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
Most media studies on the development of the agenda have focused on the relationship between the content of the media and the audience of these media, and the extent of its impact on the agenda of the media, in addition to comparing it to the extent of interest in the agenda of those means. While in the construction of the agenda, we focus on the relationship between news sources and the media and the role of these sources in the process Building the agenda.These sources are institutions, parties, pressure groups, interest groups, the head of state and other media. The impact of these sources on the process of building the agenda are shown through the process of the selection of resources by the channel and communicators, and the technic
... Show MoreThe research includes an introduction on Unmarried as one of the most dangerous phenomena's in Arab society in general and Iraqi society in specific especially after last decades wars that ruined the country and enlarged the number of unmarried women. First chapter dealt with the research problem that was increasing day after another while the percentage of unmarried women became 85% due to embargo and wars made by ex-regime that led to kill many Iraqis and decreasing marriage chances.
The research aims to recognize the reasons behind that and tries to find solutions by using quest ways and tools to get rid of old habits that represent obstacle marriage. The research dealt with unmarried in Arab countries where National Instituti
... Show MoreSince the widespread use of the concept of human security in 1994, and as stated in the report of human development (UNDP) issued by the United Nations Development Programmer,And framed it with multiple dimensions of political, economical, social and cultural. This concept has became beyond the state and its security ,and covered all what, can threaten human life and humanitarian groups, according to the humanitarian needs in the following aspects: The economic, the food,health,environmental , individual, community and the political aspect,which totally means ,the disability of the security traditional perspective to deal with these issues.The achievement of human security,that handles the maintenance of human dignity for meeting their b
... Show MoreMultiple Sclerosis (MS) is a progressive neurological disease characterized by periods of quiescence and exacerbation, epidemiological data suggest the notion that MS is an acquired autoimmune disease caused by environmental factors, probably infectious, in genetically susceptible individuals.The submitted research was attempted to study the possible viral (Paramyxoviruses) role in MS, the sera of 57 MS patients were assayed for anti-measles and anti-mumps IgG antibodies using ELISA technique, the results were compared in order to establish the presence or absence of a significant difference regarding both number of positive cases and antibodies titer between the two groups, the results revealed that there is no in number of measles posit
... Show MoreThis review highlights the importance of photodynamic therapy in periodontology. It can be confirmed that the photodynamic therapy as adjunct to classical scaling and root planing can be recommended as treatment option, which can by no means replace the classical therapy concepts. But even over an observation period of six months a slightly higher improvement of the clinical parameters was achieved than with SRP alone.
The city is often discussed in barren, eviscerated terms and in technical jargon by urban professionals as if it were a lifeless, detached being. In fact, it is a sensory, emotional, lived experience. How often do strategic urban plans start with the words ‘beauty’, ‘love’, ‘happiness’ or ‘excitement’, as opposed to ‘bypass’, ‘spatial outcome’ or ‘planning framework, So the research problem was formed by the weakness of the sensory perception of cities and the weakness of the sense of different spaces, which in turn leads to weakness of belonging, identity and clarity, Therefor we focus here on the sensory perception. The hypothesis Recognize Senses as helpful tool in increasing people's understanding of differe
... Show MoreThis is a search for Al-Rwandiyah and its heretical deviant sects, and its destructive goals that targeted the Arab nation, and its true Islamic religion in order to exhale poisons of demolition and sabotage, leading to its racist, populist goals ( ) that the Magi aspire to to restore the so-called ancient Persian glories, and undermine the Abbasid caliphate.
Al-Biruni said: (And that a person will emerge who will restore the Magian state and seize all the land, and remove the king of the Arabs) (), and among the indications of Ibn Al-Nadim is that a populist man called Muhammad bin Al-Hussein who was turned into Zaidan () was (claiming... the transition of the Islamic state to a state Persia ..... and their religion, which is the rel