Despite being able to adhesively restore teeth, adhesives and cement do not possess any anticariogenic protection potential, by which caries recurrence may still occur and reduce the clinical lifetime of adhesive restorations. Several antibacterial agents have been incorporated into dental adhesives and cement to render them anticariogenic. Due to an additional therapeutic effect, such materials are classified as 'dental combination products' with more strict market regulations.
View Article and Find Full Text PDFOctacalcium phosphate (OCP) has been considered as the layer component of calcium phosphate, but whether it achieves the ionic-exchange ability of conventional layer components is unclear. As OCP is highly biocompatible, understanding its ionic-exchange properties would potentially expand its pharmaceutical and medical applications. Herein, we demonstrate that the substituted cations in ammonium (NH)-substituted octacalcium phosphate (OCP-NH) and sodium (Na)-containing ammonium phosphate solutions undergo ion exchanges with OCP interlayers.
View Article and Find Full Text PDFThis study examined the controlled release of cetylpyridinium chloride (CPC) from a tissue conditioner (TC) containing CPC-montmorillonite (CPC-Mont), the associated antimicrobial activity, and oral mucosa irritation. The CPC release test was performed daily for 28 days in three test solutions: distilled water, 0.2 M NaCl, and 0.
View Article and Find Full Text PDFSeveral dental materials contain silver for antibacterial effect, however the effect is relatively low. The reason for the lower antibacterial efficacy of silver is considered to be the fact that silver ions bind to chloride ions in saliva. To develop new effective silver antibacterial agents that can be useful in the mouth, we synthesized two novel amino acid (methionine or histidine)-silver complexes (Met or His-Ag) loaded with montmorillonite (Mont) and analyzed their antibacterial efficacy.
View Article and Find Full Text PDFSince the introduction of biomaterials, infection has been a serious problem in clinical operations. Although several studies have introduced hybrid materials of calcium phosphate and Ag nanoparticles (NPs) that exhibit antibacterial activity, released Ag ions and Ag NPs are highly cytotoxic and the materials require complex fabrication techniques such as laser irradiation. In this study, we introduce a simple one-pot synthesis method based on crystal-engineering techniques to prepare Ag-substituted octacalcium phosphate (OCP-Ag) powder that simultaneously exhibits antibacterial activity, little change in color, and low cytotoxicity, thereby overcoming the shortcomings of calcium phosphate as a biomaterial.
View Article and Find Full Text PDFPurpose: The mechanical properties, antimicrobial activity, and biocompatibility of a novel antimicrobial tissue conditioner containing cetylpyridinium chloride with montmorillonite (CPC-Mont) were evaluated.
Methods: To examine the mechanical properties of the novel material, hardness, consistency, and penetration tests were conducted. Antimicrobial activity against Candida albicans (C.
Octacalcium phosphate (OCP) is a layered type of calcium phosphate that shows promise for pharmaceutical and biomedical applications because it offers both excellent biocompatibility and a unique, robust crystal structure that readily accepts substitution by various molecules. Although several cations can be incorporated into the OCP crystal lattice by ionic substitution, little is known about the relative probability of different ions to substitute into the OCP crystal lattice. In this study, we focus on Na and NH4, which are known to enter the OCP crystal lattice by ionic substitution.
View Article and Find Full Text PDFObjective: For bonding indirect restorations, some 'universal' adhesives incorporate a silane coupling agent to chemically bond to glass-rich ceramics so that a separate ceramic primer is claimed to be no longer needed. With this work, we investigated the effectiveness/stability of the silane coupling function of the silanecontaining experimentally prepared adhesives and Scotchbond Universal (3MESPE).
Methods And Materials: Experimental adhesives consisted of Scotchbond Universal and the silane-free Clearfil S3 ND Quick (Kuraray Noritake) mixed with Clearfil Porcelain Bond Activator (Kuraray Noritake) and the two adhesives to which γ-methacryloxypropyltrimethoxysilane (γ-MPTS) was added.
Due to the widespread use of indium tin oxide (ITO), it is important to investigate its effect on human health. In this study, we evaluated the cellular effects of ITO nanoparticles (NPs), indium chloride (InCl3) and tin chloride (SnCl3) using human lung epithelial A549 cells. Transmission electron microscopy and inductively coupled plasma mass spectrometry were employed to study cellular ITO NP uptake.
