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
Introduction and Aim: Pseudomonas aeruginosa is a nosocomial infection with an ability to develop high levels of antibiotic resistance. The efflux pump system is one of the mechanisms that is linked to multidrug resistance in P. aeruginosa. In this study, we employed siRNA loaded on gold nanoparticles against the MexA efflux pump gene to decrease the MexA gene expression in P. aeruginosa and estimated antibiotic resistance after gene silencing. Materials and Methods: This study examined four strains of P. aeruginosa isolated from patients in various hospitals in Baghdad. Bacteria isolated were identified by biochemical tests and Vitek compact 2 system. Single-stranded siRNA (33bp) designed in this study was loaded onto gold
... Show MoreBackground: The surgical extraction of impacted third molar usually results in postoperative inflammation manifested as pain, facial swelling and trismus which may cause deterioration in the patient’s quality of life. Methods: This randomized controlled study included 56 patients indicated for surgical extraction of IMTM under local anesthesia. These patients were randomly assigned into two groups: a study group that included patients who received Tibrolin® postoperatively and a control group that did not. The predictor variable was whether to use SET or not. Pain measured by the pain numerical rating scale (NRS), facial swelling, and the degree of trismus were the outcome variables. The Arabic version of the Oral Health Impact P
... Show Moreهدف البحث الى بيان طبيعة ارتباط والتأثير بين الضغوط التنافسية (المتغير المستقل) والتجديد الاستراتيجي (المتغير التابع) ، تم تطبيق البحث في فنادق الدرجة الممتازة في بغداد. وبلغت عدد افراد عينة البحث (99) مديراً يعملون في (6) فنادق من الدرجة (الممتازة) ببغداد، وهي (فندق الرشيد، فندق عشتار، فندق ميريديان، فندق المنصور، فندق بابل، وفندق بغداد) وتم اجراء التحليل الاحصائي باستخدام البرنامج الاحصائي AMOS وظهرت وجود تنافسي
... Show MoreBackground: Saliva is one of the most important etiological host factors in relation to dental caries. It affects the carious process by its organic and inorganic constituents; in addition to its physiological functions as (flow rate, pH and buffer capacity). The aims of this study were to determine the concentrations of major elements (calcium and phosphorus) and trace elements (ferrous iron, nickel, chromium and aluminum) in saliva among a group of adolescent girls, and to explore the relation of these elements, flow rate and pH with dental caries. Material & Methods: The study group consisted of 25 girls with an age of 13-15 years old. Dental caries was diagnosed by both clinical and radiographical examinations following the criteria of
... Show MoreScience occupies great importance in Islamic thought. Science and learning are considered an essential part of Islamic teachings, and this importance appears in several aspects,Among them is thatScience as a means of understanding religion :Science is a means of understanding the teachings of the Islamic religion. Islam encourages thinking and rational research to understand the Holy Quran and the Sunnah of the Prophet, enabling Muslims to direct their lives and actions in accordance with the directives of their religion,And also to encourageResearch :Islam encourages scientific research and the use of reason in understanding the nature of the universe and God’s signs in it. Muslims are encouraged to study the natural and social s
... Show MoreThe effect of chronic exposure to two different levels of cadmium chloride (CdCl2) 30 ppb and 40 ppb in drinking water for 12 weeks on thyroid function of mature male rabbits was studied. Eighteen mature male rabbits were randomly divided into three groups (each of six ) , control group (group I ): were offered ordinary tap water , and treated groups (II and III ) were offered tap water containing 30ppb and 40 ppb respectively for 12 weeks .Serum concentration of thyroxin (T4 ) and triiodothyronine (T3) were measured every six weeks ,as an index of thyroid function , further more , section of thyroid gland were prepared for histological studies. The results showed that chronic exposure of male rabbits
... Show MoreBackground: The fracture of instruments within root canal during endodontic treatment is a common incidence, fracture because of fatigue through flexure occurs due to metal fatigue, this study aimed to assess the effect of curvature angle and rotational speed on the cyclic fatigue of different type of Endodontic NiTi Rotary Instruments and compare among them. Materials and method: Three types of rotary instruments with tip size 0.25: ProTaPer F2 (Densply, Malifier) Revo-S SU( 0.06 taper, MicroMega) and RaCe system (0.06 taper, FKG, Dentaire), Forty file of each instrument were used within two canals with angle of curvature (40 &60 )at two speed (250&400)RPM, twelve group were formed for all instruments(total number=120),ten file fo
... Show MoreAbstract
The study aims to find out the degree of practicing professional leadership of the faculty’s deans, deputies, and heads of the scientific divisions at Al-Qaseem University. The study has adopted the descriptive analytical method. To achieve the objective of the study, the researcher developed a questionnaire consisting of (45) items distributed to six fields that were applied to a sample of (116) faculty deans, deputies, and the head of division at Al-Qaseem University. The results showed there is a high practicing degree of the study sample individuals of the professional leadership on the questionnaire’s fields as a whole, strategic thinking field came at the first rank, while the innovation, creat
... Show MoreThe current research aims to identify the impact of the (Landa) model on acquiring grammatical concepts among students of the College of Administration and Economics, University of Baghdad, and to achieve the research goal, the researcher has set the following hypotheses: There are no statistically significant differences at the level of significance (0.05) between the average degrees Students of the experimental group who studied the Arabic language according to the (Landa) model and the marks of the students of the control group who studied the same subject in the usual way in the post test, there are no statistically significant differences at the level of significance (0.05) in the average differences between the test scores before and
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