TiF4 and NaF varnishes as anti-erosive agents on enamel and dentin erosion progression in vitro

Objective This study assessed the effect of fluoride varnishes on the progression of tooth erosion in vitro. Material and Methods: Forty-eight enamel and 60 root dentin samples were previously demineralized (0.1% citric acid, pH 2.5, 30 min), leading to a baseline and erosive wear of 12.9 and 11.4 µm, respectively. The samples were randomly treated (6 h) with a 4% TiF4 varnish (2.45%F-, pH 1.0), a 5.42% NaF varnish (2.45%F-, pH 5.0), a placebo varnish and no varnish (control). The samples were then subjected to erosive pH cycles (4x90 s/day in 0.1% citric acid, intercalated with artificial saliva) for 5 days. The increment of the erosive tooth wear was calculated. In the case of dentin, this final measurement was done with and without the demineralized organic matrix (DOM). Enamel and dentin data were analyzed using ANOVA/Tukey’s and Kruskal-Wallis/Dunn tests, respectively (

Exposição perinatal ao chumbo: efeitos da associação de diferentes condições estressogênicas sobre a reatividade vascular e o comportamento de ratos recém-desmamados e adultos

O sistema de estresse coordena a resposta adaptativa ao estímulo estressor e desempenha papel importante na manutenção da homeostase frente a condições estressogênicas. A ativação desse sistema leva a alterações comportamentais e periféricas que aumentam a habilidade do organismo de se adaptar e, portanto, aumentam as suas chances de sobrevivência. Respostas inadequadas ou prolongadas aos estressores podem prejudicar o crescimento e o desenvolvimento e resultar numa grande variedade de desordens de natureza endócrina, metabólica, cardiovascular ou comportamental. A exposição ao estresse determina respostas adaptativas tanto sobre a reatividade vascular quanto sobre o comportamento de ratos. Ainda, o comportamento de ratos não estressados ou submetidos ao estresse pode sofrer influência de experiências estressogênicas perinatais. Finalmente, a resposta ao estresse pode ser alterada por estados patológicos particulares, como hipertensão, intoxicação por metais pesados como o chumbo (Pb), entre outros fatores. Os objetivos foram investigar: 1) as alterações na resposta vascular e no comportamento de ratos jovens e adultos submetidos ou não ao estresse agudo e/ou crônico em diferentes fases do desenvolvimento; 2) se a habilidade em gerenciar o estresse difere entre proles submetidas ou não à intoxicação perinatal por Pb e 3) a participação do endotélio na resposta vascular adaptativa ao estresse em ratos intoxicados ou não. Foram realizadas curvas concentração-efeito à noradrenalina (NA) em aortas torácicas com (+E) e sem endotélio (-E), de ratos jovens (23 dias) e adultos (70 dias) intoxicados perinatalmente por Pb ou não e submetidos ou não ao estresse agudo de imobilização (IM, 2h imediatamente antes dos protocolos experimentais) e/ou crônico de separação materna (SM, 4h/dia por 3 semanas consecutivas). O comportamento dos animais...The stress response is subserved by the stress system which plays a key role in the maintenance of homeostasis. The human body and mind react to stress by activating a complex repertoire of physiologic and behavioral central nervous system and peripheral adaptive responses, which, if inadequate or excessive and/or prolonged, may affect personality developmental and behavior, and may have adverse consequences on physiologic functions, such as growth, metabolism, circulation and reproduction. The exposure to stressors may induce alterations in the cardiovascular system and behavior, which are related to adaptative processes that can be modified by previous exposure to environmental hazard like plumb or hypertension. The objective was to investigate: the alterations of both vascular reactivity and behavior of 23 days-old and 70 days-old rats exposed to lead during pregnancy and postnatal period and submitted or not to acute and chronic stress; and if the endothelium of intoxicated rats modulate the vascular adaptative response to stress. Concentration effect curves to noradrenaline were obtained in aorta, with and without endothelium of weaned and adult rats of rats exposed or not to Pb and submitted or not to acute (immobilization) or chronic stress (maternal separation, for 4h during 3 weeks), or both. The behavior was measured by open-field and elevated plus-maze. Pb exposed rats showed a decreased vascular reactivity to noradrenaline when submitted to acute stress or acute stress plus chronic one compared with weaned rats exposed to Pb but not to stress conditions. No reactivity alteration in the sensitivity to noradrenaline was observed in aorta with endothelium from weaned rats exposed to the different protocols. The exposure of non intoxicated rats to acute stress and chronic plus acute The exposure of non intoxicated rats to acute stress and chronic plus acute stress determined... (Complete abstract click electronic access below)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Perinatal lead exposure affects nitric oxide and cyclooxygenase pathways in aorta of weaned rats

