Objectives To tailor composites of polyethylene–hydroxyapatite to function as a new intracanal post for the restoration of endodontically treated teeth (ETT). Methods Silanated hydroxyapatite (HA) and zirconium dioxide (ZrO2) filled low-density polyethylene (LDPE) composites were fabricated by a melt extrusion process and characterised using infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The flexural strength and modulus were determined in dry state and post ageing in simulated body fluid and fractured surfaces analysed by SEM. The water uptake and radiographic appearance of the experimental composites were also measured and compared with a commercially known endodontic fibre post. Data were submitted to one-way analysis of variance (ANOVA) and post hoc Tukey multiple comparison tests at a level of significance P < 0.05. Results The LDPE/HA composites were structurally flexible and the HA content had a significant effect on the flexural strength and modulus. A univariate analysis of variance showed no significant differences in modulus and strength (P < 0.05) post accelerated ageing in simulated body fluid with very low water uptake. The melting point of the LDPE/HA composites ranged between 135 and 136 °C, which would facilitate removal in case of retreatment using conventional dental heating devices. The inclusion of HA reduced the damping thereby enhancing dimensional stability, whilst the addition of zirconia yielded a semi-translucent material that was sufficiently radiopaque, comparable to commercial posts, thus yielding aesthetic materials. Conclusions Innovative materials for restoration of ETT were developed; offering considerable benefits over the currently available material in terms of biomechanical and thermal properties. Clinical significance This study provided a new option for the development of a new intracanal post made up of functional and aesthetic composites.
Research topic: (The Epistemological Foundations for Comparison of Religions by al-Amiri)
The research sought to study the topic with: a descriptive methodology by investigating the components of al-Amiri's approach to the interfaith comparison. And analytical, by showing the applied perception of an objective model in the comparison of religions to answer two questions: What are the cognitive foundations of al-Amiri? And what is his approach to establishing an objective comparison between religions?
The research started by introducing Abu al-Hassan al-Amiri, and then presented four topics: An introduction to al-Amiri's efforts in the interfaith comparison, his knowledge foundations, an applied model
... Show MoreIn this work, electrochemical process was presented to polymerized eugenol on Gr.2 and Gr.5 titanium alloys before and after treated by Micro Arc Oxidation (MAO), where Gr.2 is commercial pure titanium and Gr.5 is Ti-6Al-4V dental alloys. The deposited layers were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The adhesion strength of polymeric thin-film was estimation by using pull-off adhesion test and the result was the adhesion strength of PE was (1.23 MPa) on Gr.2 before MAO and increase to (1.98 MPa) on Gr.2 after MAO treatment. The corrosion behavior of Gr.2 and Gr.5 alloy in artificial saliva environment at
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This research deals will the declared production planning operation in the general company of planting oils, which have great role in production operations management who had built mathematical model for correct non-linear programming according to discounting operation during raw materials or half-made materials purchasing operation which concentration of six main products by company but discount included just three products of raw materials, and there were six months taken from the 1st half of 2014 as a planning period has been chosen . Simulated annealing algorithm application on non-linear model which been more difficulty than possible solution when imposed restric
... Show MoreThis paper compare the accurecy of HF propagation prediction programs for HF circuits links between Iraq and different points world wide during August 2018 when solar cycle 24 (start 2009 end 2020) is at minimun activity and also find out the best communication mode used. The prediction programs like Voice of America Coverage Analysis Program (VOACAP) and ITU Recommendation RS 533 (REC533 ) had been used to generat HF circuit link parameters like Maximum Usable Frequency ( MUF) and Frequency of Transsmision (FOT) .Depending on the predicted parameters (data) , real radio contacts had been done using a radio transceiver from Icom model IC 7100 with 100W RF
... Show MoreThe study explores the use of ergative verbs in constructing clauses and their impact on the backgrounding of the agent's role in two selected short stories. Contrary to hypothesis No. 1, the research indicates that changes in sentence patterns don't affect the meaning of the process. Additionally, hypothesis No. 2 is refuted as the middle structure is found to highlight the agent's role in the science fiction short story, Terra Infirmum, rather than concealing it as hypothesized for "The Invisible Man." The analysis uncovers that writers utilize ergative processes to narrate stories in various ways, including transitive/active voice, intransitive/active voice, and transitive/passive voice. Furthermore, the findings suggest that writers emp
... Show MoreThe aim of the research is to know the characteristics of both variables in order to be able the to construct the integrated framework of its paragraphs through the available information on both inspirational leadership and organizational health. as fundamental variables of research, as well as the extent of the influence of the inspirational variable as an independent variable in the organizational health variable as a variable in its three physical, mental and social dimensions. The research is important to stimulate the behavior side of the staff. Which is one of the top concerns of senior management in the ministry, because of its great importance in increasing the effectiveness of the performance of e
... Show MoreThe semiotic trend of recent monetary trends task that took a wide range of attention of critics and readers alike, especially after the deployment, which accompanied him after widespread acts critic Grimas and powers applicable to the literary texts and is thus expanded its care circle, hence the choice of the novel (absent) woman Iraqi novelist (Mahdi ‘Issa falcon) model to be applied to the study chose to be a semiotic approach through the use of procedural mechanisms for its critical tool (Paris School of semiotics), cash and views of its founder critic Grimas.The research in the introduction and pave came we made it a vision for literary semiotic and its impact trend in cash and cash is and what it desire to clarify some poked suc
... Show MoreThe purpose of this study was to know the reality of motivational administrative methods for academic decision-makers in the faculties of physical education and sports sciences in Baghdad from the perspective of faculty members. To solve the nature of the current problem, the two researchers used the descriptive approach of the survey method. The two researchers determined their research community by limiting the sample to all faculty members in the faculties of physical education and sports sciences in Baghdad (Al-Mustansiriya University, Al-Jadriya Univeristy & Al-Waziriyah University). Their number reached 314 faculty members and the two researchers determined their research community by 90%, so the research sam
... Show MoreThe study aimed at interpreting the role of architectural design quality in in build competitiveness model in accordance with the proposal included the idea of architectural design quality for its removal; interesting design factors of the environment, good design of the spaces, and design aesthetic explanatory variable. The competitiveness dimensions; the level of innovation, stimulate research, and the quality of the company's products, and activating the role of human resources, entrepreneurship, profitability, market share and competitiveness, variable responsive. The study of construction companies in the Ministry of Housing and Construction has taken the Iraqi society for the study. The sample consisted of (48) manage
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