Background: Human teeth considered to be an important etiological host factor in relation to dental caries through its morphology and composition. Elements may incorporate in tooth structure during pre and post-eruptive period changing the resistance for caries. The aims of this study were to determine the concentration of selected major (Calcium and phosphorus) and trace elements (Ferrous iron, nickel, chromium and aluminum) in permanent teeth and enamel among a group of adolescent girls in relation to severity of dental caries Material and Methods: The study group consisted of 25 girls with an age of 13-15 years old referred by Orthodontists for extractions of upper first premolars (two sides). Tooth and enamel samples were prepared for chemical analysis according to method described by Lappalainen and Knuttila (1979). Dental caries was diagnosed by both clinical and radiographical examinations following the criteria of D1-4MFS index described by Muhlemann (1976). All data were analyzed using SPSS version 19. Results: The concentration of major elements in teeth and enamel (measured in % of dry weight) showed that Ca ions were higher than P ions. On the other hand the concentration of trace elements in teeth and enamel samples (measured in ppm) showed that Al ions was the highest followed by Ferrous Fe then Ni ions, while Cr ions were the least in concentration. All elements showed statistically highly significant difference in concentration between teeth and enamel samples. Ca/P ratio was higher in enamel than tooth, but the difference was statistically not significant. Major elements (calcium and phosphorus) in tooth and enamel samples recorded negative correlations with DMFS. Trace elements except chromium ions recorded positive correlations with DMFS. They were not significant except for nickel ions in tooth and aluminum ions in enamel. Conclusions: The presence of these elements in both teeth and enamel samples indicated that these elements present in our environment; as foods, water, and air so they incorporate through out the tooth layers during the pre-eruptive period of tooth development, and incorporate the outer enamel surface during the demineralization and remineralization processes that occurs in the post-eruptive periods. Ca and p ions play an important role in mineralization of tooth and enamel. Cr ions may play a role in improving mineralization and crystallity of teeth, while Fe, Ni and Al may act as cariogenic elements.
The importance of the research lies in preparing exercises using a proposed device to learn the skill of thehuman wheel on a machine rug of ground movements of the artistic gymnastics. As for the research problem:Through the presence of the two researchers as teachers and observers of this sport in the gymnastics hall,they noticed that there is difficulty in the students’ performance of the skill of the round off on the machineof the mat of ground movements, according to the researchers’ opinion, the reason for this is that skillsare taught with the limited availability of assistive devices, as well as the lack of use of these devices inexercises according to biomechanical variables, although they facilitate the learning process
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The method of work is not a method made by grammarians. We have found more than guidance from the ancients and contemporaries; That to the corruption of meaning; or to apparent cost Not accepted by good linguistic taste.
The research focuses,in the first place, on six fields.The most important one is
curriculum field which includes the revision of the current academic curriculums and
substitute them with recent ones, beside the rehabilitation of academic labs and factories by
providing them with modern scientific technologies employed in the world. Regarding the
economical field, it seeks to provide high-level training staffs to serve different social and
economical sectors through modern effective technological and scientific
curriculums.Whereas the social field assures the concern of different social classes who
deprived from the grace of higher education such as retirees and elderly people and to set-up
some educational and ent
Receipt date:2/17/2021 acceptance date:3/16/2021 Publishing date:12/31/2021
This work is licensed under a Creative Commons Attribution 4.0 International License.
Objective: This paper investigates the contradictions in the decision-making process of the United States, which historically proven to be successful policies in the short term, but in the long term proven to be wanting and failure. Methodology: The paper uses descriptive, historical, comparative method. A
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Hands have consistently been an important vehicle in the transmission of disease (1). Thus, thorough hand-washing remains the single most important factor in preventing infection specially in hospitals and labs.Twenty-nine non-clinical volunteers (do not work or come in contact with a clinical or hospital setting) that lacked visible skin injuries, eczema or apparent skin disease were used, those subjects were all tested by a material of each of the three used in the study weekly and laboratory tests were done pre- and post washing.All three material were effective , Eugenol extract as effective as the bar and lotion soap. And this was confirmed statistically.Eugenol has a great antibacterial action even in small concentration and t
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Each era has advantages in terms of innovation and development in form, technology, style, and design in ceramic vessels, both at the level of functional and aesthetic performance, so this study aimed to demonstrate the importance of geometrical foundations in the design structure of contemporary ceramic vessels, and also to reveal the constructive skills in The structure of the ceramic figure.
The researchers used the descriptive analytical approach to suit the nature of the study, and they described and analyzed the ceramic works in terms of geometric shape systems, elements and foundations of design in construction, formal diversity in the general design of ceramic vessels, and references and sources of artwork. In addition to th
This research presents a statistical study of radiation generated from communication towers in the Nineveh Plain region Baghdeda. The intensity of radiation energy was measured at 10 meters away from the communication tower in different locations, using a (1PC XH-901 Dosimeter/ Personal Dose Alarm / Radiation Detector, dosage rate: 0.01 μSv/h to 150μSv/h) to measure the amount of radiation at various times. Energy densities were measured and compared with standard limits provided by other authorities, such as the International Committee for Radiation Protection. Results were analyzed using SPSS version 26 to implement the data. The results show that the means of the radiation levels measured at all the zones do not statistically differ
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This study is intended to examine the concept of transcultural identity in the travel book The Global Soul: Jet Lag, Shopping Malls, and the Search for Home by (Iyer, 2001). Jeffries’ model of critical stylistics (2010) (henceforth, CS) has been selected to analyze the book. To be more specific, Negation is selected to analyze the concept under study. As such, the study aims at finding out how Negation is used to portray ideological meanings representing the concept of transcultural identity in one non-fictional travel book; and finding out the ideologies related to the concept analyzed. The analysis of the data shows that Negation is a suitable analytical tool to reach the ideational meaning of the text towards the concept of tra
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The implicit pattern is one of the cultural patterns that are present in both the text and theatrical presentation and the reading of the implicit pattern cannot take place without cognitive references, whether audio or visual as well as historical references and the natural, social and psychological dimensions of communities and individuals.
The researcher, in this study, attempted to focus on the axis of the aesthetic preoccupations of the implicit pattern in the theatrical presentation and the definition of the implicit pattern. Methodologically speaking, the research problem focused on revealing the outlines and the main features in the aesthetic preoccupations that shape the i
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