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
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... Show MoreLaser is a powerful device that has a wide range of applications in fields ranging from materials science and manufacturing to medicine and fibre optic communications. One remarkable
Background: Primary healthcare in Egypt has undergone significant reforms since the 1990s, including the pioneering Family Health Program (FHP). However, limited evaluation exists regarding the FHP's impact on enhancing the delivery of primary healthcare services. The primary objective of this study was to analyze and understand the efficiency and effectiveness of the FHP in altering the delivery of primary healthcare in Egypt. We aimed to outline the fundamental characteristics of the primary healthcare system, compare them between the conventional and the newly reformed FHP centers, and gauge the awareness level of these variances among key decision-makers, focusing specifically on Cairo, Egypt. Methods: This cross-sectional study employe
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... Show MoreRotaviruses, a major cause of gastroenteritis in children worldwide accounts for around half a million deaths annually. Vaccine against the virus has been recommended by the WHO to be involved in the national immunization program.To evaluate the genetic characterization of rotavirus among children with acute gastroenteritis in Babylon province is warranted. Children complained of diarrhea with rotavirus infection detected in their stool were involved in the study. The age range was 10 months to 60 months and with retrogradechecking of rotavirus vaccine history. Rotavirus genotypes were detected by reverse transcription-polymerase chain reaction (RT-PCR).A total number of 40 children with rotavirus gastroenteritis were used to examine the
... Show MoreTo determine the relationship between chronic hepatitis B virus and autoimmune celiac disease, seventy five patients with chronic hepatitis B virus of ages (8-70) years have been investigated and compared with 50 healthy individuals. All the studied groups were carried out to measure antiGliadin antibodies IgA and IgG by ELISA test and anti-reticulin antibodies IgA and IgG by IFAT. There were significant elevation (P<0.05) in the concentration of AGA IgA and IgG antibodies compared to control group. The prevalence of AGA antibodies IgA and IgG was 8% and 9.33% respectively. There were a highly significant differences (P<0.01) between studies groups. The prevalence of antireticulin antibodies ARA IgA and IgG was 6.67% and 4.0% respectively i
... Show MoreThe banks mobilize savings and channel them to the economy, whether commercial or Islamic banks and thus both contribute to increasing financial depth, the objective of this paper is to measure the contribution of the Islamic banks in increase financial depth in Iraq, and compared the role played by private commercial banks in contributing to increasing financial depth in Iraq. The paper has been applying the most used indicators of financial depth that used widely in the literatures, especially those applicable with the Iraqi economy.
The paper found via using the Autoregressive Distributed Lag Model (ARDL) that Islamic banks did not contribute to increasing financial depth in Iraq, as well as for the p
... Show MoreThe Agricultural Policy is one of the most important tools adopted by the state to guide its economic and social activities through the delivery of suitable agricultural commodities to the consumer and in return to deliver agricultural inputs to the agricultural producers at the lowest possible cost to contribute in achieving a profit that helps the agricultural product to continue in the production process with the same efficiency and ambition. So as to help increase the contribution of the agricultural sector to GDP and achieve the best picture of sustainable agricultural development.
The research aimed at identifying the reality of agricultural policies and their role in achieving sustaina
... Show Moreknowledge management and managers have a primary school principals from the standpoint of their assistants M . Dr. Suad Vegetables Abbas Research problem: The administration school require a leader administratively The efficiency and skills of management and knowledge to make it effective in the administration follows the scientific method and knowledge of those who through administrative methods emanating from the trends of modern management in the management of educational , as well as the presence of the leaders of effective management has the knowledge and know-how administrative work and how to deal with others and investment optimized for all of the resources available through the future capable of Orientalism to the extent that ou
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