Background: One of the drawbacks of vital teeth bleaching is color stability. The aim of the present study was to evaluate the effects of tea and tomato sauce on the color stability of bleached enamel in association with the application of MI Paste Plus (CPP-ACPF). Materials and Methods: Sixty enamel samples were bleached with 10% carbamide peroxide for two weeks then divided into three groups (A, B and C) of 20 samples each. After bleaching, the samples of each group were subdivided into two subgroups (n=10). While subgroups A1, B1 and C1 were kept in distilled water, A2, B2, and C2 were treated with MI Paste Plus. Then, the samples were immersed in different solutions as follow: A1 and A2 in distilled water (control); B1 and B2 in black tea; and C1 and C2 in tomato sauce for half an hour/day for seven days. Using a colorimeter, Teeth color measurements were recorded at baseline, after bleaching, staining, and polishing. Color changes were recorded according to the Vita shade guide and the CIE Lab system. Student's t-test was used to analyze differences between the subgroups at p<0.05. Results: Significant color changes were recorded for the tea group after staining, but not after polishing (p<0.05). No significant differences in color measurements were recorded between the subgroups of each group at all periods (p>0.05). Conclusion: Only tea produced clinically perceivable color change of bleached enamel after staining as well as after polishing. MI Paste Plus did not affect enamel color change for all the groups.
In this paper, a novel flow control strategy which is the inlet throttled pump was used to design an angular velocity control system for rotary actuator. Inlet throttled systems have good performance in addition to their high efficiency compared to traditional valve controlled systems. The flow in the proposed system is adjusted by a valve that is positioned at the pump inlet with the purpose of reducing the energy loses across the valve. This regulated flow is used then to control the actuator angular velocity. The system was modeled and the open loop stability and performance were studied. In order to improve the system performance, Robust-Proportional-Integral-Derivative (RPID) and structured singular value (M@#@) controllers have been d
... Show Moreresearch aim :
- The research aimed to investigate the effect of two treatment
methods in the gaining of fourth grade students in geography
object.
- Research hypothesis
there are no statistically significant differences at the level of ( 0.05 )
in the average level of achievement in geography between the first
experimental group ( strengthening lessons ) and the second group
( re- teaching )
no individual differences statically significant at the level of ( 0.05 )
in the average level achievement in geography object of the second
experimental group ( re- teaching ) and the first experimental group
( strengthening lesson )
the research sample : the researcher selected randomly Baghdad
The research seeks to find out the extent of the coverage of the Mosul press to the issues of psychological and social effects of the organization "IS" on the community of Mosul, by analyzing the content of the newspapers “Economic City” and “Mosul News”. As well as to stand at the types of psychological and social effects and their repercussions on the Mosul community including figures, statistics and evidence that were covered in the theoretical study of these topics.
This study is the first scientific diagnosis to reveal the size and types of psychological and social effects of the “ISIS” organization through what was monitored by the Mosul press. The study seeks to draw the attention of officials, decision-m
... Show MoreAcademic achievement is a professional standard for measuring student levels in the first stages. Therefore, any indication of the level of achievement makes us in an attempt to employ students in evening schools. The researcher has developed a closed questionnaire of (36) paragraphs. A total of (164) male and (24) female students were chosen from evening schools. The result of this research revealed that the number of students was a reason for the low level of their achievement, the lack of laboratories, educational methods, and techniques of the most prominent problems confirmed by students in these schools. In addition, to support educational institutions with their necessary needs. The most important conclusion in this research is th
... Show MoreThis study aimed to study the effect of Ziziphus spina christi Aqueous cold and Alcoholic leaves and fruits extracts on the growth and activities of the following types of bacteria :( Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Streptococcus pyogenes ). The results appeared outweigh the alcoholic extract of leaves and fruits of Sidr that prepared by saxholate extractor by addition of ethanol 95% significant superiority as compared with aqueous extract that prepared by using distilled water as was its influence inhibitor to the growth and effectiveness of bacteria , about the treatment of in-vivo to cause injury to these types of bacteria diagnosed laboratory mice and treated with alcoholic extract of the leaves o
... Show MoreThe research aims to use performance indicators and financial criteria in evaluating the economic feasibility of the company's insurance portfolios. In addition to identifying the strengths and weaknesses in portfolio's performance to enhance the strengths and address the weaknesses. This is consistent with research problem that dealt with the performance indicators, economic feasibility of company's portfolios and contributing to their improvement, reducing the financial and insurance risks associated with company's business. The research’ sample is represented by the Iraqi Insurance Company as it is one of the oldest financial institutions operating in the insurance sector. It has identified (5) insurance portfolios (marine, engineer
... Show MoreRecently, environmental noise has arisen from various sources, such as those from exhaust mufflers of combustion engines found in cars, trucks, or power generators, which produce significant noise during their operation. Controlling the radiated noise from these mufflers is a major factor in improving acoustic comfort and minimizing the impact on the surrounding communities. Numerous research has been presented for this reason by modification of the internal structure of the exhaust muffler. The main objective of this work is to reduce the noise level emitted from exhaust mufflers. This can be achieved by adjusting structure parameters to attenuate the surrounding environment's radiated noise. Analysis of pressure-wave propagation h
... Show MoreThe Iraqi-Kuwaiti relations represent a great issue for the Arab-Arab relations. This relation is characterized by specificity for the tension since the foundation of the State of Kuwait until late. There are many factors that prevented the fulfillment of the aspiration towards the development of the relations, perhaps the most important of which is the issue of Mubarak Great Port which is a difficult issue as far as the relation between the two states is concerned. One year after Iraq put the cornerstone of the Great Faw Port. This is considered as the most important hurdle in front of constructing the relations with the neighbor Kuwait
Background: Red clover oil (Trifolium pratense) has isoflavones bunches which have estrogen-like exercises and may establish an option in contrast to hormone substitution treatment. The present study investigated the impact of Red clover oil on bone healing in rats by histomorphometric study. Materials and Methods: Intra bony defect was performed in right femur of thirty six healthy male albino rats. Then these rats were randomly divided into three groups (12 rats each): one control and 2 experimental groups. For control, the bony defect was left for normal healing; for the experimental (S) group, the defect was treated with hemostatic absorbable gelatin sponge; and for experimental (RS) group, the bony defect was treated with 0.2 ml red
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