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This work presents the first report of the application of microwave-induced combustion in disposable vessels (MIC-DV) as a simple and fast sample preparation step for fluoride determination by ion-selective electrode (ISE) in leguminous seeds and oilseeds samples. Several experimental conditions of MIC-DV were evaluated, such as sample mass, absorbing solution, volume of combustion igniter, purging time with oxygen, and the use of successive combustion cycles. The accuracy of MIC-DV/ISE method was evaluated by comparing the results obtained by microwave-induced combustion and determination by ion chromatography, with agreements ranged from 94 to 106%. The method allowed to achieve relatively low limits of quantification (8.3 to 16 µg g-1) comparing to AOAC method (40 µg g-1), besides the use of small amounts of reagents, less handling of digests, making the method greener and with portable features comparing to other methods.

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Abstract Objective: To compare the fluoride release from Conventional Glass Ionomer Cement (GIC), Resin Modified GIC (RMGIC), and Cention N Alkasite Material. Material and Methods: Forty- five disc-shaped specimens of three different restorative materials (Conventional GIC, RMGIC, and Alkasite material) were made and divided into 3 groups (n=15). Fluoride release was evaluated at the end of Day 1, 7, 14, and Day 28 using fluoride ion-selective electrode. Intergroup and Intra-group analysis was done using One-way ANOVA with a Post-hoc test. A p-value of <0.05 was considered statistically significant. Results: Cention showed more fluoride release (in parts per million) than GIC and RMGIC at increased time duration. However, at the end of day 1, there was lesser fluoride release with Cention, as compared with the other groups. Conclusion: The new Alkasite restorative material showed promising results in terms of fluoride release and is better than GIC and RMGIC at increased time duration.

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Aim: To determine total fluoride (TF) concentration in Na2FPO3/Ca-based toothpastes, using fluoride ion selective electrode (F-ISE) by the direct technique, it is necessary to use acid (Ac+) to hydrolyze the FPO32- ion and to dissolve insoluble fluoride salts bound to the abrasive. For NaF/silica-based toothpastes, the use of acid is not necessary (Ac-) and a simplified protocol could be followed. Methods: Thus, we evaluated TF concentration in seven brands of NaF/silica-based toothpastes, following the validated conventional Cury's protocol (Ac+) or a simplification of this protocol (Ac-).Fluoride was analyzed with ISE calibrated with fluoride standard solutions prepared in the same conditions as the samples (Ac+ or Ac-). Results: The mean (±SD; n=21) of TF concentrations (µg F/g) found by Ac+ (971.3±191.2) and Ac- (982.4±201.3) protocols were not statistically different (t test, p=0.22). The TF concentrations found agree with those declared by the manufacturers, except for one toothpaste imported from China. Conclusion: The findings suggest that the determination of fluoride in NaF/silica-based toothpastes can be accurately made using a simplified protocol of analysis

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Introducción: Actualmente, existe una gran variedad de pastas dentales que se pueden encontrar en el mercado nacional, para diferentes propósitos. Entre éstas se hallan las empleadas para la prevención de caries. Éstas contienen fluoruro en diversas concentraciones como agente terapéutico, y casi en su totalidad estipulan en sus marbetes un contenido de 1,000 a 1,450 partes por millón (ppm) de fluoruro. Algunos estudios han mostrado que las concentraciones de fluoruro especificadas en la etiqueta y lo encontrado en el dentífrico no coinciden. Objetivo: Evaluar la concentración de fluoruro total con base en la Norma Mexicana NMX-K-539-CNCP-2013, que establece que los dentífricos no deben contener más de 1,500 ppm de fluoruro. Así como determinar si lo declarado en el marbete de sus empaques corresponde al contenido real de fluoruro. Material y métodos: El estudio se realizó, por triplicado, en 37 pastas dentífricas. El método para determinar la concentración de fluoruro fue el de ion selectivo, descrito por la Farmacopea de los Estados Unidos Mexicanos. Resultados: El promedio de concentración de este elemento fue de 1,262 ppm F- (± 170.7). El 59% de los dentífricos analizados no contienen la cantidad estipulada en el marbete. Conclusiones: Las concentraciones de fluoruro de los dentífricos se encuentran dentro de la Norma. Las concentraciones no corresponden a lo estipulado en el empaque (AU)

