Search results for "fluoride"
showing 10 items of 314 documents
ESCA-Analysis of tin compounds on the surface of hydroxyapatite
1997
The formation of tin compounds on the surface of hydroxyapatite, the main crystalline component of teeth, is discussed controversially. SnF2 is used as an anticaries agent in toothpaste preparations. Pure hydroxyapatite (HAP) is treated with extracts of commercially available toothpastes containing tin fluoride and analyzed by electron spectroscopy (ESCA). Survey spectra and depth profiles are recorded. The chemical shifts measured for the HAP samples are compared with those of standard tin compounds. It is concluded that on the surface of hydroxyapatite a mixture of two-valent fluoro-phosphato compounds is formed. SnO is not found in the mixture.
Effects of treatment with three types of varnish remineralizing agents on the microhardness of demineralized enamel surface
2019
Background Remineralization of incipient caries is one of the goals in dental health care ,especially in pediatric dentistry. The present study aimed at comparing the effects of MI varnish (3M (United states)) , Nano paste( FGM(Brezil) ), 5% sodium fluoride varnish) DuraphatColgate (united states) ) on remineralization of enamel lesions. Material and Methods In this in-vitrostudy, 60 intact human pre-molars, were randomly allocated to four groups of 15. Baseline surface microhardness in three points in the center of the polished area was measured. After two days of immersion in demineralizing solution, microhardness of all samples was measured. Afterward, groups 1-3 under-went treatment wit…
Hybrid Tribo-Piezo-Electric Nanogenerator with Unprecedented Performance Based on Ferroelectric Composite Contacting Layers
2019
This research was supported by the European Regional Development Fund within the project ‘‘Hybrid energy harvesting systems’’ 1.1.1.1./16/A/013.
Fluoruro en aguas minerales naturales envasadas en España y prevención de la caries dental
2015
ResumenObjetivoEl propósito del estudio es conocer la concentración en flúor de las aguas minerales naturales comercializadas en España para poder prevenir la caries dental sin el riesgo de causar fluorosis dental.DiseñoEstudio descriptivo y transversal a lo largo de 2012.EmplazamientoAguas minerales naturales comercializadas en España.ParticipantesTres muestras con fechas distintas de embotellado de 109 marcas de aguas minerales naturales (97 marcas españolas y 12 aguas importadas).Medición principalDeterminación analítica por cromatografía iónica del contenido en fluoruro en el agua.ResultadosLa concentración mediana de fluoruro de las aguas minerales naturales españolas es de 0,22 (rango…
Automated synthesis and purification of [18F]fluoro-[di-deutero]methyl tosylate
2013
Automated synthetic procedures of [ 18 F]fluoro-[di-deutero]methyl tosylate on a GE TRACERlab FX F-N module and a non-commercial synthesis module have been developed. The syntheses included azeotropic drying of the [ 18 F]fluoride, nucleophilic 18 F-fluorination of bis(tosyloxy)-[di-deutero]methane, HPLC purification and subsequent formulation of the synthesized [ 18 F]fluoro-[di-deutero]methyl tosylate (d2-[ 18 F]FMT) in organic solvents. Automation shortened the total synthesis time to 50min, resulting in an average radiochemical yield of about 50% and high radiochemical purity (>98%). The possible application of this procedure to commercially available synthesis modules might be of signi…
Structural insights into the GTPase domain of Escherichia coli MnmE protein
2007
The Escherichia coli MnmE protein is a 50-kDa multidomain GTPase involved in tRNA modification. Its homologues in eukaryotes are crucial for mitochondrial respiration and, thus, it is thought that the human protein might be involved in mitochondrial diseases. Unlike Ras, MnmE shows a high intrinsic GTPase activity and requires effective GTP hydrolysis, and not simply GTP binding, to be functionally active. The isolated MnmE G-domain (165 residues) conserves the GTPase activity of the entire protein, suggesting that it contains the catalytic residues for GTP hydrolysis. To explore the GTP hydrolysis mechanism of MnmE, we analyzed the effect of low pH on binding and hydrolysis of GTP, as well…
Effect of silver diamine fluoride on the bond durability of normal and carious dentin
2019
Background Silver diamine fluoride (SDF) has attracted attention because of its clinical success in arresting dentin caries. It has been shown that it can inhibit matrix metalloproteinases and cysteine cathepsins. These two properties might be beneficial in bonding to caries-affected dentin (CAD). Therefore, the present study aimed to investigate the effect of SDF on the durability and bond strength to the CAD. Material and Methods Forty-eight third molars with occlusal caries were used. The roots were cut, and the occlusal enamel was removed. The CAD area surrounded by the normal dentin (ND) was exposed. All the specimens were bonded with an etch-and-rinse adhesive, but half of them were t…
An in vitro evaluation of the efficacy of a novel iontophoresis fluoride tray on remineralization
2013
Objectives: The aim of this study is to determine the effects on remineralization of a novel iontophoresis device called "Fluorinex", conventional (acidulated phosphat fluoride) APF gel treatment, and conventional ionthophoresis device comparatively by laser fluorescence measurements. Study Design: Artificial incipient carious lesions were created on immature, 60 intact premolar and molar teeth with no defects. The specimens were randomly allocated to four groups. In the first group 1.23% APF gel was applied to specimens by conventional method for 4 minutes and in the second group 2% (sodium fluoride) NaF solution applied by conventional iontophoresis device for 4 minutes. In Fluorinex grou…
Comparative cariostatic efficacy of a novel Nano-silver fluoride varnish with 38% silver diamine fluoride varnish a double-blind randomized clinical …
2019
Background To evaluate the clinical cariostatic efficacy of a concocted 5% Nano-silver incorporated Sodium fluoride (NSSF) dental varnish with 38% Silver diamine fluoride (SDF) in preventing the progression of dentinal caries of primary molars. Material and methods A total of 159 active dentinal carious lesions in primary molars (from 50 children) were selected and randomly divided into two groups; NSSF and SDF. Varnish application was performed at the baseline visit and follow-up is carried out at 1, 3, 6 and 12 months. Parameters such as caries activity, depth, size, colour, and presence or absence of pain were noted at baseline and follow-up visits. Results The intergroup comparison of c…
Enhanced interfacial lithium storage in nanocomposites of transition metals with LiF and Li2O: Comparison of DFT calculations and experimental studies
2008
Abstract Me/LiX nanocomposites (Me – transition metal and X = F or O) exhibit extra lithium storage, with pseudo-capacitive behavior and high-rate performance. While LiX surface layers or the interfacial core serves as hosts for extra Li, atoms of contacting transition metal serve as electron sinks, depending on Me electronegativity. To verify the mechanism, we have performed comparative DFT-LCAO calculations on the polar Ti|Li|Li2O(111) and non-polar Cu|Li|LiF(001) interfaces with extra Li atoms inserted inside both 2D interfaces, gradually changing their concentration. Theoretical calculations confirm validity of this interfacial model for explanation of the extra storage capacity at low …