View Article and Find Full Text PDFIndium tin oxide (ITO) is widely used in liquid crystal displays (LCDs) or plasma and mobile phone displays. Elevated production and usage of ITO in such displays have led to increased concerns over the safety of industrial workers exposed to particulate aerosols produced during cutting, grinding and polishing of these materials. However, the cellular effects of ITO nanoparticles (NPs) are still unclear, although it has been reported that micro-scale ITO particles induce cytotoxicity.
View Article and Find Full Text PDFThe present work demonstrates a valuable approach to developing quartz crystal microbalance (QCM) sensor units inexpensively for reliable determination of analytes. This QCM sensor unit is constructed by inkjet printing equipment utilizing background noise removal techniques. Inkjet printing equipment was chosen as an alternative to an injection pump in conventional flow-mode systems to facilitate the commercial applicability of these practical devices.
View Article and Find Full Text PDFThe details of the ion exchange properties of layered H2TiO3, derived from the layered Li2TiO3 precursor upon treatment with HCl solution, with lithium ions in the salt lake brine (collected from Salar de Uyuni, Bolivia) are reported. The lithium adsorption rate is slow, requiring 1 d to attain equilibrium at room temperature. The adsorption of lithium ions by H2TiO3 follows the Langmuir model with an adsorptive capacity of 32.
View Article and Find Full Text PDFJ Colloid Interface Sci
February 2011
This study presents a rare use of layered double hydroxides of Fe(II) and Al(III) (Fe-Al LDH), as reported for the first time for bromate removal from aqueous solutions. The Fe-Al LDH samples were prepared with Fe/Al molar ratios of 1-4 using a co-precipitation method at pH 7, with subsequent hydrothermal treatment at 120°C. The Fe-Al LDH (molar ratio of Fe/Al=1, 2) with a layered structure exhibited nearly complete removal of bromate from initial concentration of 100μmol/dm(3) at a wide pH range of 4.
View Article and Find Full Text PDFA novel layered double hydroxide of Mg and Al with composition [Mg(0.96)Al(4.00)(OH)(12)]Cl(1.
View Article and Find Full Text PDFJ Colloid Interface Sci
September 2010
We prepared a novel Zr-modified MgFe-LDH(CO(3)) composite by adding a mixed solution of MgCl(2), FeCl(3), and ZrOCl(2) and another mixed solution of 1mol/dm(3) NaOH and 1mol/dm(3) Na(2)CO(3) to distilled water at a constant pH of 10. The composite exhibited only a poorly crystalline structure, resembling that of layered double hydroxides (LDH) from X-ray diffraction. The phosphate uptake is dependent on pH, decreasing with an increase in pH.
View Article and Find Full Text PDFNanocarbons, such as carbon nanohorns (CNH) and carbon nanotubes, are materials of interest in many fields of science and technology because of their remarkable physical properties. We report here a novel approach for using NIR laser-driven CNH as an antiviral agent. NIR laser-driven functional CNH complexes could open the way to a new range of antiviral materials.
View Article and Find Full Text PDFPhotoluminescence (PL) intermittency characteristics are examined for single quantum dots (QDs) in a CdSe QD sample synthesized at a slow rate at 75 degrees C. Although the PL quantum efficiency was relatively low ( approximately 0.25), we noticed that the PL intensity of single CdSe QDs fluctuated on a subsecond time scale with short-lived "on" and "off" states.
View Article and Find Full Text PDFThe formation of narrow size dispersed and nanometer size aggregates (clusters) of cadmium selenide (CdSe) quantum dots (QDs) and their temperature-sensitive photoluminescence (PL) spectral properties close to room temperature (298 K) are discussed. CdSe QDs formed stable clusters with an average diameter of approximately 27 nm in the absence of coordinating solvents. Using transmission electron microscopy (TEM) imaging, we identified the association of individual QDs with 2-5 nm diameters into clusters of uniform size.
View Article and Find Full Text PDFThe formation of todorokite-type manganese oxide (TodMO) by hydrothermal soft chemical reaction (Mg2+ exchange followed by hydrothermal treatment) was studied using three kinds of Na-type birnessite (Na-BirMO) with different crystallinities. Buserite (BusMO) formation by Mg2+ exchange and TodMO formation by hydrothermal treatment progressed in a similar manner regardless of the crystallinity of the initial Na-BirMO, but the crystallinity of the synthesized TodMO depended on that of the initial Na-BirMO. Particle morphology of the synthesized TodMO was related to the crystallinity of the initial Na-BirMO.
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