Energy Dispersive X-ray Spectrophotometry Research Articles

HyFlex EDM: superficial features, metallurgical analysis and fatigue resistance of innovative electro discharge machined NiTi rotary instruments.

To evaluate the surface and microstructural alterations of new and used HyFlex EDM prototypes and to test their fatigue resistance. Fifteen HyFlex EDM prototypes were used for in vitro instrumentation of severely curved root canals. Surface and microstructural characteristics of new and used files were compared by ESEM analysis equipped with energy dispersive X-ray spectrophotometry (EDS) and optical metallographic imaging. Usage-induced degradation was assessed. Thirty additional HyFlex EDM prototypes and 20 standard manufactured HyFlex CM files were subjected to cyclic fatigue tests. Time to fracture was recorded, and results were validated using the Kruskal-Wallis test (α-level 0.05). Fatigued files were analysed by ESEM for fractographic evaluation. Surface and microstructural characterization of EDM prototypes revealed the typical spark-machined surface of a NiTi EDM alloy. No fractures were registered during root canal instrumentation. No evident surface alterations and minor degradation were observed between new and used instruments. The metallographic analysis of new and used files disclosed a homogeneous structure, mostly composed of lenticular martensite grains, and some residual austenite. The cyclic fatigue test showed an increase of fatigue resistance up to 700% on the EDM compared to CM files. Spark-machined peculiar surface is the main feature of HyFlex EDM. Low degradation was observed after multiple canal instrumentations. Prototypes exhibited surprising high values of cyclic fatigue resistance and a safe in vitro use in severely curved canals.

Ionic liquid as separation enhancer in thin-layer chromatography of biosurfactants: mutual separation of sodium cholate, sodium deoxycholate and sodium taurocholate

Physiological biosurfactants plays an important role in digestion of lipids and cholesterol also emulsifies fat-soluble vitamins. A new green thin-layer chromatographic system comprising ionic liquid (1-methylimidazolium chloride) impregnated silica gel G and 2-methyl tetrahydrofuran as stationary and mobile phases was found to be most suitable for the separation of ternary mixture of biosurfactants (sodium cholate, sodium deoxycholate and sodium taurocholate). The surface structure and chemical composition of silica gel G modified by impregnation with 1-methylimidazolium chloride were examined with the aid of scanning electron microscopy and energy-dispersive X-ray spectrophotometry, respectively. Compared to plain silica gel, enhanced separation efficiency of ionic liquid impregnated silica gel was observed for the resolution of biosurfactants from their mixture. Chromatographic parameters such as ΔR F, separation factor (α) and resolution (R S) for the separation were calculated. Effect of foreign substances (metal cations, inorganic anions, vitamins, amino acids and non-ionic surfactants as impurities) on the separation of surfactants was also examined. Effects of concentration level of 1-methylimidazolium chloride as impregnant and its substitution by other ionic liquids (1,2,3-trimethylimidazoliummethyl sulphate, 1-ethyl-3-methylimidazolium tetrafluoroborate) were also studied to decide the optimum experimental conditions for better separation possibilities. The limits of detection of sodium cholate, sodium deoxycholate and sodium taurocholate were calculated. A new green thin-layer chromatographic system comprising ionic liquid (1-methylimidazolium chloride) impregnated silica gel G and 2-methyl tetrahydrofuran as stationary and mobile phases provide the most suitable environment for the separation of ternary mixture of biosurfactants.

Chemical Interactions in Reinforced Concrete Exposed at a Tropical Marine Environment

Prediction of concrete structure behavior is complicated by diverse factors, including interaction between elements and concrete compounds, chlorides diffusion through concrete, and compounds formed by corrosion of steel reinforcement. These factors were evaluated in concrete test cylinders exposed to a tropical marine environment since 1993 (during 126 months). Electrochemical, chlorides profile, scanning electron microscope, and energy-dispersive X-ray spectrophotometry analyses were done and results compared. This suite of analytical methods accurately characterized reinforced concrete condition and generated data useful in developing prediction models of corrosion in concrete structures.

