Increase In Fluoride Ion Concentration Research Articles

Gelation–based visual detection of fluoride ion: Strategic use of silyl protection–deprotection chemistry

• A gelation-based visual detection of fluoride ion is reported. • Fluoride ion converted a triphenylsilyl group-containing gelator (gel) into a nongelator (gel degradation). • Quantitative and semi-quantitative detection methods are reported. • Fluoride ion detection limit is considerably better than many existing gelation-based methods. We describe the design, synthesis, and visual fluoride ion detection by a new small-molecule gelator in this work. This gelator contains a triphenylsilyl group which is easily removed in the presence of fluoride ion. The strategic use of silyl group protection-deprotection chemistry enabled the detection of fluoride ion visually. We investigated two different routes for this purpose. In the first route, gels were responsive to fluoride ion and degraded in its presence. Gels degraded faster with an increase in fluoride ion concentration. Fluoride ion quantification was possible by correlating fluoride ion concentrations with gel-degradation times. In the second route, when gelation tests were performed in the presence of fluoride ion, gel formation was suppressed, and multiple visually distinguishable states were obtained. A semi-quantitative analysis for fluoride ion was achieved in this case. The performance and detection limit of this new gelator is superior to many existing gelation-based methods. Furthermore, the gels were fully characterized using SEM, TEM, FTIR, XRD, contact angle, fluorescence, and UV–vis spectroscopy techniques.

EFFECTIVENESS OF SILVER DIAMINE FLUORIDE AND PROPOLIS FLUORIDE VARNISH APPLICATION ON DENTIN WITHIN 60 DAYS

Objective: This study sought to analyze the effectiveness of silver diamine fluoride (SDF) and propolis fluoride (PPF) varnish application on dentinwithin 60 days.Methods: We divided 60 blocks (4 mm × 4 mm × 2 mm) of human permanent teeth dentin specimens into six time-based groups: 0 days, 1 day, 7 days,14 days, 30 days, and 60 days. We then applied 20 μL SDF and PPF varnish to the specimens’ occlusal surfaces. For the fluoride test, all specimenswere submerged in deionized water, while for the flavonoid test, specimens were submerged in a solution of 20% ethanol. In the treatment group,specimens were shaken for 30 min at 45 rpm (every day) for 0–60 days, depending on group assignment. An ion selective electrode was used tomeasure fluoride ions and a spectrophotometer with 425 nm wavelength absorbance measured flavonoid absorbance. Dentin microhardness wasmeasured for 30 and 60 days sample using the Vickers microhardness tester.Results: There was an increase in fluoride ion concentration after SDF and PPF application to the dentin samples, while SDF released more fluorideions than PPF. Increased flavonoid absorbance was observed after PPF application. Dentine microhardness increased after SDF and PPF application.Conclusion: SDF and PPF application on dentin is effective within 60 days.

Monitoring the effects of a lepidopteran insecticide, Flubendiamide, on the biology of a non-target dipteran insect, Drosophila melanogaster.

Various organisms are adversely affected when subjected to chronic fluoride exposure. This highly electronegative ion present in several insecticide formulations is found to be lethal to target pests. In the present study, Drosophila melanogaster is treated with sub-lethal concentrations of a diamide insecticide formulation, Flubendiamide. Chronic exposure to the diamide (0.5-100μg/mL) was found to be responsible for increase in fluoride ion concentration in larval as well as adult body fluid. Interestingly, 100μg/mL Flubendiamide exposure resulted in 107 and 298% increase in fluoride ion concentration whereas only 23 and 52% of Flubendiamide concentration increase in larval and adult body fluid, respectively. Further, in this study, selected life cycle parameters like larval duration, pupal duration and emergence time showed minimal changes, whereas percentage of emergence and fecundity revealed significant treatment-associated variation. It can be noted that nearly 79% reduction in fecundity was observed with 100μg/mL Flubendiamide exposure. The variations in these parameters indicate probable involvement of fluoride ion in detectable alterations in the biology of the non-target model insect, D. melanogaster. Furthermore, the outcomes of life cycle study suggest change in resource allocation pattern in the treated flies. The altered resource allocation might have been sufficient to resist changes in selective life cycle parameters, but it could not defend the changes in fecundity. The significant alterations indicate a definite trade-off pattern, where the treated individuals happen to compromise. Thus, survival is apparently taking an upper hand in comparison to reproductive ability in response to Flubendiamide exposure. Graphical abstract The figure demonstrates increase in Fluoride and Flubendiamide concentrations in Drosophila melanogaster after chronic sub-lethal exposure to Flubendiamide. Treatment-induced alterations in larval and pupal duration, reduction in fecundity and alteration in male-female ratio is also observed.