Introduction: Currently, there is a wide variety of toothpastes, which can be found in the national market, for different purposes. Among these are those used for the prevention of dental caries. These, contain fluoride in various concentrations as a therapeutic agent, and almost in their entirety, stipulate in their labels a content of 1,000 to 1,450 ppm of fluoride. Some studies have shown that the fluoride concentrations specified on the label, and what is found in the toothpaste do not match. Objective: To evaluate the concentration of total fluoride based on the Mexican Standard NMX-K-539-CNCP-2013, which establishes that toothpastes should not contain more than 1,500 ppm of fluoride. As well as determining if what is stated on the label of their packaging corresponds to the actual content of fluoride. Material and methods: The study was carried out, in triplicate, on 37 toothpastes. The method for determining the fluoride concentration was that of selective ion, described by the Pharmacopoeia of the United Mexican States. Results: The average concentration of this element was 1,262 ppm F- (± 170.7). Fifty nine percent of the dentifrices analyzed do not contain the amount stipulated in the label. Conclusions: The fluoride concentrations of dentifrices are within the Standard. The concentrations do not correspond to what is stipulated in the package (AU)

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OBJECTIVE: The aim of this study was to determine whether there is a correlation between acid erosion and fluoride release of conventional glass ionomer cements. METHODS: Ten specimens for each material were prepared for fluoride release tests and five for acid erosion tests separately. After placed in pH cycling solution, concentration of fluoride was measured by a fluoride-ion selective electrode each day for 15 days. For the acid erosion test, specimens were immersed in a lactic acid solution and their depth measured with a spring-loaded dial gauge. The data were submitted to 3-way ANOVA, followed by Tukey's test (p<0.05) RESULTS: All materials showed ability to elute fluoride in the 15 day period of the test, with the same pattern of high fluoride release at the first 24h. Despite this, the amount of fluoride released was statistically different among the 18 groups, with the highest for Maxxion R and the lowest for Chemfil Rock (p>0.05). The highest acid erosion values were registered for Magic Glass, Ion Z, VitroFil and Maxxion R, which exceeded the maximum stipulated by the relevant ISO test (ISO 9917-1). A positive linear correlation (r2=0.4886) was found for both properties, i.e., higher fluoride release is related to higher acid erosion. SIGNIFICANCE: Acid erosion and fluoride release are related properties of GICs, though factors such as pH and P/L ratio lead to differences between actual values for individual brands of these materials.

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Objetivo: avaliar o nível de flúor presente nas águas minerais carbogasosas e não carbogasosas envasadas no estado do Rio Grande do Sul, comparando os dados com as informações descritas nos rótulos das embalagens. Materiais e método: foram analisadas cinco marcas comerciais de água mineral. Os valores de padrão/ amostra e tampão Tisab foram utilizados em uma relação de 1:1, e as amostras foram lidas em duplicata. As amostras carbogasosas foram agitadas com bastão magnético para eliminação do gás carbônico. Para determinação de flúor, foram utilizados analisador específico de íons, eletrodo seletivo para íon flúor, eletrodo de referência Ag/AgCl de junção simples. Resultados: foram encontradas concentrações de flúor variando entre 0,13 mg F-/L e 1,31 mg F-/L, com diferenças entre os valores estipulados nos rótulos das marcas de água mineral avaliadas e as análises laboratoriais na presente investigação. Os valores de duas marcas de água mineral com flúor analisadas no estudo mostraram-se acima, considerando os valores de referência (0,6-0,8 mg F-/L), e uma marca não apresentou valores de ação preventiva contra a cárie dentária (valores abaixo de 0,6 mg F-/ L). Conclusão: conclui-se que há divergência entre os valores de íons flúor encontrados nas medições e os informados nos rótulos, sendo necessário um sistema de melhor vigilância para o controle dos níveis de flúor nas águas minerais disponibilizadas à população do estado do Rio Grande do Sul, considerando os benefícios do consumo de águas minerais para prevenção dos níveis de cárie na população. (AU)