Knadungan Unsur Fluor pada Email Gigi TetaP Muda dengan Tumpatan Semen Ionomer Kaca Viskositas Tinggi

The purpose of this study was to determine the fluoride content differences in enamel of immature teeth with Glass Ionomer Cement Fuji IX and Ketac Molar filling.The subject for this study was 21 immature premolars teeth, and each tooth divided into 2 parts. The first part filled with Fuji IX (Fuji IX ART, GC) and the second part filled with Ketac Molar (KetacMolar ART, MI, 3M ESPE), so the samples were 21 Energy Dispersive X-Ray Spectrophotometry analysis of Fuji IX and 21 Energy Dispersive X-Ray Spectrophotometry analysis of Ketac molar. The measurement was done to the fluoride content in enamel of immature teeth using Energy Dispersive X-Ray Spectrophotometry in percentage.This study using t-test, exhibited differences but no significant from the percentage of delta the fluoride content in enamel of immature teeth with Fuji IX and Ketac Molar filling (t=1,953 p > 0.05). DOI: 10.14693/jdi.v15i2.74

Cyclic Fatigue Testing and Metallographic Analysis of Nickel-Titanium Rotary Instruments

Introduction The aim of this study was to compare cyclic fatigue resistance of four nickel-titanium rotary systems and to evaluate their surface, fractographic, and matrix morphology. Methods Four models of endodontic rotary files (EasyShape [Komet/Gebr. Brasseler, Lemgo, Germany], ProTaper [Dentsply Maillefer, Ballaigues, Switzerland], NRT [MANI Inc, Toshigi-Ken, Japan], and AlphaKite [Komet/Gebr. Brasseler]) were subjected to fatigue testing in artificial canals with angle of curvature of 45° and 60° and a radius of curvature of 5 mm until fracture occurred. Nickel-titanium (NiTi) alloy properties were investigated by light microscopy, environmental scanning electron microscopy (ESEM), and energy dispersive x-ray spectrophotometry (EDS). ESEM analysis was conducted on new files to examine surface characteristics and on fractured samples to identify the crack origin and the fractographic features. Results Analysis of variance testing revealed significant differences ( P < .001) among the groups. NRT files had the highest fatigue resistance followed by AlphaKite, EasyShape, and ProTaper. All the new files presented surface imperfections. Fractographic analysis found the crack initiation to originate at the level of surface irregularities. Optical microscope inspection of the NiTi alloy matrix disclosed different-sized nonmetallic inclusions among models. EDS analysis of these inclusions showed that they were composed of carbon and oxygen in addition to nickel and titanium. Under light microscopy, austenitic grains appeared larger near the handle and smaller near the tip in all instruments. Conclusions NRT files presented the longest fatigue life. All samples showed surface irregularities and nonmetallic inclusions. Austenitic grains were smaller near the tip than near the handle. The angle of curvature was confirmed to influence the fatigue life of NiTi instruments.

Virus Silicification under Simulated Hot Spring Conditions

Silicification of organisms in silica-depositing environments can impact both their ecology and their presence in the fossil record. Although microbes have been silicified under laboratory and environmental conditions, viruses have not. Bacteriophage T4 was successfully silicified under laboratory conditions that closely simulated those found in silica-depositing hot springs. Virus morphology was maintained, and a clear elemental signature of phosphorus was detected by energy-dispersive X-ray spectrophotometry (EDS).

Mevinolin enhances osteogenic genes (ALP, type I collagen and osteocalcin), CD44, CD47 and CD51 expression during osteogenic differentiation

Aims In this study, we evaluated the effect of mevinolin on the expressions of osteogenic genes and surface molecules expression during osteogenesis. Main methods D1 cells were cultured in osteogenic differentiation medium (ODM) for 6 days, treated with mevinolin for 2 days, and then subjected to alizarin red S staining, MTT assays, alkaline phosphatase (ALP) activity determinations, energy dispersive X-ray spectrophotometry (EDX), real-time PCR, Western blot, fluorescence microscopy and FACS analysis. Key findings Mevinolin is commonly prescribed and widely used to lower cholesterol levels, and offers an important, effective approach to the treatment of hypercholesterolemia and arteriosclerosis. However, the direct effect of mevinolin on osteogenesis in vitro has not been clarified. ODM has been previously shown to increase the osteoblast differentiation of D1 cells. In the present study, we investigated the expressions of osteogenic genes and surface molecules during osteoblast differentiation induced by mevinolin. We found that the induction of ALP, type I collagen, osteocalcin, CD44, CD47 and CD51 by mevinolin is responsible for the osteoblastic differentiation of D1 cells. Significance Our data show that mevinolin enhances the expressions of proteins and surface molecules related to osteogenesis.

PERBEDAAN KANDUNGAN FLUOR PADA EMAIL GIGI SULUNG YANG DITUMPAT SEMEN IONOMER KACA KONVENSIONAL DAN SEMEN IONOMER KACA VISKOSITAS TINGGI EVALUASI ENERGY DISPERSIVE X-RAY SPECTROPHOTOMETRY (LAPORAN PENELITIAN)

The purpose of this study was to determine the different fluor uptake in enamel of primary teeth filled with Conventional and High Viscosity Glass Ionomer Cement. Samples in this study were 20 non-carious primary maxillary incisors. Samples were divided into 2 groups (10 samples for each group) which were; group 1 filled with Conventional Glass Ionomer Cement and group II filled with High Viscosity. All samples were put in saline solution for 7 days. Each sample was divided into 3 areas in 20 µm 2 square, making 30 data for every group. The different fluor uptake was observed with Energy Dispersive X-Ray Spectrophotometry (EDS) and the results are in graphic . T-test showed significant difference of fluor uptake in enamel of primary teeth between Conventional Glass Ionomer Cement and High Viscosity Glass Ionomer Cement filling (t=2.36, p=0,025). Fluor uptake in enamel of primary teeth filled with High Viscosity Glass Ionomer Cement was much more than Conventional Glass Ionomer Cement.

