Background: The bond strength of the root canal sealers to dentin is very important property for maintaining the integrity and the seal of root canal filling. The aim of this study was to evaluate and compare the push-out bond strength of root filled with total fill Bioceramic, AH Plus and Gutta-flow®2 sealers using GuttaFusion®obturation system versus single cone obturation technique. Materials and method: sixty of mandibular premolars teeth with straight roots were used in this study, these roots were instrumented using Reciproc system, instrumentation were done with copious irrigation of 3 mL 5.25% sodium hypochlorite solution (NaOCl) during all the steps of preparation, and smear layer will be removed with 1 ml of 17% EDTA kept in the canal for 1 min, roots were randomly divided into two groups according to the obturation technique (thirty teeth for each group): Group I: Single Reciproc Gutta percha cone obturation technique, Group II: Gutta fusion obturation technique, then each group divided into three subgroup according to the type of sealer, AH subgroup: AH Plus sealer, BC subgroup: bioceramic sealer and GF subgroup: Gutta flow 2 sealer. The roots then stored in moist environment at 37°C for one week, the roots were embedded in clear acrylic resin and each root sectioned into three levels apical, middle and cervical. The bond strength was measured using computerized universal testing machine each section fixed in the machine so that the load applied from apical to cervical direction at 0.5mm/min. speed and the computer show the higher bond force before dislodgment of the filling material. These forces were divided by the surface area to obtain the bond strength in MPa. Results: Statistical analysis was performed and the result showed a highly significant differences between the three types of sealers when the same obturation technique were used, also there is highly significant differences between two groups with two different obturation technique. Conclusion: This study showed that the push out bond strength of AH plus sealer was higher than bioceramic sealer and Gutta flow 2 sealer respectively when the same obturation technique was used. The push out bond strength was affected by the obturation technique and Gutta fusion obturation technique showed higher bond strength than single cone obturation technique when the same type of sealer was used.
This study was designed to evaluate the effect of anesthesia on thyroid hormones (T3, T4, rT3), thyrotropin(TSH), and cortisol levels in patients undergoing major urological surgery. The study included fifty patients scheduled for elective major urological surgery where 70% of the patients underwent general anesthesia, while30% underwent regional anesthesia. All patients were in stable control general conditions. The study showed that the thyroid hormones, thyrotropin and cortisol levels were affected with general anesthesia more than regional. The levels of these hormones responded to anesthetics and surgical stresses. This response was thought to be mainly mediated by afferent neurogenic impulses from the area of injury. Therefore, ab
... Show MoreAn experimental investigation has been made to study the influence of using v-corrugated aluminum fin on heat transfer coefficient and heat dissipation in a heat sink. The geometry of fin is changed to investigate their performance. 27 circular perforations with 1 cm diameter were made. The holes designed into two ways, inline arrangement and staggered in the corrugated edges arrangement. The experiments were done in enclosure space under natural convection. Three different voltages supplied to the heat sink to study their effects on the fins performance. All the studied cases are compared with v-corrugated smooth solid fin. Each experiment was repeated two times to reduce the error and the data recorded after reaching t
... Show MoreAccording to the famous saying of the medieval physician Paracelsus, "There is no substance without poison. Only the dose determines the extent of the toxic effect." Here, the effect of monosodium glutamate (MSG) on human health and the risks to the health of its frequent use in the short term was addressed and the long term was evaluated according to the studies of several researchers specializing in this regard. Monosodium glutamate (MSG) is known as one of the most popular food additives that classified as a flavor enhancer. Parts of the evidence were reviewed from the literature explaining its effect on immune system cells in addition to metabolic disorders by exposing individuals to obesity and what is known as metabolic syndrome, as w
