظمات إلى الاهتمام بوجود مدير يحمل صفات وخصائص قيادية لما فيه من ميزات في تنظيم الإنتاج ومقابلة الطلب وتقليل التكاليف وتطوير الأداء للحصول على ميزة تنافسية تحافظ او تزيد من حصتها السوقية وإرباحها .
تسعى الدراسة الى تحديد عدد من الاهداف كان اهمها معرفة الع
... Show MoreType 2 daibetes mellitus (T2DM) is a global concern boosted by both population growth and ageing, the majority of affected people are aged between (40- 59 year). The objective of this research was to estimate the impact of age and gender on glycaemic control parameters: Fasting blood glucose (FBC), glycated hemoglobin (HbA1C), insulin, insulin resistance (IR) and insulin sensitivity (IS), renal function parameters: urea, creatinine and oxidative stress parameters: total antioxidant capacity (TAC) and reactive oxygen species (ROS). Eighty-one random samples of T2DM patients (35 men and 46 women) were included in this study, their average age was 52.75±9.63 year. Current study found that FBG, HbA1C and IR were highly significant (P<0.01) inc
... Show MoreThe topic of the research on the Observatory of the Walls on Jurisprudential Matters in the Hanafi Fiqh, by Imam San’a Allah bin Ali bin Khalil Al-Ala’iyya Wai al-Naqshbandi, al-Rumi, who died in 1137 AH, which includes seven chapters, the first section of it concerning division and related matters, and the second section in the adaptation It is the apportionment of benefits in common objects, the third section, which pertains to lines, surfaces, and bodies, the fourth section, which concerns the inclined wall and certification, and the fifth section, which concerns the provisions of the walls and its claims, and the sixth section, which concerns the door of roads and doors, the opening of the skylight, the sails of the wing, the can
... Show MoreThis study utilized low-cost agricultural waste (molasses production waste powder) to extract copper ions from aqueous solutions. The present investigation explored a range of factors that influence the adsorption process, including temperature, pH, ionic strength, contact time, quantity of adsorbent, and particle size. Spectrophotometric analysis was used to determine the solution's absorbance both before and after the adsorption procedure. The Langmuir and Freundlich adsorption models were used to match the equilibrium data. The Freundlich model was determined to be the best isotherm model using the linear regression coefficient R2=0.9868. Thermodynamic parameters, including enthalpy, entropy, and Gibbs free energy, were calculate
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