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Bismuth silicate

Viktor A Vorozhtcov, Valentina L Stolyarova, Sergey I Lopatin, Sergey M Shugurov, Andrey L Shilov, Vladimir F Sapega
RATIONALE: The Bi2 O3 -P2 O5 -SiO2 system possesses a number of valuable properties that may be of use for various practical applications, both for obtaining new materials e.g. optical fibers and for replacing systems based on toxic lead silicate. Information on vaporization processes and thermodynamic properties obtained in the present study will be useful for the development of synthesis methods and approaches for modeling the thermodynamic properties of materials based on this system...
October 14, 2016: Rapid Communications in Mass Spectrometry: RCM
Liudmila D Iskhakova, Filipp O Milovich, Valery M Mashinsky, Alexander S Zlenko, Sergey E Borisovsky, Evgeny M Dianov
The nature of nanocrystalline inclusions and dopant distribution in bismuth-doped silicate fibers and preforms are studied by scanning and transmission electron microscopy, and energy and wavelength-dispersive X-ray microanalysis. The core compositions are Bi:SiO2, Bi:Al2O3-SiO2, Bi:GeO2-SiO2, Bi:Al2O3-GeO2-SiO2, and Bi:P2O5-Al2O3-GeO2-SiO2. Nanocrystals of metallic Bi, Bi2O3, SiO2, GeO2, and Bi4(GeO4)3 are observed in these glasses. These inclusions can be the reason for the background optical loss in bismuth-doped optical fibers...
September 26, 2016: Microscopy and Microanalysis
Linling Tan, Liping Wang, Mingying Peng, Shanhui Xu, Qinyuan Zhang
For application of bismuth laser glasses in either fiber amplifier or laser, their performance stability in long run should be understood especially in extreme conditions. However, so far, there are few reports on it. Here, we found, after the cycle experiments on heating and cooling, that the proper increase of lithium content in lithium tantalum silicate laser glass can lead to unusual anti-thermal degradation of bismuth NIR luminescence, which completely differs from the scenario in germanate glass. FTIR, <sup>29</sup>Si MAS NMR spectra, absorption and dynamic photoluminescence spectra are employed to unravel how this happens...
August 8, 2016: Optics Express
V Thomas, R G S Sofin, M Allen, H Thomas, P R Biju, G Jose, N V Unnikrishnan
Samarium doped sodium bismuth silicate glass was synthesized using the melt quenching method. Detailed optical spectroscopic studies of the glassy material were carried out in the UV-Vis-NIR spectral range. Using the optical absorption spectra Judd-Ofelt (JO) parameters are derived. The calculated values of the JO parameters are utilized in evaluating the various radiative parameters such as electric dipole line strengths (Sed), radiative transition probabilities (Arad), radiative lifetimes (τrad), fluorescence branching ratios (β) and the integrated absorption cross- sections (σa) for stimulated emission from various excited states of Sm(3+)‡ ion...
January 15, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Juliane Maria Guerreiro-Tanomaru, Fernando Antonio Vázquez-García, Roberta Bosso-Martelo, Maria Inês Basso Bernardi, Gisele Faria, Mario Tanomaru
OBJECTIVE: Mineral Trioxide Aggregate (MTA) is a calcium silicate cement composed of Portland cement (PC) and bismuth oxide. Hydroxyapatite has been incorporated to enhance mechanical and biological properties of dental materials. This study evaluated physicochemical and mechanical properties and antibiofilm activity of MTA and PC associated with zirconium oxide (ZrO2) and hydroxyapatite nanoparticles (HAn). MATERIAL AND METHODS: White MTA (Angelus, Brazil); PC (70%)+ZrO2 (30%); PC (60%)+ZrO2 (30%)+HAn (10%); PC (50%)+ZrO2 (30%)+HAn (20%) were evaluated...
May 2016: Journal of Applied Oral Science: Revista FOB
Sergei V Firstov, Sergey V Alyshev, Konstantin E Riumkin, Vladimir F Khopin, Alexey N Guryanov, Mikhail A Melkumov, Evgeny M Dianov
It is now almost twenty-five years since the first Erbium-Doped Fiber Amplifier (EDFA) was demonstrated. Currently, the EDFA is one of the most important elements widely used in different kinds of fiber-optic communication systems. However, driven by a constantly increasing demand, the network traffic, growing exponentially over decades, will lead to the overload of these systems ("capacity crunch") because the operation of the EDFA is limited to a spectral region of 1530-1610 nm. It will require a search for new technologies and, in this respect, the development of optical amplifiers for new spectral regions can be a promising approach...
2016: Scientific Reports
Christian A Dettwiler, Mirella Walter, Lucia K Zaugg, Patrik Lenherr, Roland Weiger, Gabriel Krastl
BACKGROUND/AIMS: Traumatized teeth requiring endodontic intervention may discolor as a result of the treatment performed. Thus, the aim was to investigate the discoloration potential of different endodontic cements, dressings, and irrigants used in dental traumatology. MATERIALS AND METHODS: Cylindrical cavities were prepared in 330 bovine enamel-dentine blocks (10 × 10 × 3.5 mm), leaving 2 mm of enamel and dentine on the labial side. The specimens were randomly assigned to 22 groups (n = 15)...
