Background: White spot lesion is the first visible sign of dental caries that is characterized by demineralized lesion underneath an intact surface. Several studies demonstrated that they could be treated using noninvasive techniques like the use of fluoride or casein phospho-peptide and amorphous calcium phosphate. Improvement in aesthetic outcomes by covering the demineralized enamel is one of the advantages of the use of resin infiltration and opal-ustre microabrasion, which are two new techniques that had been used for treatment of white spot lesion. The purpose of this study was to evaluate the impact of resin infiltration and microabrasion in the microhardness of the artificial white spot lesions at various depths. Material and method: Forty-eight artificially white spot lesions were divided into three groups (n=16) according to the depth of the lesion (shallow enamel, deep enamel, shallow dentine). Then, each of the main groups was divided into two subgroups (n = 8), the first group was treated with resin infiltration, while the second one was treated with Opalustre microabrasion. Assessment of the microhardness was done using Vickers hardness at the baseline, after demineralization (formation of the white spot lesion) and after the treatment with the resin infiltration and the microabrasion. Results: There was a significant difference in the microhardness of all the layers after demineralization. Although the hardness values that found among the icon group in the inner enamel and the outer dentine were higher than that of the opalustre, statistically there was no significant difference between the two mate-rials in all the layers of the white spot lesion. Conclusion: Microhardness values decrease as the depth of the white spot lesion increase. There was an increase in the microhardness values after the treatment with the resin infiltration and the microabrasion.
In this article, the detailed information was presented about azo-dyes, including a general description of this class of compounds, which included a historical overview, observations on the chemical structure of these compounds, particularly focusing on the azo group (-N=N-) responsible for their coloring properties. In addition, we provided a schematic of the first synthesized azo-compound. Furthermore, we mentioned the general properties of them and viewed a detailed explanation for the categorization of them either aliphatic or aromatic, subdivisions for each category or which category is the most widespread, and then illustrated the types for this class of organic compounds. The effective operator in these compounds called diazonium-sal
... Show MoreThe research aimed at identifying the effect of the think, pair, and share strategy by using educational movies on learning jumping opened legs and closed legs skills on vault in artistic gymnastics for women. It also aimed at identifying the group that learned better the skills understudy. The researcher used the experimental method on second-grade College of Physical Education and Sport Sciences female students. Twelve female students were selected from each of the two sections to form the subjects of the study. The main program was applied for eight weeks with one learning session per week. The data was collected and treated using SPSS to conclude that the think, pair, and share strategy and the traditional program have positive effects
... Show MoreThe present study aims at identifying the effect of organizational pressure with its aspects (management, work team, nature and conditions of work, external environment) on job performance in all its dimensions (commitment and effort made, capabilities and the rapidity of performance, motivation and job satisfaction, work environment) for the university teacher at the Faculty of Economics, Commercial and Management Sciences at the University of Djelfa, Algeria.
In this research, the descriptive analytical approach is used. Data was collected through the distribution of a questionnaire to a sample that included 130 permanent teachers before being analyzed using the (SPSS) statisti
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This research worked on identifying the effect of increasing the volume of indebtedness by companies listed on the Iraq Stock Exchange on the trading volume of those companies, and this research included some theoretical concepts related to both debt financing and trading volume, and it represents the research community of the joint-stock companies listed in The Iraq Stock Exchange (the banking sector). As for the research sample, it was deliberately chosen represented by companies with continuous trading without stopping, which reached 10 joint-stock companies, and the period of research was extended during the period 2011-2015, and a set of indicators and financial methods were used In measuring research v
... Show MoreIn this investigation a high density polyethylene (HDPE) was used as a substitute to polyvinylchloride in the production of lead acid battery separators. This has been achieved by preparing mixtures of different percentages of the feed materials which include a high density polyethylene (HDPE) locally produced, filler materials such as silica and oils such as dioctylphthalate (DOP) or paraffin which were added to the mixture to improve the final properties of the separator. The materials were compounded by two roll-mills under the same conditions. The following parameters are involved: &nb
... Show MoreThis work is concerned with the study of the effect of cement types, particularly OPC and SRPC, which are the main cement types manufactured in Iraq. In addition, study the effect of mineral admixtures, which are HRM and SF on the resistance of high performance concrete (HPC) to internal sulphate attack. The HRM is used at (10%) and SF is used at (8 and 10)% as a partial replacement by weight of cement for both types. The percentages of sulphate investigated are (1,2 and 3)% by adding natural gypsum as a partial replacement by weight of fine aggregate. The tests carried out in this work are: compressive strength, flexural strength, ultrasonic pulse velocity, and density at the age of 7, 28, 90 and 120 days.
The r
... Show MoreSports skills in some individual games require physical and motor qualities to facilitate the process of skill performance and also require the instructor or trainer to use more than one strategy, method and way to bring the performance to the level of mastery and avoid injury. The aim of the research is to know the effect of using special exercises using tools and their effect on teaching the skill of a front shoulder circle. The research hypothesis is that using special exercises with tools has a positive effect on teaching the skill of a front shoulder circle on the rings apparatus. Research method: - The researchers used the experimental method by designing two equal groups, the control and the experimental, to suit the research
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