Corrosion behaviour of Ti–15Mo alloy for dental implant applications

The corrosion behaviour of Ti–15Mo alloy in 0.15 M NaCl solution containing varying concentrations of fluoride ions (190, 570, 1140 and 9500 ppm) is evaluated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and chronoamperometric/current–time transient (CTT) studies to ascertain its suitability for dental implant applications. The study reveals that there is a strong dependence of the corrosion resistance of Ti–15Mo alloy on the concentration of fluoride ions in the electrolyte medium. Increase in fluoride ion concentration from 0 to 9500 ppm shifts the corrosion potential ( E corr) from −275 to −457 mV vs. SCE, increases the corrosion current density ( i corr) from 0.31 to 2.30 μA/cm 2, the passive current density ( i pass) from 0.07 to 7.32 mA/cm 2 and the double-layer capacitance ( C dl) from 9.63 × 10 −5 to 1.79 × 10 −4 F and reduces the charge transfer resistance ( R ct) from 6.58 × 10 4 to 6.64 × 10 3 Ω cm 2. In spite of the active dissolution, the Ti–15Mo alloy exhibit passivity at anodic potentials at all concentrations of the fluoride ions studied. In dental implants since the exposure of the alloy will be limited only to its ‘neck’, the amount of Mo ions released from Ti–15Mo alloy is not likely to have an adverse and hence, in terms of biocompatibility this alloy seems to be acceptable for dental implant applications. The results of the study suggest that Ti–15Mo alloy can be a suitable alternative for dental implant applications.

Biomimetic fabrication of fibrin/apatite composite material

Bidirectional diffusion of the Ca and PO4 solutions into the fibrin gel was performed at various pH conditions and fluoride concentrations to generate organic/inorganic composite materials mimicking biomineralization. The minerals produced in this system had a higher crystallinity than those generated by the solution mineralization system. The minerals generated in fibrin gel varied depending on the pH conditions as follows: Dicalcium phosphate dihydrate (DCPD) in the noncontrolled pH solution, the DCPD and octacalcium phosphate (OCP) mixture at pH 7.4, and the OCP and hydroxyapatite (HAp) mixture at pH 9.0. When fluoride ions were added in the range of 2-500 ppm, the minerals produced at pH 7.4 altered from OCP/HAp to HAp/fluorapatite (FAp). In addition, the crystallinity of the obtained minerals increased with an increase in fluoride ion concentration, and the solubility was inversely correlated to crystallinity. In conclusion, we established a novel fabrication method for synthesizing organic/inorganic composite materials composed of fibrin and calcium phosphate and revealed that the characteristics of the minerals in the synthesized material can be controlled by the fabrication condition.

Study of factors affecting uranium stripping from DEHMA/TOPO solvent by factorial design

Uranium is recovered from wet phosphoric acid by a DEHPA/TOPO mixture. It was found that stripping is the most crucial step in this process. Several studies were undertaken to understand this process in greater depth. This study investigates the main operating variables, mainly concentration of phosphoric acid, temperature and concentration of iron on stripping, by the method of factorial design. A mathematical model was developed to represent the data. Another experiment was undertaken to find out the effect of fluoride ion on stripping. The results agree well with those of earlier investigations, namely that it is beneficial to increase the concentration of phosphoric acid and the temperature. The increase in fluoride ion concentration leads to an enhancement of the stripping distribution ratio.