Bismuth silicate

Certain nanomaterials can filter and alter unwanted compounds due to a high surface area, surface reactivity, and microporous structure. Herein, γ-Bi2 MoO6 particles are synthesized via a colloidal hydrothermal approach using organically modified Laponite as a template. This organically modified Laponite interlayer serves as a template promoting the growth of the bismuth molybdate crystals in the [010] direction to result in hybrid Laponite-Bi2 MoO6 particles terminating predominantly in the {100} crystal facets...

This work reported an efficient catalyst to reduce the organic pollutants by using an energetic periodic mesoporous organosilica (PMOS) supported with Bismuth (Bi-PMOS) and Cerium (Ce-PMOS). PMOS-support was designed through co-condensation of sodium silicate and 3-methacryloxypropyl trimethoxysilane on polysorbate templates. The resultant PMOSs were fabricated with bismuth and cerium oxides to formulate Bi-PMOS and Ce-PMOS, respectively. These materials showed photo-degradations of methylene blue (MB, 74.7% and 41...

Mineral trioxide aggregate (MTA) is an ideal yet costly endodontic sealer material. Tricalcium silicate-white Portland cement (TS-WPC) seems to have similar characteristics to those of MTA. This work aims to characterize a modified TS-WPC and evaluate its antibacterial properties as a potential endodontic sealer material. The modified TS-WPC was synthesized from a 4:1 mixture of sterilized Indocement TS-WPC and bismuth trioxide using a simple solution method with 99.9% isopropanol. The mixture was stirred until it was homogenous, centrifuged, and dried...

In this paper, nanocrystalline silicate-substituted hydroxyapatites (nSi-HAps) codoped with Eu3+ were functionalized with Bi3+ ions. Biomaterials were synthesized using a microwave-assisted hydrothermal method and heat-treated at 700 °C. The concentration of Eu3+ ions was established at 1 mol %, and the concentration of Bi3+ was in the range of 0.5-2 mol %. The physicochemical properties of the obtained biomaterials were determined using previously established methods, including X-ray powder diffraction, scanning electron microscopy techniques, and IR spectroscopy...

The aim of this article was to investigate the unknown radiopacity performances of OrthoMTA and RetroMTA via means of a contemporary image analyzing methods and energy dispersive X-ray spectroscopy. Three commercial hydraulic calcium silicate-based cements and a calcium hydroxide-based paste were used. Pure-grade zirconium oxide, bismuth oxide, zinc oxide, barium sulfate, and calcium hydroxide were as references. An energy-dispersive X-ray spectroscopy instrument was used for the elemental analysis. Radiographic image data was obtained according to the International Organization for Standardization 6876-2012 specifications...

Bismuth-based (nano)materials have been attracting increasing interest due to appealing properties such as high refractive indexes, intrinsic opacity, and structural distortions due to the stereochemistry of 6s2 lone pair electrons of Bi3+ . However, the control over specific phases and strategies able to stabilize uniform bismuth-based (nano)materials is still a challenge. In this study, we employed the ability of bismuth to lower the melting point of silica to introduce a new synthetic approach able to confine the growth of bismuth-oxide-based materials into nanostructures...

Bismuth(III) oxide is included as a radio-opacifier in dental materials, including hydraulic silicate cements, the material of choice for several endodontic procedures. It has been implicated in tooth discoloration after contact with endodontic irrigants, in particular NaOCl solution, To date, there has been no work on the chemistry: all reports have been of clinical findings only. The purpose now was to report the reactions leading to colour change from Bi2O3 in contact with solutions used in routine endodontic practice...

The local structure, d-d transition band as well as spin Hamiltonian parameters (SHPs) are theoretically studied for the V4+ probe in 10Na2 O-30PbO-10Bi2 O3 -(50-x)SiO2 (NPBS) glass ceramics containing V2 O5 dopant with various concentration x (0 ≤ x ≤ 5 mol %) by using the perturbation formulas of the SHPs for tetragonally compressed octahedral 3d1 clusters. The first decreasing (or increasing) and then increasing (or decreasing) d-d transition band (= 10 Dq ) and hyperfine structure constants A// and A⊥ (or g factors g// and g⊥ ) with x can be suitably simulated with the similarly varying Fourier type concentration functions of cubic field parameter Dq , covalence factor N, core polarization constant κ and reduction factor H (or relative tetragonal compression ratio ρ), with the minima (or maxima) at the middle concentration x = 3 mol %, respectively...

OBJECTIVES: To evaluate a new material containing tantalum oxide as an alternative radiopacifier, and a water-based gel for hydration, in comparison with two calcium silicate-based cement: ProRoot MTA and Biodentine. MATERIALS AND METHODS: ProRoot MTA (Dentsply), Biodentine (Septodont), and a new hydraulic calcium silicate cement White-MTAFlow (Ultradent) (in 'thin' consistency) were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS)...

In recent years, the preference for using lead-free radiation protection shields has increased because of concerns regarding lead poisoning and leakage. In medical and research laboratories, glass shields are preferred because of their transparency. In this study, various glass shields were examined and compared based on the international standards. One commercially available lead-based shield, four recently studied shields, and three new lead-free shields were considered, and their shielding factors were calculated...

