Background: one of the complications of power bleaching is surface roughness of enamel which increases the possibility of post bleaching teeth discoloration. The aim of the present study is to evaluate the effect of toothpaste containing nano hydroxyapatite, NovaMin and kin sense fluoride on surface roughness of human tooth enamel after laser bleaching with 35% hydrogen peroxide bleaching gel. Materials and Methods: Twenty human enamel incisors were cleaned and their labial surface polished up to #1200, then categorized into four equal groups; first group kept without bleaching as a control group, while the remaining three experimental groups were bleached with 35% hydrogen peroxide, and each group treated with a restore paste containing one of the following: nano hydroxyapatite, NovaMin, and Kin fluoride. Bleaching was done with laser hybrid system (DMC Whitening Lase II, Sao Paulo, Brazil). Enamel roughness values assessed by an atomic force microscopy (AA3000, Bosten, USA) before and after treatment with restore tooth paste. Results: Paired t-test used to compare the mean roughness values before and after treatment with each restore paste. One-way analysis of variance and Duncan post hoc tests used to determine the differences between mean roughness values of the groups. A p-value of 0.05 or less considered a significant. The results showed a highly significant statistical differences of remineralization of all types of restore tooth pastes. Conclusions: Nano hydroxyapatite past exhibiting a higher ability to reduce the surface roughness after laser bleaching than other tested pastes.
Among a collection of leafhoppers from Erbil Province in Kurdistan/Iraq, a new species of the genus Arboridia Zakhvatkin, 1946 was designated and described here as a new species to the science. The erection of this species was mainly built on the external characters included the male genitalia. Sites and dates of collections so as the host-plants were verified.
The adsorption of Cr (VI) from aqueous solution by spent tea leaves (STL) was studied at different initial Cr (VI) concentrations, adsorbent dose, pH and contact time under batch isotherm experiments The adsorption experiments were carried out at 30°C and the effects of the four parameters on chromium uptake to establish a mathematical model description percentage removal of Cr (VI). The
analysis results showed that the experimental data were adequately fitted to second order polynomial model with correlation coefficients for this model was (R2 = 0.9891). The optimum operating parameters of initial Cr (VI) concentrations, adsorbent dose, pH and contact time were 50 mg/l, 0.7625 g, 3 and 100 min, respectively. At these conditions, th
The insulation system of a machine coil includes several layers made of materials with different characteristics. The effective insulation design of machine coils, especially in the machine end winding, depends upon an accurate model of the stress grading system. This paper proposes a modeling approach to predict the transient overvoltage, electric field, and heat generation in machine coils with a stress grading system, considering the variation of physical properties in the insulation layers. A non-uniform line model is used to divide the coil in different segments based on material properties and lengths: overhang, stress grading and slot. The cascaded connection of chain matrices is used to connect segments for the representation of the
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Two Schiff base ligands L1 and L2 have been obtained by condensation of salicylaldehyde respectively with leucylalanine and glycylglycine then their complexes with Zn(II)were prepared and characterized by elemental analyses , conductivity measurement , IR and UV-Vis .The molar conductance measurement indicated that the Zn(II) complexes are 1:1 non-electrolytes. The IR data demonstrated that the tetradentate binding of the ligands L1 and L2 . The in vitro biological screening effect of the investigated compounds have been tested against the bacterial species Staphlococcus aureus, Escherichia coil , Klebsiella pneumaniae, Proteus vulgaris and Pseudomonas aeruginosa by the disc diffusion method . A comparative study of inhibition values of
... Show MoreThe local authority represented by the Provincial Council and the administrative units thereof has legislative and supervisory functions which are in the administration and supervision of the local public utilities as provided for by the laws in force. The subject of the interactive relationship between the federal authority and the provincial councils not organized in one of the main problems that accompanied the emergence and application of decentralized system Iraq after 2003, which began since the writing of the Constitution in force for the year 2005 and the law of the provinces No. 21 of 2008 This law has been subjected to political recordings that eventually led to the appearance of this consensus image. The weakness of the legisl
... Show MoreOne of the most important virulence factors in Pseudomonas aeruginosa is biofilm formation, as it works as a barrier for entering antibiotics into the bacterial cell. Different environmental and nutritional conditions were used to optimize biofilm formation using microtitre plate assay by P. aeruginosa. The low nutrient level of the medium represented by tryptic soy broth (TSB) was better in biofilm formation than the high nutrient level of the medium with Luria Broth (LB). The optimized condition for biofilm production at room temperature (25 °C) is better than at host temperature (37 °C). Moreover, the staining with 0.1% crystal violet and reading the biofilm with wavelength 360 are considered essential factors in
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