Search results for "resin"
showing 10 items of 385 documents
Beneficios de la terapia de resincronización cardíaca en pacientes con severa disfunción y dilatación ventricular izquierda en la insuficiencia cardi…
2015
Beneficios de la terapia de resincronización cardíaca en pacientes con severa disfunción y dilatación ventricular izquierda en la insuficiencia cardiaca leve respecto a la avanzada. Hipótesis: Comparar los beneficios ecocardiográficos, funcionales y pronósticos de la terapia de resincronización cardiaca (TRC) en el grupo con insuficiencia cardiaca (IC) leve (grupo 1) respecto a la IC avanzada (grupo 2). Material y métodos: El número total de pacientes fue de 98, todos portadores de un desfibrilador-resincronizador (grupo 1=49; grupo 2=49). Los objetivos fueron: 1) Ecocardiográficos: mejora del diámetro telediastólico/telesistólico (DTDVI/DTSVI) (reducción ? 5 mm), de la fracción de eyección…
Resistencia erosiva de composites dentales directos e indirectos CAD/CAM
2020
Resistencia erosiva de composite directos e indirectos CAD/ CAM El propósito de este estudio in vitro es investigar la resistencia erosiva en las diferentes propiedades de los composites tipo directo e indirecto CAD/CAM. Se emplearon seis composites, tres de tipo directo FILTEK Supreme XTE, BRILLIANT EverGlow, GrandioSo y tres indirectas para CAD/CAM Lava Ultimate, BRILLIANT Crios, Grandio Blocs fueron empleadas. Se dividieron aleatoriamente, en un grupo control y otro con jugo gástrico simulado. Se analizó la microdureza Vickers, Resistencia a la flexión de tres puntos ( Módulo de Weibull), desgaste y la topografía superficial con un microscopio de fuerza atómica (AFM). Los datos fueron an…
Microleakage and shear bond strength of orthodontc brackets bonded to hypomineralized enamel following different surface preparations
2014
Objectives: This study investigated the effects of several conditioning methods on shear bond strength (SBS) and microleakage of orthodontic brackets bonded to demineralized enamel. Study Design: One hundred premolars were selected and immersed in a cariogenic solution for 12 weeks. The teeth were randomly assigned into 5 groups. In groups 1 and 2, the teeth underwent acid etching for 30 and 120 seconds, respectively. In group 3, a combination of laser and acid etching was employed. A self-etch primer (SEP) was applied in group 4 and in group 5, the teeth were exposed to acidulated phosphate fluoride (APF) for 4 minutes before etching. After bracket bonding, the teeth were immersed in methy…
Influence of artificial aging and ZrO2 nanoparticle-reinforced repair resin on the denture repair strength
2019
Background The purpose of this study was to evaluate the effect of aging process on the tensile strength (TS) of repaired acrylic denture base using ZrO2 nanoparticles (nano-ZrO2)-reinforced autopolymerized resin. Material and Methods A total of 240 heat-polymerized acrylic resin specimens (n=10) were prepared and sectioned creating 2 mm-repair-gap. Autopolymerized acrylic resin, pure and modified with 2.5, 5, and 7.5wt% nano-ZrO2 were used for specimens repair. TS of repaired specimens were measured using the universal testing machine after water immersion at 37oC for 2, 7 and 30 days. At each time interval, half the immersed specimens underwent thermo-cycling aging process (5000 cycles at…
Gas chromatography-mass spectrometry characterization of the varnish and glue of an ancient 18th century double bass.
2007
A GC–MS investigation is conducted on the double bass “Panormus”, property of Conservatorio di Musica “Vincenzo Bellini” in Palermo. The most important components of the varnish (fatty acids) and of the glue (proteinaceous amino acids), with which the musical instrument was treated in the past, are determined. The analyses are carried out by prior derivatization of fatty acids by acidic methanol and of amino acids by acidic methanol and trifluoroacetic anhydride (TFAA). Analytes identification is achieved by direct comparison with several reference materials and the use of a digitized library.
FIA-fluorimetric determination of thiamine.
1990
A flow injection-fluorimetric determination of thiamine is reported. The procedure is based on the oxidation of the analyte with potassium hexacyanoferrate(III) immobilized on an anionic exchange resin; the fluorescence is monitored in aqueous basic solution. Concentrations of the vitamin of 0.1-4 ppm have been determined; the relative standard deviation was 1.8%. The injection rate was 28 samples/h. The influence of other substances and the determination of the drug in a pharmaceutical formulation are also reported.
HPLC determination of volatile phenols in wines
1993
An alternative to the traditional solvent extraction method used to extract and rapidly quantify ethyl-and vinylphenol and ethyl-and vinylgaiacol from wine is presented. The method is based on retention of volatile phenols on adsorbants. Among the tested resins, the most efficient, AG 2-X8 (anion exchange resin), worked as well with a synthetic solution as with wines. The percolation of clarified wine adjusted to pH 9 on this resin permits, in particular, the elimination of organic acids. Phenols are not eluted after rinsing the column with 1N HCl, but are eluted with methanol after this treatment. Good recovery (91 %) and good repeatability are observed. The eluate is directly analysed by …
Color stability of Bulk-Fill composite restorations
2020
Made available in DSpace on 2022-04-28T19:29:50Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-11-01 Background: The color stability of the composite resin is an important property that influences its clinical longevity, which remains an inherent challenge to the material. Thus, the purpose of this study was to evaluate the color stability of bulk-fill resins when exposed to dye. Material and Methods: Cavities were prepared in 80 bovine incisors, which were randomly assigned into 4 groups (n = 20) according with the resin composite used: P60 (Control Group - Filtek P60, 3M/ESPE), FP (Filtek Bulk-Fill Posterior, 3M/ESPE), SDR (SDR, Dentsply) and FF (Filtek Bulk Fill Flow, 3M/ESPE). A…
Hochleistungsfl�ssigchromatographische Bestimmung von organischen S�uren, Zuckern, Glycerin und Alkohol im Wein an einer Kationenaustauschers�ule
1985
Mit der HPLC ist es moglich, die wichtigsten Bestandteile von Wein (Ethanol, Glycerin, Glucose, Fructose, Tartrat, Malat, Lactat, Succinat, Acetat und Citrat) in einem Lauf innerhalb von 25 min zu trennen und quantitativ zu bestimmen. Als stationare Phase dient der Kationenaustauscher HPX 87 H und als mobile Phase verdunnte Schwefelsaure. Die Untersuchungsergebnisse an einigen Weinen werden dargestellt. Es besteht eine gute Ubereinstimmung zwischen den Analysenergebnissen der HPLC und herkommlichen Methoden.[/p]
Effect of thermocycling with or without 1 year of water storage on retentive strengths of luting cements for zirconia crowns
2015
Abstract Statement of problem Bond stability between zirconia crowns and luting cement and between cement and dentin is a main concern; however, only limited evidence is available as to its longevity. Purpose The purpose of this in vitro study was to measure the retentive strengths of 7 self-adhesive cements (RelyX Unicem Aplicap, RelyX Unicem Clicker, RelyX Unicem 2 Automix, iCEM, Maxcem Elite, Bifix SE, SpeedCem), 2 adhesive cements with self-etch primers (Panavia 21, SEcure), 1 glass ionomer cement (Ketac Cem), 1 resin-modified glass ionomer cement (Meron Plus), and 1 zinc phosphate cement for luting zirconia crowns (LAVA) to extracted teeth after thermocycling with or without 1 year of …