scholarly journals Could night-guards be used as a simple method to detect leached-elements from dental restorations intra-orally? A study on amalgam restorations

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1786
Author(s):  
Rasha Mohamed Abdelraouf

Background: Detection of leached-elements from dental restorations intra-orally has been a subject of prime importance in dental research. However, this is challenging as most of the present techniques have some limitations. In this study, a new simple method was proposed via using night-guards. Thus, the aim of the study was to verify if night-guards could detect leached-elements from restorations as dental amalgam. Methods: Ten upper custom-made night-guards were fabricated for patients suffering from bruxism, who had amalgam-restorations in their upper molars. The night-guards were delivered to the patients and they were instructed to wear the night-guards during when they were asleep. After six months, the night-guards were taken from the patients to be analyzed. A new unused night-guard was fabricated from the same material to be used as a control. In the used night-guards, two areas were studied: the fitting surfaces contacting the amalgam restorations and the fitting surfaces not contacting amalgam restorations. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Analysis (EDXA) were used to examine the structural and elemental changes in the night-guards.   Results: SEM of the unused night-guard revealed a homogenous structure, and the composition was carbon and oxygen, as shown using EDXA (C=88.9wt% and O=11.1wt%). By contrast, the fitting surfaces of the night-guards contacting amalgam restorations showed numerous lustrous particles. Elemental analysis of these areas showed the presence of mercury and sulfur, in addition to carbon and oxygen (Hg=21.2wt%, S=2.5wt%, C=67.1wt% and O=9.2wt%). The night-guards’ fitting surfaces not contacting amalgam restorations showed slight cracking, and the composition was carbon and oxygen (C=88.3wt% and O=11.7 wt%).  Conclusions: Analyzing fitting surfaces of night-guards contacting dental restorations, such as amalgam, could aid in understanding the nature of leached-elements from these restorations intra-orally. However, further studies about its application upon dental-restorations other than amalgam are recommended.

2012 ◽  
Vol 535-537 ◽  
pp. 280-283 ◽  
Author(s):  
Hao Ran An ◽  
Feng Shi Cai ◽  
Xue Wei Wang ◽  
Zhi Hao Yuan

Different morphology CuO nanostructures, including platelets, flower-like were simply synthesized at 350 °C controlled by droplet on hydrophobic substrate. This is a simple method which does not require any template, catalyst, or surfactant but can control the morphology of CuO from platelets to flowerlike. The morphologies are strongly dependent on the volume of droplet. Scanning electron microscopy (SEM), Optical microscope and X-ray diffraction (XRD) were used to observe the morphology, crystallinity, and chemical composition of the CuO structures. Growth mechanisms for shape selective CuO synthesis were proposed based on these results.


1995 ◽  
Vol 7 (4) ◽  
pp. 433-441 ◽  
Author(s):  
Salah A EI-Shatoury

Coordination polymers of [2,2'-(ethandiylidenedinitrilo) diphenol) have been prepared with the metal ions Cu(II), Ni(1I) and Cr(III). They were characterized by elemental analysis, IR and electronic spectra. The metal content in all polymers was found to be consistent with a 1:1 (metal:ligand) stoichiometry. The thermal behaviour of these coordination polymers has been studied by thermogravimetric and DSC analyses in air up to 500 C. The crystallinity of the formed polymers was determined by x-ray analysis. The morphological structures of these polymers were determined by scanning electron microscopy.


2006 ◽  
Vol 17 (1) ◽  
pp. 77-89 ◽  
Author(s):  
Douglas H. Ubelaker ◽  
Karen E. Stothert

AbstractThe relationship between Andean coca use and dental deposits is explored through the use of scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS). Elemental analyses of samples of large dental deposits from archeologically recovered skeletons from Ecuador dating between 500 B.C. and A.D. 1532 are compared with those of normal calculus deposits of individuals from North America (modern and precontact), of normal tooth structure and of samples of alkali recovered from Ecuadorian artifacts thought to have been employed in coca use. Spectral analysis revealed homogeneity among all dental samples (deposits and structure) and that they are distinct from the elemental pattern revealed in the analysis of the artifact alkalis.


2014 ◽  
Vol 215 ◽  
pp. 158-162
Author(s):  
Liudmila E. Bykova ◽  
V.G. Myagkov ◽  
I.A. Tambasov ◽  
O.A. Bayukov ◽  
Victor S. Zhigalov ◽  
...  

A simple method for obtaining ZnO-Fe3O4 nanocomposites using solid-state reaction Zn + 3Fe2O3 ZnO + 2Fe3O4 is suggested. An analysis of the characteristics and properties of ZnO-Fe3O4 nanocomposites was carried out by a combination of structural and physical methods (X-ray diffraction, scanning electron microscopy, photoelectron spectroscopy, Mössbauer measurements, X-ray fluorescent analysis, and magnetic measurements). The magnetization of the hybrid ZnO-Fe3O4 films is equal to 440 emu/cm3. The resulting Fe3O4 nanoparticles are surrounded by a ZnO shell and have sizes ranging between 20 and 40 nm.


Author(s):  
David M. Chapman

When scanning electron microscopy became integrated with X-ray micro-analysis, it became an easy matter to localize an object and perform a semi-quantitative elemental analysis of atoms of atomic number 11 or higher using an energy dispersive spectrometer. This technique is used in the present study to determine the chemistry of the statoliths of eight hydromedusae, two scyphomedusae, one cubozoan and a ctenophore with respect to their comparative biomineralization and the relationship of the mineral to their taxonomy.


2012 ◽  
Vol 57 (2) ◽  
pp. 495-501 ◽  
Author(s):  
P. Żabiński ◽  
A. Franczak ◽  
R. Kowalik

Electrocatalytically Active Ni - Re Binary Alloys Electrodeposited with Superimposed Magnetic FieldThe aim of this work was to obtain Ni-Re binary alloy by a simple method of electrodeposition. Nickel - rhenium alloys have been deposited from nickel sulfamate and ammonium perrhenate electrolyte with citrate-anion additives. The effect of magnetic field superimposed during electrodeposition was studied. The impacts of that parameter on hydrogen evolution process for obtained Ni-Re alloys were examined. The deposited layers were determined by optical and scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF).


Author(s):  
Aleksandr S. Kazachenko ◽  
Olga Yu. Fetisova ◽  
Aleksandr V. Antonov ◽  
Galina N. Bondarenko ◽  
Valentine V. Sychev

Xanthan is an important polysaccharide widely used in many industrial fields. It is produced by the bacteria Xanthomonascampestris. Chemical modification of xanthan can open up new horizons for its use. In this work, xanthan butyl ester was obtained for the first time by the interaction of xanthan and bromobutane using sodium hydroxide as a catalyst. The composition and structure of the obtained new xanthan derivative was studied by elemental analysis, IR spectroscopy, X-ray phase analysis, scanning electron microscopy and thermal analysis. The introduction of a butyl group into the xanthan molecule was proved by elemental analysis and IR spectroscopy by the appearance of corresponding bands. It was shown by X-ray phase analysis that xanthan butyl ether has a more X-ray amorphous structure in comparison with the original xanthan. It was shown by scanning electron microscopy that xanthan butyl ether powder consists of particles of a larger size and a layered structure in comparison with the original xanthan. It has been shown by thermal analysis that xanthan butyl ether is less thermostable than the starting xanthan


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