Background: Poly-ether-ether-ketone(PEEK) has been introduced to many dental fields. Recently it was tested as a retainer wire‎ following orthodontic treatment. This study aimed to investigate the effect of changing the bonding spot size and location on the performance of PEEK retainer wires. Methods: A biomechanical study involving four three-dimensional finite element models was performed. The basic model was with a 0.8 mm cylindrical cross-section PEEK wire, bonded at the center of the lingual surface of the mandibular incisors with 4 mm in diameter composite spots. Two other models were designed with 3 mm and 5 mm composite sizes. The last model was created with the composite bonding spot of the canine away from the center of the crown, closer to the lateral incisor. The linear displacement of the teeth, strains of the periodontal ligament, and stresses in PEEK wire and composite were evaluated. The data was numerically produced with color coded display by the software. Selected values were tabulated and compared among models. Results: The amount of linear displacement and strain was very low. Stresses in the wire and composite were affected by the size and position of the composite bonding spot. The safe limits were identified at 235 MPa for PEEK and 100 MPa for composite. The basic model had a von Mises stress in the PEEK wire of 122.09 MPa, and a maximum principal stress in the composite of 99.779 MPa. Both stresses were within the safe limits, which means a lower risk of failure in PEEK and composite. All other models had stresses that exceeded the safe limit of the composite. The 3 mm composite model was the only one that developed stresses in the wire more than the safe limits of PEEK. Conclusions: Within the limitations of this study, bonding PEEK wires with 4 mm bonding spots to the clinical crown center provided the best mechanical performance of the wires and spots; otherwise, the mechanical properties of the wire and composite would be affected and, therefore, might affect the retention process. Keywords: Retention, PEEK, Finite element analysis
Compelling evidence proved that coronavirus disease (COVID-19) disproportionately affects minorities. The goal of the present study was to explore the effects of intersected discrimination and discrimination types on COVID-19, mental health, and cognition. A sample of 542 Iraqis, 55.7% females, age ranged from 18 to 73, with (M = 31.16, SD = 9.77). 48.7% were Muslims, and 51.3% were Christians (N = 278). We used measures for COVID-19 stressors, executive functions, intersected discrimination (gender discrimination, social groups-based discrimination, sexual orientation discrimination, and genocidal discrimination), posttraumatic stress disorder (PTSD), depression, anxiety, status and death, existential anxieties, and health. We conducted in
... Show More This study examines the role played by the Iraqi media in promoting the values of citizenship and the dimensions of the various sectors of Iraqi society, an important segment namely university youth section.
The study intended to identify “the role of the Iraqi media organizations in promoting The sense of citizenship among young Iraqi university”, through: -
1. Identifying the most important Iraqi media, which works to promote the dimensions of citizenship and values.
2. To identify the extent of the contribution of the Iraqi media in promoting citizenship in dimensions (patriotic belonging, legal, political, economic, social, cultural).
The study provided a set of hypotheses, namely:-
Background: The aims of the study were to evaluate the unclean/clean root canal surface areas with a histopathological cross section view of the root canal and the isthmus and to evaluate the efficiency of instrumentation to the isthmus using different rotary instrumentation techniques. Materials and Methods:The mesial roots of thirty human mandibular molars were divided into six groups, each group was composed of five roots (10 root canals)which prepared and irrigated as: Group one A: Protaper system to size F2 and hypodermic syringe, Group one B: Protaper system to size F2 and endoactivator system, Group two A:Wave One small then primary file and hypodermic syringe, Group two B:Wave One small then primary file and endoactivator system, Gr
... Show MoreThe study of the language through the prophetic curriculum in general and the semantics in particular through the books of Professor Abdul Salam Yassin, may God have mercy on him and the most distinctive linguistic phenomena, and then study semantics and the most prominent methods that reveal the emotions dominated by this study to indicate the semantics of religious terms In this research we try to dive into the sea of significance to know the relationship between the words and their connotations, and to monitor aspects of semantic development, although we have left non-essential words in order to avoid lengthening. N or three and sometimes Aguetsarna on one example we thought it was enough to clarify the meaning.
The research aims to verify the Role of Internal Auditing in Assessing the Risks of Strategic Operations (Acquisition) and then reflect on management decisions. Since all corporations wish to expand, growth and domination of the market may expose them to multiple risks that lead to failure. The research assumes two main hypotheses. First, there is no role for internal audit in evaluating the strategic operations (acquisition). Second, there is no relationship between internal auditing in assessing the risks of strategic operations (Acquisition) and management decisions. The data was collected by using a questionnaire distributed to a group of private bank employees. The statistical analysis regarding research rejected the two hyp
... Show MoreThe purpose of this study is to assess the level of computer literacy of the students at AlQuds open university in Tulkarm Branch. The study investigates the effects of the variables of gender, specialization, academic level, owning a personal computer, internet communication, and own an email account on the level of computer literacy. A test of computer literacy was constructed by the researchers consisting of (37) multiple choice items with a reliability rate (0.85). The study population consisted of (4100) students, while the sample contained (352) students. The study revealed that the level of computer literacy of the students at AlQuds Open University in Tulkarm Branch was (66.2 %) which is educationally acceptable. It also
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The aim of the current research is to identify the level of administrative applications of expert systems in educational leadership departments in light of the systems approach. To achieve the objectives of the research, the descriptive-analytical and survey method was adopted. The results showed that the level of availability of the knowledge base for expert systems in educational leadership departments (as inputs) was low. The level of availability of resources and software for expert systems in educational leadership departments (as transformational processes) came to be low, as well as the level of availability of the user interface for expert systems in educational leadership departments (as outputs
... Show MoreThe study aims to make an in-depth analysis and the financial account components in the Iraqi balance of payments because it reflects the economic center of the country towards outside world, it also helps in making decision about monetary and financial policies, finance and foreign Trade the importance of FDI for Iraq lies as an important sources as wells provides advanced technology and job chances, It also avoids the country negative effects of borrowing processes from abroad . for analyzing direct and indirect foreign investment on the balance of payments and financial account in a period between (2003 to 2015), a community and research sample have been selected, presented in CBI/ Balance of payments. Department,
... Show MoreThe researcher seeks to get scientific facts through knowing the relationship between the priorities of Yemeni audience in follow-up paper daily newspapers compared to surfing publics the online journalism sites and the nature of information obtained from online journalism sites and printed paper newspapers and the impact of the daily newspapers in the priority of issues and political events among a sample of a group of Yemeni readers in order to identify the extent to keep up the paper daily newspapers of the development in the field of online journalism and the extent of reading paper newspapers under the intense competition by online journalism sites, and are paper newspapers able to keep pace with the actual developments provided by
... Show MoreMaxim Gorky’s Mother is one of the most important literary genre in social realism, in which he depicts female characters with revolutionary fervor and enthusiasm, projecting his social ideologies and dreams. Though the novel unique importance lies in the fact that it has been thoroughly analyzed by many writers, historians and sociologists, there are almost no studies devoted to the role of women out of a Marxist and feminist point of view. The present paper sheds light on the Russian woman‘s important role in overcoming all adversity and gain her position on Social Realism.
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