May 18, 2016: Dental Traumatology: Official Publication of International Association for Dental Traumatology
Gonggong Lu, Kehui Qiu, Junfeng Li, Wentao Zhang, Xiqiang Yuan
A series of novel red-emitting Sm(3) (+) -doped bismuth silicate phosphors, Bi4 Si3 O12 :xSm(3) (+) (0.01 ≤ x ≤ 0.06), were prepared via the sol-gel route. The phase of the synthesized samples calcinated at 800 °C is isostructural with Bi4 Si3 O12 according to X-ray diffraction results. Under excitation with 405 nm light, some typical peaks of Sm(3) (+) ions centered at 566, 609, 655 and 715 nm are found in the emission spectra of the Sm(3) (+) -doped Bi4 Si3 O12 phosphors. The strongest peak located at 609 nm is due to (4) G5 /2 -(6) H7 /2 transition of Sm(3) (+) ...
May 5, 2016: Luminescence: the Journal of Biological and Chemical Luminescence
Shahbaz Khan, Muhammad Kaleem, Muhammad Amber Fareed, Amir Habib, Kefi Iqbal, Ayesha Aslam, Shahab Ud Din
The purpose of this study was to investigate the chemical composition and particle morphology of white mineral trioxide aggregate (WMTA) and two white Portland cements (CEM 1 and CEM 2). Compositional analysis was performed by energy dispersive X-ray spectroscopy, X-ray fluorescence spectrometry and X-ray diffraction whereas, morphological characteristics were analyzed by scanning electron microscope and Laser scattering particle size distribution analyzer. The elemental composition of WMTA, CEM 1 and CEM 2 were similar except for the presence of higher amounts of bismuth in WMTA...
2016: Dental Materials Journal
Li-na Niu, Devon Watson, Kyle Thames, Carolyn M Primus, Brian E Bergeron, Kai Jiao, Eduardo A Bortoluzzi, Christopher W Cutler, Ji-hua Chen, David H Pashley, Franklin R Tay
Discoloration-resistant calcium aluminosilicate cement has been formulated to overcome the timely problem of tooth discoloration reported in the clinical application of bismuth oxide-containing hydraulic cements. The present study examined the effects of this experimental cement (Quick-Set2) on the viability and proliferation of human dental pulp stem cells (hDPSCs) by comparing the cellular responses with commercially available calcium silicate cement (white mineral trioxide aggregate; WMTA) after different aging periods...
November 30, 2015: Scientific Reports
Ghoulipour Vanik, Hassankhani-Majd Zahra
A simple and sensitive method for the separation and determination of isoproterenol from other doping drugs has been developed on thin layers of bismuth silicate, a synthetic inorganic ion exchanger as adsorbent in thin layer chromatography (TLC). A mixture of methanol and 0.1 mol/L formic acid (3:7, v/v) was employed as the mobile phase. The development time was 32 min. The quantitative measurement were performed with a Camag TLC Scanner-3 at wavelength (λ) of 410 nm. The isoproterenol recovery in this procedure was 98...
June 2015: Se Pu, Chinese Journal of Chromatography
M Xuereb, F Sorrentino, D Damidot, Josette Camilleri
OBJECTIVES: All implants, bone and endodontic cements need to be sufficiently radiopaque to be able to be distinguished from neighbouring anatomical structures post-operatively. For this purpose, radiopacifying materials are added to the cements to render them sufficiently radiopaque. Bismuth oxide has been quite a popular choice of radiopacifier in endodontic materials. It has been shown to cause dental discoloration. The aim of this study was to develop, characterize and assess the properties of tricalcium silicate cement with alternative radiopacifiers, which are either inter-ground or sintered to the tricalcium silicate cement...
June 2016: Clinical Oral Investigations
A T Moinzadeh, L Jongsma, D de Groot-Kuin, R Cristescu, N Neirynck, J Camilleri
Hydraulic Calcium Silicate Cements (HCSCs) constitute a group of materials that have become increasingly popular in endodontics since the introduction of Mineral Trioxide Aggregate (MTA) in the 1990s. MTA is Portland cement to which bismuth oxide has been added to increase its radiopacity. The most important property of MTA is its capacity to set in water or a humid environment. However, MTA also has important limitations, for example, it's difficult to work with and can discolour teeth. Recently, numerous products based on HCSC chemistry, which can be considered as modifications of MTA intended to reduce its limitations, have become available on the market...