Objective: quantify the fluoride level in carbogaseous and non-carbogaseous mineral waters bottled in the state of Rio Grande do Sul, Brazil, as well as to compare the data with the information described on the package labels. Materials and method: five brands of mineral water were analyzed. Standard/sample values and Tisab buffer were used in a ratio of 1:1, and the samples were read in duplicates. The carbogaseous samples were shaken with a magnetic rod to eliminate the carbon dioxide. For fluoride determination, a specific ion analyzer was used, as well as a fluoride ion-selective electrode, single-junction Ag/AgCl reference electrode. Results: fluoride concentrations ranging from 0.13 mg F-/L to 1.31 mg F-/L were found, with differences between the values specified in the labels of the mineral water brands evaluated and the laboratory analyses of the present investigation. The values of two brands of mineral water with fluoride analyzed in the study were high, considering the reference values (0.6-0.8 mg F-/L), and one brand did not present values of preventive action against dental caries (below 0.6 mg F-/L). Conclusion: there is a divergence between the values of fluoride ions measured and those reported on the labels, which requires a better surveillance system for controlling fluoride levels in the mineral waters offered to the population of the state of Rio Grande do Sul, Brazil, considering the benefits of mineral water consumption to prevent caries levels in the population. (AU)

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AIM: The aim of this study is to determine the influence of children's menu diversity on the absorption and excretion of fluoride. MATERIALS AND METHODS: The experimental, longitudinal, quantitative study was carried out in a city without fluoridation in water supply. A total of 16 adult volunteers (>63.9 kg) participated in the study who, after a 12-hour fast, ingested two types of children's meals, whose quantity and diversity were determined after weighing the meals best consumed by children at a kindergarten in Campinas, Sao Paulo: Simple child meal (SCM; n = 8) and hearty child meal (HCM; n = 8). The fluoride gel residual after professional application (12,300 ppm, 30.75 mg F, pH = 4.65) was simulated 15 minutes after feeding. Saliva samples (in time intervals of 0, 15, 30, and 45 minutes and 1, 2, 3, 4, 6, and 12 hours after ingestion of the fluorine solution) and urine of the volunteers were analyzed at 24 hours. Fluoride concentrations were determined using a selective ion electrode. Data were analyzed by analysis of variance for repeated measurements (PROC MIXED)/Tukey-Kramer. RESULTS: The concentrations of fluoride in saliva at 0 and 15 minutes and after 6 hours were the same between groups (p > 0.05). From 30 minutes to 4 hours after ingestion, the SCM group showed a higher concentration of fluoride in the saliva, which has a higher absorption (p < 0.05). The fluoride concentration in the urine did not differ between groups at both collection times (p > 0.05), and for both, the fluoride concentration in the urine increased in the final measurement (p < 0.05). CONCLUSION: The children's menu diversity influenced the absorption of fluoride so that the topical application of fluoride should be performed in infants fed preferably after the fuller diet and following the established guidelines to ensure the safety of the procedure. CLINICAL SIGNIFICANCE: Knowledge of the influence of the children's menu diversity on fluoride metabolism after professional application is important so that the actions of fluoride therapy may be planned in a safer manner and be based on the reality of the universe of children.

