Detection of Ni, Fe, and Cr Released in Saliva after Prefabricated Metal Crown Placement in Children

Dental caries is a public health problem worldwide according to WHO data. Among treatments in pediatric dentistry, prefabricated metal crowns (PMCs) have been one of the most successful options since they were introduced in cases of considerable tooth destruction. Our objective was to detect the presence and concentration of iron (Fe), chromium (Cr), and nickel (Ni) in saliva of patients who require rehabilitation with PMCs, before and after their placement. A quasi-experimental study was performed in 32 patients who attended dental care in a pediatric dentistry clinic at a public university and who required rehabilitation with PMCs. Parametric tests (ANOVA and Pearson correlation) were performed, and a p ≤ 0.05 was considered statistically significant. Statistically significant differences were found when comparing the Ni release before, 1 week, and 1 month after placing the crowns. Similarly, we observed a positive correlation between the number of crowns and Ni release. No tests were performed for Fe and Cr because the amounts of these metals were less than 0.1 ppb, which was not detectable by inductively coupled plasma optical emission spectrometry (ICP-OES). The levels of Fe, Cr, and Ni released were below toxic health levels. Studies are required to evaluate whether this release has negative effects at cellular levels.

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Effect of wood biomass components on self-heating

Bioresources and Bioprocessing ◽

10.1186/s40643-021-00373-7 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Nozomi Miyawaki ◽

Takashi Fukushima ◽

Takafumi Mizuno ◽

Miyao Inoue ◽

Kenji Takisawa

Keyword(s):

Moisture Content ◽

Inductively Coupled Plasma ◽

Optical Emission ◽

Chemical Oxidation ◽

Spontaneous Ignition ◽

Emission Spectrometry ◽

Inductively Coupled ◽

Self Heating ◽

Inorganic Substances ◽

Before And After

AbstractBiomass may ignite due to biological oxidation and chemical oxidation. If this phenomenon (spontaneous ignition) is controlled, it would be possible to produce biochar at a lower cost without the need for an external heat resource. We investigated if self-heating could be controlled by using sawdust and bark chips. When sawdust and bark chips were used under controlled conditions, the bark chips temperature increased to the torrefaction temperature. The ash content of bark chips was ~ 2%d.b. higher than that of sawdust; consequently, the inorganic substances contained in the bark chips might affect the self-heating. Self-heating was suppressed when inorganic substances were removed by washing with water. Therefore, the inorganic substances in the biomass might have affected self-heating. The inorganic element contents of the bark chips were measured by inductively coupled plasma optical emission spectrometry before and after washing. The potassium content of the bark chips was reduced remarkably by washing, and there was a possible influence of potassium on self-heating. Finally, the effect of moisture content on self-heating was investigated to obtain stable reactivity. Thus, at a moisture content of 40%w.b., a steady self-heating behavior may be realized.

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Reactivity of Metakaolin in Alkaline Environment: Correlation of Results from Dissolution Experiments with XRD Quantifications

Materials ◽

10.3390/ma13102214 ◽

2020 ◽

Vol 13 (10) ◽

pp. 2214

Author(s):

Sebastian Scherb ◽

Mathias Köberl ◽

Nancy Beuntner ◽

Karl-Christian Thienel ◽

Jürgen Neubauer

Keyword(s):

Inductively Coupled Plasma ◽

Optical Emission ◽

Systematic Investigation ◽

Attenuated Total Reflection ◽

Emission Spectrometry ◽

Alkaline Solutions ◽

X Ray ◽

Inductively Coupled ◽

Before And After ◽

Congruent Dissolution

Systematic investigation of filtrates and filter residues resulting from a 24 h treatment of metakaolin in different alkaline solutions were performed. On filtered metakaolin particles, inductively coupled plasma-optical emission spectrometry (ICP-OES) measurements reveal an enrichment of iron and titanium, which suggests an inhomogeneous distribution of these cations. Since the SiO2/Al2O3 ratio remains constant in all filter residues examined, the dissolution of the Si and Al monomers is congruent. Structural differences, identified by attenuated total reflection–Fourier transform infrared spectroscopy (ATR-FTIR) as a consequence of alkali uptake, influence the X-ray scattering contribution of metakaolin, and thus quantifications with the partial or no known crystal structure (PONKCS) method. This leads to deviations between the degree of reaction calculated from Si and Al solubility from filtrate and that quantified by quantitative powder X-ray diffraction (QPXRD) using the filter residue. Nevertheless, the described changes do not cause a shift in the X-ray amorphous hump in case of congruent dissolution, and thus allow the quantification of the metakaolin before and after dissolution with the same hkl-phase model.

