Introduction: Carrier-based gutta-percha is an effective method of root canal obturation creating a 3-dimensional filling; however, retrieval of the plastic carrier is relatively difficult, particularly with smaller sizes. The purpose of this study was to develop composite carriers consisting of polyethylene (PE), hydroxyapatite (HA), and strontium oxide (SrO) for carrier-based root canal obturation. Methods: Composite fibers of HA, PE, and SrO were fabricated in the shape of a carrier for delivering gutta-percha (GP) using a melt-extrusion process. The fibers were characterized using infrared spectroscopy and the thermal properties determined using differential scanning calorimetry. The elastic modulus and tensile strength tests were determined using a universal testing machine. The radiographic appearance was established using digital periapical radiographs. Results: The composite core carrier exhibited a melting point of 111°C to 112°C, which would facilitate removal by heat application. The elastic modulus and the tensile strength were found to be lower than those of Thermafil carriers (Dentsply Tulsa Dental, Tulsa, OK). The preliminary radiographic evaluation showed that the novel composite core carrier is sufficiently radiopaque and can be distinguished from gutta-percha. Conclusions: The PE-HA-SrO composites were successfully melt processed into composite core carriers for delivering gutta-percha into the root canal space.
The core interval at the K.H5\6 and K.H5\8 Wells in the West of Rutba provinces reveals a significant succession across the Late Cretaceous–Early Paleocene transition. The sampled interval encompasses a series of carbonates belonging to Digma Formation of Latest Cretaceous age, which underlies the Akashat Formtion of Danian age. Fifty-five species belonging to thirty-five genera were recognized. Based on the distribution of these species, eight biozones were distinguished, three biozones are recorded from the K.H 5\6 studied section and two biozones are documented from the K.H 5\8 studied section which refers to Late Maastrichtian age of Digma Formation. Five biozones are recorded from Akashat Formation in the K.H 5\6 studied section and
... Show MoreBackground: The purpose of the current study was to evaluate the efficacy of a new orthodontic bonding system (Beauty Ortho Bond) involving the shear bond strength in dry and wet environments, and adhesion remnant index (ARI) scores evaluation in regard to other bonding systems (Heliosit and Resilience Orthodontic Adhesives). Materials and methods: Sixty defect free extracted premolars were randomly divided into six groups of 10 teeth each, mounted in acrylic resin, three groups for a dry environment and three for a wet one. Shear bond strength test was performed with a cross head speed of 0.5 mm/min, while surfaces of enamel and bracket-adhesive-enamel surfaces were examined with stereomicroscope For ARI scores evaluation. Data were analyz
... Show MoreBackground: Many structural or functional abnormalities can impair the production of thyroid hormones and cause hypothyroidism.Objectives: to identify the main etiological causes of hypothyroidism among patients visiting Specialized Center for Diabetes and Endocrinology.Methods: This study was conducted in the Specialized Center for Diabetes and Endocrinology on 217 patients with proved hypothyroidism, from 2006 to 2008. Every patient was tested with thyroid function tests, Ultrasound examination, thyroid autoantibodies, fine needle aspiration, radiology of skull, isotopes scan, also checking adrenal and gonadal function. Results: Out of these 217 patients 120 patients have thyroiditis 33 patients had been undergone thyroidectomy. 39 pat
... Show MoreIn this work, an enhanced Photonic Crystal Fiber (PCF) based on Surface Plasmon Resonance (SPR) sensor using a sided polished structure for the detection of toxic ions Arsenic in water was designed and implemented. The SPR curve can be obtained by polishing the side of the PCF after coating the Au film on the side of the polished area, the SPR curve can be obtained. The proposed sensor has a clear SPR effect, according to the findings of the experiments. The estimated signal to Noise Ratio (SNR), sensitivity (S), resolution (R), and Figures of merit (FOM) are approaching; the SNR is 0.0125, S is 11.11 μm/RIU, the resolution is 1.8x〖10〗^(-4), and the FOM is 13.88 for Single-mode Fiber- Photonic Crystal Fiber- single mode Fiber (SMF-P
... Show MoreThis study was conducted for evaluating the cytotoxic effect of heat stable enterotoxin a (STa) produced by enterotoxigenic Escherichia coli on the proliferation of primary cancer cell cultures, obtained from tumor samples that were collected from (13) cancer patients and as follows: (five colon cancer patients, two bladder cancer patients, two breast cancer patients, two stomach cancer patients and two lung cancer patients), and on normal cell line (rat embryonic fibroblast / REF) (in vitro) with the use of different concentrations starting from (1) mg/ml and ending with (0.0002) mg/ml by making two fold serial dilutions by using the 96- well microtiter plate, and in comparison with negative (PBS) and positive (MMC, at concentration
... Show MoreWell-dispersed Cu2FeSnSe4 (CFTSe) nanoparticles were first synthesized using the hot-injection method. The structure and phase purity of as-synthesized CFTSe nanoparticles were examined by X-ray diffraction (XRD) and Raman spectroscopy. Their morphological properties were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The average particle sizes of the nanoparticles were about 7-10 nm. The band gap of the as-synthesized CFTS nanoparticles was determined to be about 1.15 eV by ultraviolet-visible (UV-Vis) spectrophotometry. Photoelectrochemical characteristics of CFTSe nanoparticles were also studied, which indicated their potential application in solar energy water splitting.
Polypyrrole (PPy) nanocomposites were prepared using chemical oxidation and were combined with manganese oxide (MnO2) nanoparticles. The PPY-MnO2 nanocomposite was synthesized by integrating PPy nanofibers with varying volume ratio percentages of MnO2 dopant (10, 30, and 50% vol. ratio). The structural features of the PPy and PPy-MnO2 nanocomposite were investigated using X-ray diffraction (XRD). Fourier transfor infrared (FTIR) spectroscopy was used to demonstrate the molecular structures of primary materials and the final product of PPy, MnO2, and PPy- MnO2 nanocomposites. Field Emission Scanning Electron Microscopy (FESEM) showed that the morphology of PPy consisted of a network of nanofibers. Increasing the volume ratios of ma
... Show MoreAzo ligand 11-(4-methoxyphenyl azo)-6-oxo-5,6-dihydro-benzo[4,5] imidazo[1,2-c] quinazoline-9-carboixylic acid was derived from 4-methoxyaniline and 6-oxo-5,6-dihydro-benzo[4,5]imidazo[1,2-c]quinazoline-9-carboxylic acid. The presence of azo dye was identified by elemental analysis and spectroscopic methods (FT-IR and UV-Vis). The compounds formed have been identified by using atomic absorption in flame, FT.IR, UV-Vis spectrometry magnetic susceptibility and conductivity. In order to evaluate the antibacterial efficiency of ligand and its complexes used in this study three species of bacteria were also examined. Ligand and its complexes showed good bacterial efficiencies. From the obtained data, an octahedral geometry was proposed for all p
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