July 2015: Nederlands Tijdschrift Voor Tandheelkunde
Daehee Seol, Hiroki Taniguchi, Jae-Yeol Hwang, Mitsuru Itoh, Hyunjung Shin, Sung Wng Kim, Yunseok Kim
Bismuth silicate (Bi2SiO5) was recently suggested as a potential silicate based lead-free ferroelectric material. Here, we show the existence of ferroelectricity and explore the strong anisotropy of local ferroelectricity using piezoresponse force microscopy (PFM). Domain structures are reconstructed using angle-resolved PFM. Furthermore, piezoresponse hysteresis loops and piezoelectric coefficients are spatially investigated at the nanoscale. The obtained results confirm the existence of ferroelectricity with strong c-axis polarization...
July 21, 2015: Nanoscale
Roberta Bosso-Martelo, Juliane M Guerreiro-Tanomaru, Raqueli Viapiana, Fabio Luiz C Berbert, Marco Antonio Hungaro Duarte, Mário Tanomaru-Filho
OBJECTIVES: The objective of this paper was to evaluate the physicochemical properties of calcium silicate cements with different chemical compositions, associated with radiopacifying agents. MATERIALS AND METHODS: Mineral trioxide aggregate (MTA) Angelus, calcium silicate cement with additives (CSC), and resinous calcium silicate cement (CSCR) were evaluated, with the addition of the following radiopacifiers: microparticles (micro) or nanoparticles (nano) of zirconium oxide (ZrO(2)), niobium oxide (Nb(2)O(5)), bismuth oxide (Bi(2)O(3)), or calcium tungstate (CaWO(4))...
January 2016: Clinical Oral Investigations
Kyoung-A Kim, Yeon-Mi Yang, Young-Sun Kwon, Yun-Chan Hwang, Mi-Kyung Yu, Kyung-San Min
A fast-setting calcium-silicate cement (Endocem) was introduced in the field of dentistry for use in vital pulp therapy. Similar to mineral trioxide aggregate (MTA), it contains bismuth oxide to provide radiopacity. Recently, another product, EndocemZr, which contains zirconium oxide (ZrO2) as a radiopacifier, was developed by the same company. In this study, the biological/odontogenic effects of EndocemZr were investigated in human primary dental pulp cells (hpDPCs) in vitro and on capped rat teeth in vivo...
2015: Dental Materials Journal
Cangul Keskin, Ebru Ozsezer Demiryurek, Taha Ozyurek
INTRODUCTION: Mineral trioxide aggregate (MTA) has been reported to cause tooth discoloration when applied in the esthetic zone. A previous study has shown discoloration of MTA in contact with root canal irrigation solutions. Moreover, there are limited data on color stability of novel calcium silicate-based materials. This study aimed to evaluate color changes of 4 calcium silicate-based materials in contact with different irrigation solutions. METHODS: ProRoot white MTA (Dentsply Tulsa Dental, Johnson City, TN), white MTA Angelus (Angelus Solucoes Odontologicas, Londrina, Brazil), Biodentine (Septodont, Saint Maur des Fosses, France), and BioAggregate (Innovative Bioceramix, Vancouver, BC, Canada) samples were assessed...
March 2015: Journal of Endodontics
Mohammad Ali Saghiri, James L Gutmann, Jafar Orangi, Armen Asatourian, Nader Sheibani
INTRODUCTION: The aim of this study was to evaluate the impact of radiopaque additive, bismuth oxide, particle size on the physical properties, and radiopacity of tricalcium silicate-based cements. METHODS: Six types of tricalcium silicate cement (CSC) including CSC without bismuth oxide, CSC + 10% (wt%) regular bismuth oxide (particle size 10 μm), CSC + 20% regular bismuth oxide (simulating white mineral trioxide aggregate [WMTA]) as a control, CSC + 10% nano bismuth oxide (particle size 50-80 nm), CSC + 20% nano-size bismuth oxide, and nano WMTA (a nano modification of WMTA comprising nanoparticles in the range of 40-100 nm) were prepared...
February 2015: Journal of Endodontics
H M Setbon, J Devaux, A Iserentant, G Leloup, J G Leprince
OBJECTIVES: New commercial tricalcium silicate based cements were elaborated to improve handling properties and setting time. The goals of the present work were: (i) to determine the composition of the new injectable and/or fast setting calcium silicate based cements, and (ii) to investigate the impact of the differences in composition on their setting kinetics. METHODS: The materials considered were Angelus MTA™, Biodentine™, MM-MTA™, MTA-Caps™, and ProRoot MTA™ as control...
December 2014: Dental Materials: Official Publication of the Academy of Dental Materials
Z S Madani, S A Sefidgar, A Rashed Mohasel, E Zabihi, A Mesgarani, A Bijani, S S Miri
AIM: Even after a complete root canal therapy, reinfection may occur as a result of incomplete seal and activation of residual bacteria. Thus, antimicrobial activity is an important characteristic of root canal sealers. MTA Fillapex is a newly developed MTA-based sealer. It has been subjected to various studies evaluating its physical and chemical properties. In this study, we aimed to compare the antimicrobial activity of this sealer to the commonly known widely accepted sealer, AH26...
July 2014: Minerva Stomatologica
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