Aim To develop a low-density polyethylene–hydroxyapatite (HA-PE) composite with properties tailored to function as a potential root canal filling material. Methodology Hydroxyapatite and polyethylene mixed with strontium oxide as a radiopacifier were extruded from a single screw extruder fitted with an appropriate die to form fibres. The composition of the composite was optimized with clinical handling and placement in the canal being the prime consideration. The fibres were characterized using infrared spectroscopy (FTIR), and their thermal properties determined using differential scanning calorimetry (DSC). The tensile strength and elastic modulus of the composite fibres and gutta-percha were compared, dry and after 1 month storage in simulated body fluid (SBF), using a universal testing machine. The radiopacity of the fibres was determined using digital radiography. The interaction of the composites with eugenol was evaluated and compared with gutta-percha. Data of the tensile test were submitted to two-way anova and Bonferroni tests (P < 0.05). Results The endothermic peaks obtained from the DSC studies showed that the melting point of the HA/PE composites ranged between 110.5 and 111.2 °C, whereas gutta-percha exhibited a melting point at 52 °C. The tensile strength and elastic modulus of the silanated HA/PE composites were significantly higher than those of gutta-percha (P < 0.0001) under dry conditions and 1 month storage in SBF. The gutta-percha in eugenol showed a significant increase in the polymer molar mass, whereas the silanated HA/PE composites were unchanged. Radiological evaluations demonstrated that silanated HA/PE fibres were sufficiently radiopaque. Conclusion Promising materials for endodontic applications have been developed, offering relevant benefits over the traditional materials in terms of mechanical and chemical properties
Background: Orofacial cleft is the most common craniofacial birth defect and the fourth most common congenital malformation in humans that have an effect on oral health in addition to nutrient intake affected in those children. This research aims to investigate gingival condition, dental caries experience and nutritional status among children with orofacial cleft and compare them with normal children. Materials and methods: The study group included 36 children with an age ranged (4-9) years of orofacial cleft. The control group included 37 children matched the control group in age and gender. Gingival condition measured by Gingival Index (Löe and Silness, 1963), while dental caries status was measured by (D1-4MFs/d1-4mfs) index according
... Show MoreThe study aims to examine the emotional innovation, constructive thinking, foresight, and meditation among university students. Besides, attempts to explore the relationship between emotional innovation and constructive thinking, the relationship between emotional innovation and foresight, and meditation, the relationship between constructive thinking and foresight, and meditation, finally, the relationship among emotional innovation, constructive thinking, foresight, and meditation of university students regarding the variables of gender and major. A total of (400) students were selected as a sample for the study. The results revealed that university students have a high level of emotional innovation that induce them to take positive ro
... Show MoreScience is linked to each other bonds assets, branches and even close to each other; to become a link of this type of patterns of scientific integration, and perhaps the most prominent science that saw the overlap and interdependence of science and jurisprudence and its origins, and this interdependence did not stop at the epistemological foundations of knowledge; To the branches, methods of extraction, and diligence to extend to the terminology; to find similar terms in both flags; to become those terms similar in the word and meaning and even the end, but we do not lack terms similar in pronunciation and differing in meaning; and this difference is imposed by the specificity of each science and what M E; however, approached many terms
... Show MoreThe current research deals with the study of aesthetic relations in the field of interior design and the extent to which its mechanisms achieve sensory stimulation between the internal and external spaces, to generate a continuous visual connection that is an extension of it, achieving in turn sensory stimulation for the users of those spaces. The internal and external spaces meet the desired purpose of feeling pleasure and beauty.” The current research aims to “discover the nature of aesthetic relations between the internal and external spaces and the extent to which mechanisms can achieve sensory stimulation in residential spaces.” The first topic included the concept of aesthetic relations, sensory excitement, and perception at
... Show MoreThe current paper highlights an important character represented by the American president John Tyler 1841 – 1845, who is considered the tenth American president. The importance of this paper lies in identifying his personality in terms of his upbringing and the political activities he practiced before assuming the presidency and his most significant internal achievements, which showed his decisions as a president. He was fully prepared to support national policies since they do not exceed the authorities of the states. With his achievements in the foreign policy, he was capable to draw and define the features of the American foreign relations that were in harmony with the general situation in the United States of America at that time.
... Show MoreDeveloped and underdevelopment countries, on equal terms, face the problem of budget deficiency. Budget deficiency means that the public expenditure surpasses the public revenues. This, on the international level, is one of the most serious economic problems with many direct effects on the national economy, and depends, basically, on its finance chosen method. Looking for a solution to this problem, for this reason and many other ones, has been highlighted in spite of the many attempts to reduce the role of the governmental expenditure. Budget deficiency can not be attributed to a single unique cause since it is complex phenomenons the causes of which are related to many factors contribute to its occurrence, some of which refer t
... Show MoreBackground: Thyroid surgery is most common endocrine surgery in general surgical practice. Objectives: the aim of this work is to evaluate the feasibility, benefits and outcomes of open mini-incision thyroidectomy and compared the results with that of conventional thyroidectomy. The comparison between the two groups was in term of incision length, amount of blood loss, time of operation, postoperative pain, hospital stay and the cosmetic outcomes.Type of the study: this is a single-blinded randomized controlled studyMethods: This study compared the advantages and outcomes of 22 patients subjected to mini-incision thyroidectomy (Group A) with the equal numbers of patients subjected to conventional thyroidectomy (Group B).Results: the oper
... Show MoreA numerical investigation has been performed to study the effect of eccentricity on unsteady state, laminar aiding mixed convection in a horizontal concentric and eccentric cylindrical annulus. The outer cylinder was kept at a constant temperature
while the inner cylinder was heated with constant heat flux. The study involved numerical solution of transient momentum (Navier-Stokes) and energy equation using finite difference method (FDM), where the body fitted coordinate system (BFC) was
used to generate the grid mesh for computational plane. The governing equations were transformed to the vorticity-stream function formula as for momentum equations and to the temperature and stream function for energy equation.
A computer progra
Objective: To evaluate biomarkers of insulin resistance and acute phase reactants in obese, overweight and lean subjects and investigate the associations among those biomarkers. Methodology: This cross sectional study included 158 subjects who were stratified into three groups. Group1 comprised 53 obese patients (BMI≥ 30 kg/m2); group 2 were 54 overweight subjects, and group 3 had 51 healthy lean (BMI