ABSRTACT Background: Soft liner material is become important in dental prosthetic treatment. They are applied to the surface of the dentures to achieve more equal force distribution , reduce localized pressure and improve denture retention by engaging undercut . So the aim of the study is to evaluate the effect of different surface treatment by air-abrasion AL2O3 and laser treatment with CO2 laser on improving the shear bond strength of the denture liner to acrylic denture base material . Materials and methods: the 30 specimens of heat cured acrylic denture base material (high Impact acrylic )and heat cured soft liner (Vertex ,Nether Lands )were prepared for this study .They were designed and divided according to type of the surface treatment 10 specimens for each group and as follows :Group I without any treatment (control group ), Group II was treated with air-abrasion (AL2O3). While group III was treated with CO2 laser which has continuous pulses with wave length(10.6) micro-meter for (15) seconds . Results: The results revealed that lowest mean values in shear bond strength the specimens treated with AL2O3 (0.498 N/mm2)and control group (0.569 N/mm2)and the highest mean values for the specimens treated with CO2 laser (0.648 N/mm2) . Conclusion: within the limitation of this study ,CO2 laser surface treatment of the heat cure acrylic denture resin with soft liner material resulted in highly significantly increased in shear bond strength values than control and AL2O3 .
In this work a novel drug delivery system through modification of poly acrylic acid with Methionine as a spacer between the poly acrylic acid which was converted to its acyl chloride and reacted with Methionine as spacer unit which has been reacted with Ampicillin drug. In vitro drug release study had been conducted successfully in basic medium in pH 7.4 and acidic medium in pH 1.1 at 37?. Due to many problems associated with drug release and, this modification could decrease the side effect of drug. The prepared prodrug polymer was characterized by spectra method [FTIR and 1H?NMR]. Physical properties and intrinsic viscosity of drug polymer were determined. The good results were obtained in the presence of spacer unit with compar
... Show MoreThe Cu2SiO3 composite has been prepared from the binary compounds (Cu2O, and SiO2) with high purity by solid state reaction. The Cu2SiO3 thin films were deposited at room temperature on glass and Si substrates with thickness 400 nm by pulsed laser deposition method. X-ray analysis showed that the powder of Cu2SiO3 has a polycrystalline structure with monoclinic phase and preferred orientation along (111) direction at 2θ around 38.670o which related to CuO phase. While as deposited and annealed Cu2SiO3 films have amorphous structure. The morphological study revealed that the grains have granular and elliptical shape, with average diameter of 163.63 nm. The electrical properties which represent Hall effect were investigated. Hall coeffici
... Show MoreAs regional development, as a matter of course, poses a number of systemic, scientific and political problems. While the issue of development is primarily at the national level to the limits of World War II in the industrialized world and to the 1960s borders in most Third World countries, the increasing awareness of regional disparities has led to the regional issue Were taken into consideration in the early 1960s and 1970s in most industrialized and developing countries alike. The local issue was only introduced in the early 1980s. The awareness of regional disparities and the fact that the regions do not have the same potential and that some regions have the resources to enable them to develop, grow and develop, unlike other r
... Show MoreThis research investigates the subject of the impact of wars (as a manifestation of crisis) on architecture, and the extent of continuing wars physical and moral results of wars, even after the end of the cause of the crisis. The impact of different rebuilding which exposed to the effects of the war seems different in crisis regions.
The problem of research is about the uncertainty of the impact of the way chooses for reconstructing the buildings after wars in the continuity of the crisis of war. The goals of this research are to clarify the influence of methods of reconstruction of buildings in a city chosen which is Beirut, on the continuation of the war crisis with the argument of demolishing and rebuilding newly or keeping tr
... Show MoreTHE PROBLEM OF TRANSLATING METAPHOR IN AN ARTISTIC TEXT (ON THE MATERIAL OF RUSSIAN AND ARABIC LANGUAGES)
The research tackles the nature of relationship between the Orthodox Church and the state in the Russian Federation. At the beginning of the nineties of the last century, the church had been performed a different role in its relationship with the state, and it had an effect over the internal and foreign policies for the Russian Federation. In political history of Russia, the church’s existence became an evident too much in comparing with the previous historical period, starting with the educational and political system, whether through a symbolic participating roles as what happened in the inauguration ceremony to take over responsibility of the head of state or taking actual roles such as influencing on the process of holding elections d
... Show MoreThe internationalization of the Libyan crisis and its accompanying militarization of the conflict have played a vital role in hindering to reach a comprehensive political settlement solution in Libya. The increasing international greediness in the Libyan energy resources and the geopolitical importance of the Libyan State led to the involvement of many international and regional powers in this crisis and transformed the Libyan crisis into “proxy war”. Moreover, the Turkish direct military intervention in the Libyan crisis is considered as one of the main constraints facing the international and regional efforts to settle the Libyan crisis as a result of the Turkish insistence on its military existence in Libya to preserve i
... Show MoreBackground: Surface treatment of machined dental zirconia for enhancement of the adhesion to resin cement, using Er,Cr:YSGG Laser. Materials and Methods: Total number of 42 zirconia disc specimens (9 mm diameter, and 2 mm height) was sintered according to the manufacturer instruction. They are divided into six groups, each group of seven samples. Laser groups (Experiment parameters) were depend on laser total irradiation time, pulse duration, and power. Group (A): 20 sec., 60 µs pulse duration. Group (B): 30 sec., 60 µs pulse duration. Group (C): 40 sec., 60 µs pulse duration. Group (D): 20 sec., 700 µs pulse duration. Group (E): 30 sec., 700 µs pulse duration, with different powers used (1, 1
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