... Show MoreThe effect of heat treatment using different annealing temperatures on optical properties of bulk heterojunction blend (BHJ) Alq3: C60 thin films which are fabricated by the spin coating technique were investigated in this study. The films have been coated on a glass substrate with speed of 2000 rpm for one min and treated with different annealing temperature (373, 423 and 473) K under vacuum. The optical properties and the chemical bonds structure of blends as-deposited and heat treated have been studied by UV-Vis spectroscopic and Fourier Transform-Infra Red (FTIR) measurements respectively. The results of UV visible show that the optical energy gap decreasing with increasing the annealing temperature for the ratio (100:1) while decrea
... Show MoreElectrical Discharge Machining (EDM) is a widespread Nontraditional Machining (NTM) processes for manufacturing of a complicated geometry or very hard metals parts that are difficult to machine by traditional machining operations. Electrical discharge machining is a material removal (MR) process characterized by using electrical discharge erosion. This paper discusses the optimal parameters of EDM on high-speed steel (HSS) AISI M2 as a workpiece using copper and brass as an electrode. The input parameters used for experimental work are current (10, 24 and 42 A), pulse on time (100, 150 and 200 µs), and pulse off time (4, 12 and 25 µs) that have effect on the material removal rate (MRR), electrode wear rate (EWR) and wear ratio (WR). A
... Show MoreBackground: The aims of this study were to evaluate the effect of implant site preparation in low-density bone using osseodensification method in terms of implant stability changes during the osseous healing period and peri-implant bone density using CBCT. Material and methods: This prospective observational clinical study included 24 patients who received 46 dental implants that were installed in low-density bone using the osseodensification method. CBCT was used to measure the bone density pre- and postoperatively and implant stability was measured using Periotest® immediately after implant insertion and then after 6 weeks and 12 weeks postoperatively. The data were analyzed using paired t-test and the probability value <0.05 was conside
... Show MoreThis work studies with produce of light fuel fractions of gasoline, kerosene and gas oil from treatment of residual matter that will be obtained from the solvent extraction process as by product from refined lubricate to improve oil viscosity index in any petroleum refinery. The percentage of this byproduct is approximately 10% according to all feed (crude oil) in the petroleum refinery process. The objective of this research is to study the effect of the residence time parameter on the thermal cracking process of the byproduct feed at a constant temperature, (400 °C). The first step of this treatment is the thermal cracking of this byproduct material by a constructed batch reactor occupied with control device at a selective range of re
... Show MoreThis work reports the study of heat treatment effect on the structural, morphological, optical and electrical properties of poly [3-hexylthiophene] and its blend with [6,6]-phenyl C61 butyric acid methyl ester ( P3HT:PC61BM). X-ray diffraction (XRD) measurements show that the crystallinity of the films increased with annealing. The evaluation of surface roughness and morphology was investigated using atomic force microscope (AFM), and field emission scanning microscope(FESEM). The optical properties were emphasized a strong optical absorption of P3HT compared with the blend. Hall effect measurement was used to study the electrical properties which revealed there is an increase in the electrical conductivity and Hall mobility of th
... Show MoreA simple low-cost approach at various exposure times was utilized to generate cold plasma in the aim to fabricate AuNPs. UV-Visible spectra and X-ray diffraction were used to characterize the nanoparticles (XRD). Surface Plasmon resonance was observed in the synthesized AuNPs at 530, 540, and 533 nm. For all samples, the patterns of XRD show very intensive peaks implying the fcc crystalline structure of AuNPs. The average crystallite size of AuNPs is ranging between 20-30 nm. The observation of morphology by FESEM revealed the spherical formation of AuNPs. Doses of 100 and 200 ppm of AuNPs were adapted to investigate their effect on the blood-mixture with and without a 20-second of cold plasma exposure. The WBC components in the blood
... Show MoreSystemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by the production of autoantibodies against nuclear antigens and a systemic inflammation that can damage a broad spectrum of organs. SLE patients suffer from a wide variety of symptoms, which can affect virtually almost any tissue. As lupus is difficult to diagnose, the worldwide prevalence of SLE can only be roughly estimated to range from 10 and 200 cases per 100,000 individuals with dramatic differences depending on gender, ethnicity, and location. Although the treatment of this disease has been significantly ameliorated by new therapies, improved conventional drug therapy options, and a trained expert eye, the underlying pathogenesis of lupus still
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