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INTRODUCTION: The development of electrochemical sensors for the detection of small molecules has already had a significant effect on the study of biology because of their selectivity and ability to measure low concentrations of small molecules that regulate various functions in living organisms. Hydrogen sulfide (H2S) is a gasotransmitter produced at low levels in several tissues including the stomach. Here, we propose a new method for detecting low concentrations of this transmitter in the rat stomach, in-vivo and in real time, with applications in pharmacology and physiology. METHODS: Wistar rats fasted for 12h. Then, the control group was given an intragastrical dose of saline. l-Cysteine (50mg/kg) or dl-propargylglycine (50mg/kg) were administered to the test groups to modify the H2S levels. Ranitidine (50mg/kg), omeprazole (40mg/kg) or carbenoxolone (30mg/kg) were used as reference anti-ulcer drugs. Thirty minutes later, the electrode was inserted in the middle of the stomach cavity of the anesthetized animals. The basal levels of H2S were recorded every 5min for 30min. Next, gastric lesions were induced with pure ethanol, and the recording continued for 30 additional minutes. RESULTS: The exogenous administration of an H2S precursor (l-cysteine) increased the level of this gasotransmitter whereas dl-propargylglycine, a selective inhibitor of the enzyme cystathionine γ lyase, reduced the total concentration of H2S. The administration of carbenoxolone, a gastroprotective, increased the total amount of H2S. However, the administration of the anti-secretors omeprazole and ranitidine did not modify the total concentration of H2S. DISCUSSION: This work provides the basis for a real-time analysis of the changes in-vivo of the gasotransmitter H2S in the normal and injured stomach and the exploration of the effect of drugs on the regulation of H2S.

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According to the Peruvian legislation, salt for human consumption should contain 200-250 mg F/kg, but there is limited data showing whether this requirement is being accomplished. Aim: In this pilot study, we evaluated the fluoride concentration in samples of salt marketed in Lima, Peru, using a standardized protocol with ion-specific electrode by direct method (ISE). Methods: Seven 1 kg salt packages of four brands were purchased in two supermarkets of Lima. Six aliquots of each package were weighed and dissolved in the proportion of 0.025 g/mL of water. Duplicates of 1.0 mL of these solutions were mixed with 1.0 mL of TISAB II and fluoride concentration was determined with ISE calibrated with standards fluoride solutions ranging from 0.25 to 16.0 µg F/mL. The ionic strength of the standards was adjusted with p.a NaCL (25 mg/mL). In addition, triplicates of 15 g of each salt package were fractionated in a set of sieves (0.590 to 0.177 mm) to determine the homogeneity of fluoride concentration in salt. Results: In four packages the mean fluoride (mean±SD,n=6) concentration (mg F/kg) was in agreement to the Peruvian regulation (214.5±10.4; 221.8±14.3; 226.9±19.1 and 237.2±52.0 mg F/kg), but in 3 packages it was lower (145.2±7.9; 145.7±23.3 and 158.4±20.6 mg F/kg). Variability in fluoride concentration was observed within the same brand and among brands. Also, the fluoride concentration was not homogeneous in none of the salt samples, ranging from 72.0 to 1449.7 mg F/kg. Conclusion: The findings suggest that the manufacturing and sanitary surveillance of fluoridated salt in Peru should be improved

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OBJECTIVES: To assess the fluoride (F) content in commercially available milk formulae in Brazil and to estimate the F intake in children from this source in the first year of life. METHODS: Samples of cow's milk (n = 51), infant formulae (n = 15), powdered milk (n = 13), and soy-based products (n = 4) purchased in Araçatuba (Brazil) had their F content measured using an ion-specific electrode, after hexamethyldisiloxane-facilitated diffusion. Powdered milk and infant formulae were reconstituted with deionized water, while ready-to-drink products were analyzed without any dilution. Using average infant body masses and suggested volumes of formula consumption for infants 1-12 months of age, possible F ingestion per body mass was estimated. Data were analyzed by descriptive analysis. RESULTS: Mean F content ranged from 0.02 to 2.52 mg/L in all samples. None of the cow's milk provided F intake higher than 0.07 mg/kg. However, two infant formulae, one powdered milk, and one soy-milk led to a daily F intake above the suggested threshold for fluorosis when reconstituted with deionized water. Assuming reconstitution of products with tap water at 0.7 ppm F, two infant formulae, five powdered milk, and four soymilks led to daily F intake ranging from 0.108 to 0.851 mg/kg. CONCLUSIONS: The results suggest that the consumption of some brands of infant formulae, powdered milk, and soy-based milk in the first year of age could increase the risk of dental fluorosis, reinforcing the need for periodic surveillance of the F content of foods and beverages typically consumed by young children.

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