Background: The marginal adaptation has a key role in the success and longevity of the fixed dental restoration, which is affected by the impression and the fabrication techniques .The objective of this in vitro study was to evaluate and compare the marginal fitness of lithium disilicate crowns using two different digital impression techniques (direct and indirect techniques) and two different fabrication techniques (CAD/CAM and Press techniques). Materials and Methods: Thirty two sound upper first premolar teeth of comparable size extracted for orthodontic reason were selected in this study .Standardized preparation of all teeth samples were carried out with modified dental surveyor to receive all ceramic crown restoration with 1 mm deep chamfer finishing line, 4 mm axial length and 6 degree convergence angle. Half of the teeth were duplicated and poured in type IV dental stone to have sixteen dies and then these dies and the remaining teeth divided in to two groups according to the type of digital impression techniques (n=16) as follow: Group A: Indirect digital impression technique scanned by inEos X5 camera; Group B: Direct digital impression technique scanned by CEREC AC Omnicam camera. Each group was subdivided according to the technique of fabrication into two subgroups (n=8): Press technique using IPS e-max press (A1, B1); CAD/CAM technique using IPS e-max CAD (A2, B2).Marginal gaps were evaluated on the prepared teeth at four defined points on each aspect using digital microscope at a magnification of (280X). One way ANOVA and LSD tests were used to identify and localize the source of difference among the groups. Results: The results showed that indirect digital impression with IPS e-max CAD/CAM group A2 revealed the poorest marginal integrity with (55.93 μm ± 3.300). Group B2 and group A1 were next in line with(44.49 μm ± 6.840 and 37.74 μm± 5.433) respectively, while in the first group of restorations, the result of 29.9 μm ± 5.534 obtained with direct digital impression with pressable ceramic was clearly better. Conclusions: All the tested digital impression techniques showed clinically acceptable accuracy and intraoral scanning with pressable ceramic significantly enhanced the marginal fit
This research deals with the color bias and its effect on maids in Mississippi in Kathryn Stockett''s (2003) The Help. The ill-treatment and negligence of Afro-American maids received from the white women who employed them in Mississippi that must have affected directly or indirectly on their personality and may eventually lead to suffering. They live in an atmosphere of struggle to free themselves from the complicated relationships between black and white. Afro-American maids pledged to liberate themselves from social oppression by protesting through writing a book which chronicles their stories in slave masters’ homes to make their presence felt as human being equal to their white masters.
The mechanical function of the heart is governed by the contractile properties of the cells, the mechanical stiffness of the muscle and connective tissue, and pressure and volume loading conditions on the organ. Although ventricular pressures and volumes are available for assessing the global pumping performance of the heart, the distribution of stress and strain that characterize regional ventricular function and change in cell biology must be known. The mechanics of the equatorial region of the left, ventricle was modeled by a thick-walled cylinder. The tangential (circumferential) stress, radial stress and longitudinal stress in the wall of the heart have been calculated. There are also significant torsional shear in the wall during b
... Show Moreمن أجل فهم دور سلطنة عُمان في المفاوضات الإقليمية والوساطة وحل النزاعات يجب تقدير سياستها الخارجية، والتي سيتم تقييمها من أجل فهم كيفية نشأتها وتشكلها وأثر ذلك على مواقفها السياسية طوال سنوات حكم السلطان الراحل قابوس بن سعيد. وتقع عُمان في منطقة مضطربة، وقد طُلب منها في عدة مناسبات أن تعمل كمفاوض أو وسيط في الصراعات الإقليمية. سيبحث هذا البحث في كيفية قيام السلطنة بالوساطة الدولية، خاصة في الصراع الأمريكي
... Show MoreThe easternmost Mediterranean Basin is a candidate to be one of the most important hydrocarbon regions in the world, especially after significant gas discoveries in Levantine Basin in 2009. Offshore Syria is one of the easternmost Mediterranean areas which is still an unexplored virgin area. The seismic interpretation results of the study area showed encouraging evidences of considerable hydrocarbon accumulations within different sedimentary successions, which are Direct Hydrocarbon Indicators (DHIs). Indicators such as reflectivity anomalies (flat spots and dim spots) and polarity reversal were found within significant structural highs of Tertiary or/Late Cretaceous and Early Jurassic successions. Also, gas chim
... Show MoreOver last decade, rapid growth in economic and population accompanied with depletion of the energy resources lead to serious impacts on environment and humanity. This development coupled with active constructions, which in some examples ignore the impact on the environment and human activities. Therefore, principle of sustainability has required in order to reducing this negative impact on the environment and the humanity.In developing countries, it seems that there is a huge gap between the current construction practices and sustainable principle, which need more attention to clarify and define the problems in order to find suitable solutions before it comes more difficult and expensive. The study aims to choose one of the develo
Any research focusing on the teaching-learning process must focus on the learner, by mobilizing the various devices to facilitate and optimize learning. In this context, we introduce the integration of educational technologies into a personal learning environment (PLE). The PLE has significant potential for learning; namely self-construction and self-management of knowledge. According to Attwel (2007b), the development and improvement of PLE will lead to drastic changes in the way we use educational technology, as well as in the organization and ethics of education. With the present contribution, we try to modelize the PLE of students within institutions of higher education in Morocco. Based on data from a questionnaire put online using
... Show MoreBetween the duality of sound and image, the completeness of the actor’s personality at the director comes to announce the birth of the appropriate theatrical role for that character as the basic and inherent element of the artwork, within his working system in the pattern of vocal behavior as well as motor/signal behavior as he searches for aesthetic and skill proficiency at the same time.
This is done through the viewer’s relationship with the theatrical event, which the director considers as an area of active creative activity in relation to (the work of the actor) through vocal recitation and the signs it broadcasts in order to fulfill the requirements of the dramatic situation and what it requires of a visual vision drawn in t
Jurisprudential rules, a broad section to lower the legitimacy of the ruling on the developments of politics, which is increasing day by day, and developments of complex judicial issues, provided that the rule derived from the texts of the legitimate or verbal significance.
And the introduction of jurisprudence rules in the provisions concerning the legitimate policy, the first to take from the provisions of the situation; because the rules of jurisprudence is a summary of the provisions reached by the scholars of the nation after study and scrutiny, which is qualified and largely to cover the need of the owners of public mandates.
Chapter One : the importance of research and the need for it .
He has developed the concept of the curriculum has evolved as other educational concepts . Because the world has become a small village due to modern technology and are used in various aspects of life , and the rapid communication between the world can be accessed easily and conveniently . And that the purpose of education citizens who create social functions which ones to keep the culture , upgrade and repair flaws, and aims to develop the capacity of the individual and the preparations in the footsteps of scientific and technological development .
- The goal of research : The research aims to:
1 . What is the