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.
This research was aimed to study the pollen morphology for the genus Pterocephalus(Vaill) from Dipsacaceae family in Iraq, and to utilize these feathers in isolating the species as valuable taxonomic traits for enriching Iraqi flora. The study included characteristics of the type, shape, size, sculpturing and apertures, as well as determining the full dimensions using light microscopy as well as numerical analysis of this species and draw polygonal shapes and denderogram convergence between species. The results of the study of pollen and polygonal forms showed significant differences in the characteristics at the level of each species, which helps to identification the genus species, as it was found that the pollen was a tricolp
... Show MoreThe researcher tried to concentrate on the field study included many houses for the sake of documenting it by pictures and schemes with its history using the available data that had got from elderly whereas the rest of heritage will document in other research , in God willing .
The research confined on the studying of examples heritage houses which was some of them had built at the end of 19th century AD but, other of them had built on the beginning of 20th century . In spite of considering these buildings are important and as a sign to architect art of Jubba but, there is never full studying written about them in Western city .
The importance of this study lies on documenting sides of environmental and climatic progress which Iraq
In line with the most recent trends in genre analysis (Swales, 1990; Bahatia,
1993) and discourse studies on business communication (Dudley-Evans and St.
John, 1998;Bargiela-Chiappini, F. and C. Nickerson, 1999, the article focuses on a
particular financial genre, Bank's Annual Reports (ARs). More in detail, in contrast
in widespread claim about the purely financial and informative nature of ARs,
addressing experts only, this paper aims at illustrating in accordance with Bexley
and Hynes (2003), and Burrough's (1986) considerations, that those reports
endeavour to promote the company image and to leave a positive impression on
readers. Generally speaking, companies communicate because they exist: they have
a na
BACKGROUND : Bifurcational coronary lesions are
frequent and amounts to almost one fifth of routine
practice concerning up to 15 – 20 % of cases .
Revascularization by percutaneous coronary
intervention ( PCI ), of bifurcational lesion has
become easier by stenting yet it remains a frequent
challenge.
OBJECTIVE : To evaluate the success and hospital
complications of two most frequent technique of stent
deployment in bifurcational PCI.
METHODS : We prospectively analysed the data of
140 consecutive patients with bifurcational PCI at
Ibn_Al-Bitar Hospital for cardiac surgery for the
period from July 2008 to July 2009 .
Depending on whether the side branch was stented or
not, the patient has fa
Palladium nanoparticles are produced by Polyol method. The characterization of the Pd nanoparticle has been conducted by various techniques such as SEM and AFM. The results of Pd powder showed that the particle size is directly proportional to the temperature and the reaction time. The optimum conditions for obtaining minimum nanoparticles size are 45 oC reaction temperature and 60 min reaction time and the smaller particle size achieved is equal to 25 nm. The optical limiting of smaller size nanoparticles has been studied. The palladium nanoparticles appear to be attractive candidates for optical limiting applications.
The aim of this paper is to translate the basic properties of the classical complete normed algebra to the complete fuzzy normed algebra at this end a proof of multiplication fuzzy continuous is given. Also a proof of every fuzzy normed algebra without identity can be embedded into fuzzy normed algebra with identity and is an ideal in is given. Moreover the proof of the resolvent set of a non zero element in complete fuzzy normed space is equal to the set of complex numbers is given. Finally basic properties of the resolvent space of a complete fuzzy normed algebra is given.
Given the importance of ecology and its entry into various fields in general and the urban environment particularly; ecological cities take wide ranges of application at multiple regional and global levels. However, it repeatedly noted that there was a state of cognitive confusion and overlapping in the term ecology comes from the diversity of implementation within several disciplines. Architects, designers, and planners have instilled biological development directly into the formal principles as well as the social structures of the ecological cities. Therefore, the research presents a rapid review of the most relevant areas that dealt with the ecological cities by research and analysis at various levels, from the concept and definition of
... Show MoreMost heuristic search method's performances are dependent on parameter choices. These parameter settings govern how new candidate solutions are generated and then applied by the algorithm. They essentially play a key role in determining the quality of the solution obtained and the efficiency of the search. Their fine-tuning techniques are still an on-going research area. Differential Evolution (DE) algorithm is a very powerful optimization method and has become popular in many fields. Based on the prolonged research work on DE, it is now arguably one of the most outstanding stochastic optimization algorithms for real-parameter optimization. One reason for its popularity is its widely appreciated property of having only a small number of par
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