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
Photobiomodulation (PBM) is a form of the use of visible red and Near-infrared (NIR) light at low power, where a laser light photon is absorbed at the electronic level, without heat production. PBM can be applied in wide range of treatment to help the wound, inflammation, edema, and pain reduction. However, there is a lack of scientific documentation regarding its actual effects. Objectives: This study assesses the impact of PBM on the release of M1-related cytokine in monocyte cells with particular emphasis on interleukin-1β (IL-1β) and Tumour Necrosis Factor α (TNF-α). Methods: Tamm-Horsfall Protein 1 (THP-1) macrophages M1 cells have been exposed to the light from the diode laser of 850nmat different doses (0, 0.6, 1.2 and 3.
... Show MorePurpose: To evaluate the effect of intravitreal Aflibercept injection on wet AMD both functionally and anatomically after loading doses. The secondary aim is to evaluate the effect of risk factors including (gender, age, smoking, hypertension, and diabetes meatus) on the patient’s response. Study Design: Interventional case series. Place and Duration of Study: Al-Haitham Eyes Teaching Hospital in Baghdad, Iraq, from November 2021 and September 2022. Methods: Fifty eyes of 47 patients with treatment naïve wet AMD were selected through convenient sampling. Data were collected for age, gender, smoking, and chronic disease. Clinical examination, best corrected visual acuity (BCVA), optical coherence tomography angiography
... Show MoreThe article considers metaphors as one of the fundamental means used by L. Ulitskaya when writing the family chronicle "Medea and her Children" (1996), for the formation of images of heroines - representatives of the pronounced feminine principle in the work. Here I describe the results of the next stage of research related to the work of Lyudmila Evgenievna Ulitskaya as a representative of modern Russian prose.
Prison and imprisonment
And their impact on the strengthening of power
In the Qur'anic perspective
Background: The success and maintenance of indirect dental restorations is closely related to the marginal accuracy, which is affected by many factors like preparation design, using of different fabrication techniques, and the time of taking final impression and pouring it. The purpose of this in vitro study was to evaluate the effect of different pouring time of conventional impression on the vertical marginal gap of full contour zirconia crowns in comparison with digital impression technique. Materials and Methods: Forty sound recently extracted human permanent maxillary first premolar teeth of comparable size and shape were collected. Standardized preparation of all teeth samples were carried out to receive full contour zirconia crown re
... Show MoreBackground: The success and maintenance of indirect dental restorations is closely related to the marginal accuracy, which is affected by many factors like preparation design, using of different fabrication techniques, and the time of taking final impression and pouring it. The purpose of this in vitro study was to evaluate the effect of different pouring time of conventional impression on the vertical marginal gap of full contour zirconia crowns in comparison with digital impression technique. Materials and Methods: Forty sound recently extracted human permanent maxillary first premolar teeth of comparable size and shape were collected. Standardized preparation of all teeth samples were carried out to receive full contour zirconia crown re
... Show MoreA polycrystalline CdTefilms have been prepared by thermal evaporation technique on glass substrate at room temperature. The films thickness was about700±50 nm. Some of these films were annealed at 573 K for different duration times (60, 120 and 180 minutes), and other CdTe films followed by a layer of CdCl2 which has been deposited on them, and then the prepared CdTe films with CdCl2 layer have been annealed for the same conditions. The structures of CdTe films without and with CdCl2 layer have been investigated by X-ray diffraction. The as prepared and annealed films without and with CdCl2 layer were polycrystalline structure with preferred orientation at (111) plane. The better structural pr
... Show MoreThe diversity of cultures is still the title of an Iraqi specificity that gave the society a diversity and this is reflected in the journalistic reality with the changing of the political system generate a new political and ideological life that differs from what is prevailed during the decades. However, its exacerbation of the degree of division is an additional duty for the press as a cultural platform and a knowledge bridge that contributes to the process of dialogue, addressing the differences, establishing a politically homogeneous structure through the state and socially by uniting all components of society and working to raise public awareness of the importance of national belonging to build a modern state. Cultural diversity is a
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The goal of current research to describe and diagnose the level of attention of doctors to design and regulatory dimensions, (strategic vision, organizational structure, organizational processes, business systems, personnel), and the performance of hospitals and dimensions, in six hospitals in medicine and selected a sample for research, as well as identify organizational design effect in the performance of hospitals and dimensions (efficiency, the development of human resources, patient satisfaction, achieve financial results, quality of health care).
Research has focused in part theoretical on key variables to look organizational des
... Show MoreAbstract The aim of this study is preparing an intellectual map according to the feedback (verbally and writhingly ) in order to learn some skills of floor exercises in the women's artistic gymnastics , In addition to that the aim of this study defines on the impacts of intellectual map according to the feedback approach, and to identify the best group between the three groups study in the learning of skills approach in this study, the researchers used the experimental method, the subject of the study included on students second class in physical education and sport sciences , Baghdad University (2014-2015) , and divided into three groups for teaching skills which was under studied .The species used the specific manner by lot for selection
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