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
A collection of 118 specimens of Iraqi phasianid birds belong to four species was examined
for haematozoa. Results show that 21.2% of them were infected with one or more of four
species of blood parasites; Haemoproteus danilewskyi, H. santosdiasi, Plasmodium sp. and
microfilaria. Haemoproteus danilewskyi is reported here for the first time in Iraq.
Objective: This study aims to evaluate nurses' practices regarding electronic nursing documentation
Methodology: 40 nurses have been chosen for a pre experimental sample using a non-probability (purposive) method between November 20, 2021, and March 1, 2023. The pretest and posttest comparisons included the same group that had been exposed to the software.
Results : table the nurses' practices toward electronic nursing documentation was described as poor and fair it means that nurses practices need to be improved and developed by an interventional program. there is no significant differences between age, gender and years of employment variables and nurses practices.
... Show MoreThe purpose of this research is to study the organic planning in the United Industry Alliance, focusing on an applied model. It takes the concept of good planning, and its importance in the overall picture, well into political, economic, and military policy. It also analyzes how the United States has used this year to address the challenges that nationalism targets. The research draws on typical examples to illustrate the differences between researcher and decision effectiveness. It also discusses the factors that lead to the success or failure of dynamic planning, and draws lessons from it in other countries. Finally, the researcher begins to help in planning the goal as a basic tool in enhancing effectiveness.
Most cities in the world are suffering from the problem of solid waste and the resting adverse impact on the environment and public health, in particular the spread of diseases, insects and rodents, As well as the proliferation of nuisance odors result of provided by the responsible parties, As wall as weak environmental awareness among those who dwell in dealing in environmentally sound disposal of solid waste, this study was bembgesan first intake of solid waste and the kinds of concept and components by land use, As wall as the effects of solid waste on the environment spatial, factors affecting the quality and quantity of solid waste, the second topic was included as a study field presented the historical city of Baghdad
... Show MoreThe aim of the research is to determine the impact of evaluating the investment projects in the development and preparation of investment budgets prepared by the economic units, since the investment projects are of an important and vital nature of the economic units, because these projects include the length of time for preparation and implementation and the accompanying period of this risk and uncertainties as well as need To the many funds to complete the project , The process of evaluating the implemented projects, which have been prepared an investment budget previously will contribute to the extent of matching the estimated data with the actual results or deviations, which is a step to avoid these errors in future p
... Show MoreThe Almighty Allah has addressed His followers by advising them to follow the example of the prophet (PBUH). Allah says: (INDEED IN THE MESSENGER OF ALLAH YOU HAVE A GOOD EXAMPLE TO FOLLOW). So, He was a true and everlasting example for the people to follow and imitate in all aspects of life. Knowledge and learning, especially Qura'nic knowledge, are among the priorities.
The present study is concerned with how to follow the Prophet example (PBUH) in the field of Qur'an reciting. It aims at showing His instructions on Qur'an reciting, and how He was followed by His Companions. The present study falls into an introduction and four sections. Section One deals with the commands given by Allah to follow His prophet. Second Two
... Show MoreSerial tendering is better than other types of tendering when it comes to cost reduction, where civil infrastructure projects need a significant increase in the amount of tough planning, financial expenditures, engineering work, and resources of a different character than other types of construction projects. The effects of a lack of funding cause decrease in the completion speed of the project on time. The need to reduce the cost of bidding on recurrent civil infrastructure projects is critical. To achieve the desired goals of this research, this article will provide an overview of the type of bids used in the construction of schools implemented in the current financial perspective i
The indicators were important core for any work, and may be occurring this indicators way of communicating among planers and decision makers, even also for public participating, do make any decision. The urban and regional planning is one of those science highly depending on using indictors, for two reasons, first, way to communicating ideas between specialist and non-specialist, (politician and decision makers), the second one, this field are multidisciplinary science, so the need indictors to clearing thoughts among different backgrounds in one team, as common language.
This research tries to clear importance of GIS in forming and building Spatial Planning Indicators, to cross communication problem among planning g
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