Kandungan Unsur Fluorida pada Email Gigi Tetap Muda yang Di Tumpat Semen Ionomer Kaca dan Kompomer

The purpose of this study was to determine the fluoride uptake in enamel of young permanent teeth between Glass Ionomer Cement and Compomer filling. The subject for this study was 21 premolar, and each tooth divided into 2 parts. The first part filled with Glass Ionomer Cement (Fuji IX ART,GC), and the second part filled with Compomer (Dyract, Denstsply), so the samples were 21 Energy Dispersive X-Ray Spectrophotometry analysis of Glass Ionomer Cement and 21 Energy Dispersive XRay Spectrophotometry analysis of Compomer. Using t-test the fluoride uptake in the enamel of young permanent teeth with Glass Ionomer Cement and Compomer filling was significantly increased(t=3,705 p=0.001). The increasing of fluoride uptake in the enamel of young permanent teeth with Glass Ionomer Cement filling is more high than Compomer. This study also showed fluoride uptake from Glass Ionomer Cement and Compomer which exhibited in enamel of young permanent teeth was significantly different (t=3,705 p=0.001). Fluoride uptake of Glass Ionomer Cement filling in enamel of immature teeth was much more compare to Compomer. DOI: 10.14693/jdi.v15i3.28

Alendronate Enhances Osteogenic Differentiation of Bone Marrow Stromal Cells: A Preliminary Study

Alendronate inhibits osteoclastic activity. However, some studies suggest alendronate also has effects on osteoblast activity. We hypothesized alendronate would enhance osteoblastic differentiation without causing cytotoxicity of the osteoblasts. We evaluated the effect of alendronate on the osteogenic differentiation of mouse mesenchymal stem cells. D1 cells (multipotent mouse mesenchymal stem cells) were cultured in osteogenic differentiation medium for 7 days and then treated with alendronate for 2 days before being subjected to various tests using MTT assays, Alizarin Red, enzyme-linked immunosorbent assay, energy-dispersive xray spectrophotometry, reverse transcriptase-polymerase chain reaction, confocal microscopy, and flow cytometric analysis. D1 cells differentiated into osteoblasts in the presence of osteogenic differentiation medium as confirmed by positive Alizarin Red S staining, increased alkaline phosphatase activity and osteocalcin mRNA expression, a calcium peak by energy-dispersive xray spectrophotometry, and by positive immunofluorescence staining against CD44. Osteogenic differentiation was enhanced after treatment with alendronate as confirmed by Alizarin Red S staining, elevated alkaline phosphatase activity and osteocalcin mRNA expression, a greater calcium peak by energy-dispersive xray spectrophotometry, and by immunofluorescence staining against CD44 by flow cytometric analysis. These data suggest alendronate enhances osteogenic differentiation when treated with mouse mesenchymal stem cells in osteogenic differentiation medium.

PERBEDAAN PENYERAPAN FLUOR PADA EMAIL GIGI SULUNG ANTARA TUMPATAN SEMEN IONOMER KACA DAN KOMPOMER

The purpose of this study was to determine fluor uptake difference in enamel of primary teeth between Glass Ionomer Cement and Compomer filling. The sample was 30 maxillary first incisors divided into 2 groups. Each group consisted of 15 teeth. The first group was filled with Glass Ionomer Cement (Fuji IX ART, GC) and the second group was filled with Compomer (Dyract, Dentsply). The measurement was in percentage, using Energy Dispersive X-Ray Spectrophotometry. T test exhibited significant differenc of fluor uptake in enamel of primary teeth between Glass Ionomer and Compomer gilling (t=1.1, p= 0.0001). Fluor uptake of Glass Ionomer Cemeng filling in enamel of priary teeth much more compare to Compomer filling.

Carousel stage for multisample microanalysis by scanning electron microscopy/energy dispersive x-ray spectrophotometry

Multielement microanalyses of multiple samples by scanning electron microscopy coupled with energy dispersive x-ray spectrophotometry is facilitated by the construction of a carousel stage that allows multiple samples and standards to be accessible to the electron beam.