Tricalcium silicate-based cement are materials used in reparative and regenerative procedures in endodontics. A recently proposed formulation aimed to enhance handling during clinical use with a versatile material applicable by syringe. Although, the use of bismuth oxide as radiopacifier and grey raw powder are drawbacks considering aesthetics. Objectives Evaluate physicochemical, biological, and antimicrobial properties of Grey-MTAFlow (Ultradent) and assess whether the addition of zinc oxide (ZnO) prevents dentinal discoloration caused by bismuth oxide...

Objective: Initial setting time is one of the most important properties of calcium silicate cements (CSCs) such as white mineral trioxide aggregate (WMTA). This study aimed to evaluate the effect of two methods used to reduce the particle size of WMTA, mechanical activation and chemical synthesis. Methods: WMTA without bismuth oxide (WMTA-B) was provided and divided into four groups (n=5) including: WMTA-B, WMTA-B+10 min milling, WMTA-B+30 min milling, and sol-gel...

This work represents the nature of conduction mechanism in bismuth silicate (BiSiO) nanofibers as a function of temperature and frequency. Scanning electron micrographs and X-rays diffraction patterns exhibited the formation of cubic phases of Bi4 (SiO4 )3 and Bi12 SiO20 nanofibers respectively with an average diameter of ~200 nm. Temperature dependent (300 K-400 K) electrical characterization of fibers was carried out in frequency range of ~20 Hz-2 MHz. The complex impedance analysis showed contribution from bulk and intergranular parts of nanofibers in conduction...

Bismuth oxide (monoclinic α-Bi2 O3 ) and zirconium oxide (monoclinic ZrO2 ) are the most popular radiopacifiers in commercial Portland cement-based endodontic restoratives, yet their effects on the setting and hydration reactions are not fully understood. This study compares the impact of 20 wt.% of Bi2 O3 or ZrO2 on the early hydration reactions and C-S-H gel structure of white Portland cement (WPC). Cement paste samples were hydrated at 37.5 °C prior to analysis by 29 Si and 27 Al magic angle spinning nuclear magnetic resonance spectroscopy at 3 h and 24 h, and transmission electron microscopy at 3 h...

Strontium Bismuth Borosilicate (SrBiBS as N) glasses doped with Tb3+ ions (N: Tb) and co-doped with Sm3+ /Tb3+ (N: SmTb) were synthesized through the process of classical melt quenching. The structural and optical properties are investigated through energy dispersive spectroscopy; X-ray diffraction, Differential thermal analysis (DTA) and Fourier transform infrared spectra (FTIR), Optical absorption (OA) and photoluminescence (PL) spectral studies. X-ray diffraction indicates amorphous nature of glass. DTA curves explained the thermal stability and stress parameters of glasses...

BACKGROUND: Recently, a new generation of calcium silicate-based root canal sealers has been developed. These new types of sealers have the ability to set in wet environment, have high alkalinity and present potential antimicrobial activity. OBJECTIVES: The aim of this study was to determine the chemical composition and microstructure of 2 novel calcium silicate-containing root canal sealers - TotalFill® BC Sealer and GuttaFlow® Bioseal. MATERIAL AND METHODS: The tested sealers were prepared according to the manufacturers' instructions...

The "controlled" synthesis of metastable γ-Bi2 O3 by solution based approaches was reported several times recently, but the formation of Bi12 SiO20 in the presence of trace amounts of silicates renders the results to be questionable. Here, the preparation of the Sillenite γ-Bi2 O3 and the Sillenite-type Bi12 SiO20 starting from the polynuclear bismuth oxido cluster [Bi38 O45 (O2 CC3 H5 )24 (DMSO)9 ] is reported. γ-Bi2 O3 crystallizes after calcination at 800 °C of the silicate-free hydrolysis product "[Bi38 O45 (OH)24 ]" on a silver sheet...

The effect of thermal annealing on the luminescent and laser properties of high-germania-core silicate fibers doped with bismuth was investigated. We studied the behavior of optical absorption assigned to the bismuth-related active centers associated with germanium as well as the behavior of unsaturable absorption in annealed fibers with respect to the Bi content. The dependence of the increment of the active center content on the Bi concentration in the annealed fibers was obtained. We achieved laser oscillations near a wavelength of 1700 nm with a slope efficiency of 18% using a 8...

Low levels of transition metal oxides in alkali borosilicate glass systems can drastically influence crystallisation and phase separation properties. We investigated the non-monotonic effect of manganese doping on suppressing crystallisation, and the influence on optical properties by iron oxide doping, in terms of local atomic structure. Structural models based on empirical potential structure refinement were generated from neutron and X-ray scattering data, and compared against multinuclear solid-state NMR...

AIM: To evaluate setting time, pH, solubility and surface roughness of MTA+ and ProRoot MTA and characterize their hydration under several curing conditions. METHODOLOGY: Specimens were prepared to evaluate setting time (n = 6 for each group, specimen dimensions 10 × 8 × 5 mm), solubility (n = 6 for each group, specimen dimension 20 mm in diameter and 1.5 mm thick) after 1 and 28 days, pH (n = 10 for each group, specimen dimensions 10 mm in diameter and 1 mm thick) after 1, 7, 14, 21 and 28 days and surface roughness (n = 10 for each group, specimen dimensions 4 mm in diameter and 3 mm high) after 28 days when cements were cured at 95% humidity or immersed in saline or HBSS at 37 °C...