It is found that hypersensitive teeth have a larger number and wider patent tubules than those of non-sensitive teeth. Objective: The aim of this study is to compare between the effects of diode laser at different power densities, with and without sodium fluoride on the sealing of exposed dentinal tubules and dentin permeability. Materials and methods: 118 teeth were used. Samples were divided into three major groups. The first consisted of 100 teeth used for permeability test. The second consisted of 16 teeth for measuring external surface temperature elevation while irradiation. The third, in turn, consisted of one pair of teeth observed under SEM for dentine surface morphology analysis. Results: For dentin permeability measurement, the results revealed a highly significant difference between the control group and 2, 3 W with varnish groups. For the external surface temperature elevation, the results revealed that temperature rise, for both laser alone and with varnish groups, was between (67-97.9 ∘C) at 1.6, 2 W. SEM analysis revealed that approximately optimum sealing of tubules occurred in 2W with the varnish group. Conclusions: The combined application of 940 nm diode laser at 2W with 809.7 W/cm² power densities, with sodium fluoride white varnish show a significant improvement in their effects on dentin permeability reduction as compared to each treatment alone.
תקציר
העיון הזה מדבר על דבר ההשגה על הטקסטים המקראיים בידי כמה מסופרים ופילוסופים יהודים אשר הושפעו מהרעיונותיהם של הפילוסופים האירופיים מחד גיסא, ואת הרעיונות של ההשכלה מאידך גיסא. היהודים היו חיים בבידוד, ותחת השליטה של הרבנות (רבנים) שהייתה שליטה מוחלטת. כבר העבודה של הרבנות מאז ימי קדם להעלות רעיונות במוחם של היהודים בתור העם הנבחר, והם מעולים ועדיפים על בני אדם. הם כל כך מסתמכים על פסוקים מה
... Show MoreMuch has been written about Baghdad in the history books and documents ,about the Origin of its call , Reality ,history ,peoples ,Rulers and all that have passed since the beginning of creation and so far...
The searchers opinions are variant in determining the extent of impacting political risk in the host country on foreign direct investment decision. (Aharoni,1966) found, in his questionary study for group of foreign companies operating in India, that a political stability is one of the two most important factors, besides the market size, in the attraction of foreign investment, and its availability means that whether this specific country is good for foreign investment. On the other side, (Green and Benntt, 1972) are present a variant opinion to Aharonis opinion. They are reach to result state that a political instability do not impact on the general distribution of foreign i
... Show MoreHighlights the role of taxes in being a major source of funding sources internal economic and social development, and then, any decrease in tax revenue caused by tax evasion, for example, would weaken the government's ability to finance their investments and core financing private sector investment as a result of reduced ability to increase their reserves's cash banks, as well as the weakening of the effectiveness of tax evasion taxes as a tool to guide economic activity in the framework of service for development, and to achieve justice. And the statement of the reasons for and methods of evasion mandated to pay the tax due on them, whether legitimately or illegal with the statement of the proposed methods to tackle tax evasion and elimina
... Show MoreThe design and implementation of an active router architecture that enables flexible network programmability based on so-called "user components" will be presents. This active router is designed to provide maximum flexibility for the development of future network functionality and services. The designed router concentrated mainly on the use of Windows Operating System, enhancing the Active Network Encapsulating Protocol (ANEP). Enhancing ANEP gains a service composition scheme which enables flexible programmability through integration of user components into the router's data path. Also an extended program that creates and then injects data packets into the network stack of the testing machine will be proposed, we will call this program
... Show MoreAbstract
The developments of technology and information that is sweeping the world based on the factors of pressure on the accounting profession in general, and the authors of the accounting information. That becouse the makers of administrative decisions have become in need of new information fit and the environmental situation of the new competition and try to enter new markets,
... Show MoreWhat linguists mentioned about the infinitive and its use in the linguistic levels of speech, whether with its verb, or what was mentioned in the difference between the infinitive and the noun of the source, are matters that are related to the phenomenon of hearing in speech, a need necessitated by the nature of the linguistic law
Acceptable Bit Error rate can be maintained by adapting some of the design parameters such as modulation, symbol rate, constellation size, and transmit power according to the channel state.
An estimate of HF propagation effects can be used to design an adaptive data transmission system over HF link. The proposed system combines the well known Automatic Link Establishment (ALE) together with variable rate transmission system. The standard ALE is modified to suite the required goal of selecting the best carrier frequency (channel) for a given transmission. This is based on measuring SINAD (Signal plus Noise plus Distortion to Noise plus Distortion), RSL (Received Signal Level), multipath phase distortion and BER (Bit Error Rate) fo
... Show MoreSteganography is a mean of hiding information within a more obvious form of
communication. It exploits the use of host data to hide a piece of information in such a way
that it is imperceptible to human observer. The major goals of effective Steganography are
High Embedding Capacity, Imperceptibility and Robustness. This paper introduces a scheme
for hiding secret images that could be as much as 25% of the host image data. The proposed
algorithm uses orthogonal discrete cosine transform for host image. A scaling factor (a) in
frequency domain controls the quality of the stego images. Experimented results of secret
image recovery after applying JPEG coding to the stego-images are included.