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Determination of Heavy Metals in Groundwater Around Al-Buraihi Sewage Station in Taiz City, Yemen

Journal of Health and Pollution ◽

10.5696/2156-9614-11.30.210604 ◽

2021 ◽

Vol 11 (30) ◽

Author(s):

Raya Qaid Alansi ◽

Abdelhafeez M.A. Mohammed ◽

Mahmoud M. Ali ◽

Wadie Ahmed Mokbel Ghalib ◽

Sajan Chimmikuttanda Ponnappa

Keyword(s):

Heavy Metals ◽

Inductively Coupled Plasma ◽

Heavy Metal Contamination ◽

Pearson Correlation ◽

Optical Emission ◽

International Standards ◽

Emission Spectrometry ◽

Inductively Coupled ◽

Financial Interests ◽

Wastewater Samples

Background. In recent years, mitigation of groundwater contamination resulting from the limited availability of freshwater for domestic use has become an important issue. The presence of heavy metals in water could have adverse effects on both plant and animal life. Objectives. The main objective of the present study was to determine possible heavy metal contamination in groundwater around Al-Buraihi sewage station in Taiz, Yemen and to understand possible sources of contamination and their relationships with groundwater. Methods. Wastewater samples were collected from a wastewater stabilization pond from Al-Buraihi sewage station and borewell water samples were collected from the vicinity. The presence of heavy metals was quantified using inductively coupled plasma-optical emission spectrometry (ICP-OES). Pearson correlation test was performed to understand the relationship between wastewater and groundwater samples. Results. Physical variables including pH, electrical conductivity (EC), dissolved oxygen (DO) and temperature and elements such as silver (Ag), arsenic (As), aluminum (Al), barium (Ba), boron (B), cadmium (Cd), chromium (Cr), iron (Fe), molybdenum, nickel (Ni), selenium (Se) and zinc (Zn) exceeded the permissible limits recommended by international standards in wastewater samples. Conclusions. Treated sewage wastewater in the study area is not suitable for irrigation as the elements/heavy metals are accumulated in soil and plants and may be accumulated in humans and animals through bio-accumulation. In addition, these heavy metals reach the water table and aquifers through percolation, thereby polluting groundwater. Competing Interests. The authors declare no competing financial interests.

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Ultramarine colored: Solid-phase elution of Pt into perovskite oxides

Journal of Materials Research ◽

10.1557/jmr.2007.0340 ◽

2007 ◽

Vol 22 (10) ◽

pp. 2647-2650 ◽

Cited By ~ 4

Author(s):

Katsuhiro Nomura ◽

Masakazu Daté ◽

Hiroyuki Kageyama ◽

Susumu Tsubota

Keyword(s):

Inductively Coupled Plasma ◽

Preparation Method ◽

Solid Phase ◽

Optical Emission ◽

Perovskite Oxides ◽

Emission Spectrometry ◽

Chemical Compositions ◽

Inductively Coupled ◽

Before And After ◽

Perovskite Lattice

We have found a new route for preparing Pt containing perovskites. Ba containing perovskite powder, (La0.7Sr0.2Ba0.1)ScO3–δ (LSBS), reacted with Pt foil at 1898 K in air, and formed ultramarine colored Pt containing perovskite, (La0.7Sr0.2Ba0.1)(Sc,Pt)O3–δ, without changing the GdFeO3-type structure. The chemical compositions of the samples before and after firing, measured with inductively coupled plasma (ICP) optical emission spectrometry, were La: Sr: Ba: Sc = 0.70(1): 0.206(4): 0.101(2): 0.98(2) and La: Sr: Ba: Sc: Pt = 0.70(1): 0.197(4): 0.085(2): 0.95(2): 0.0062(2), respectively. The reaction proceeded not only at the interface between perovskite powder and Pt foil, but also over whole powder surface. We name this new preparation method the “solid-phase elution (SE) method”, because the process involves elution of Pt ions from the Pt foil to the LSBS perovskite lattice. It is expected that we can control the amount of Pt introduced into perovskites by using the SE method after optimizing the reaction time and temperature.

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