Perinatal Pb exposure may modulate arterial tone through nitric oxide (NO) and cyclooxygenase products. To investigate this, Wistar dams received 1000 ppm of Pb or sodium acetate (control) in drinking water during pregnancy and lactation. Curves were constructed in phenylephrine-precontracted intact and/or denuded rings of thoracic aortas of weaned (23-day-old) male pups from their responses to N-omega-nitro-L-arginine methyl ester (L-NAME, NO synthase inhibitor) and ACh in the absence or presence of indomethacin (10(-5)M, cyclooxygenase inhibitor) or L-NAME (3 x 10(-7)M and 3 x 10(-4)M). Blood lead concentration and systolic blood pressure (SBP) were higher in intoxicated than control pups (blood lead mu g/dl: control < 3.0, Pb 58.7 +/- 6.5*; SBP mmHg: control 111.4 +/- 2.3, Pb 135.5 +/- 2.4*). In L-NAME-treated rings maximal responses increased in Pb-exposed rats, and were higher in intact than in denuded aortas (contraction [% of phenylephrine] intact: control 184.3 +/- 23.7, Pb 289.1 +/- 18.3*; denuded: control 125.1 +/- 4.5, Pb 154.8 +/- 13.3*). ACh-induced relaxation in intact aortas from Pb-exposed rats presented rightward shift in L-NAME presence (EC50 x 10(-7)M: control 1.32 [0.33-5.18], Pb 4.88 [3.56-6.69]*) but moved left under indomethacin (EC50 x 10(-7)M: control 8.95 [3.47-23.07], Pb 0.97 [0.38-2.43]*). *p < 0.05 significant relative to the respective control; N = 7-9. Endothelium removal abolished ACh-induced relaxation. Perinatal Pb exposure caused hypertension associated with alterations in the production and/or release of basal and stimulated endothelium-derived relaxing factors-NO and constricting cyclooxygenase products. These findings may help explain the contribution of NO and cyclooxygenase products to the etiology and/or maintenance of Pb-induced hypertension and could ultimately lead to therapeutic advantages in plumbism

Estimated Dietary Fluoride Intake by 24-Month-Olds from Chocolate Bars, Cookies, Infant Cereals, and Chocolate Drinks in Brazil

The use of fluoride (F) in the prevention of dental caries is established. However, a high amount of F intake during tooth development can cause dental fluorosis The aim of this study was to analyze variations in F concentrations in chocolate bars (CB), chocolate cookies (CC), infant cereals (IC), and chocolate milk drinks (CD) to determine the daily intake of F from different sources by children at the age of risk for developing dental fluorosis. Distinct brands of CB, CC, IC, and CD were analyzed. Fluoride was separated by hexamethyldisiloxane-facilitated diffusion. Analysis was made in triplicate with an F ion-specific electrode. F ingestion (mg/kg body weight) was evaluated with the suggested consumption (0.05–0.07 mg/kg/day) for children aged 24 months (12 kg). The concentrations for all the analyzed products ranged from 0.025 to 1.827 µg/g F. The mean (range) F concentrations were CB= 0.210 ± 0.205 µg/g (0.073–0.698, n = 8), CC = 0.366 ± 0.416 µg/g (0.320–1.827, n = 9), IC = 0.422 ± 0.395 µg/g (0.073–1.061, n = 5), and CD = 0.169 ± 0.170 µg/mL (0.025–0.443, n = 12). The products that had the highest concentration in the categories CB, CC, IC, and CD, respectively, were Nescau-Ball (0.698 µg/g), Passatempo (1.827 µg/g), Milnutri (1.061 µg/g), and Toddynho (0.443 µg/mL). The consumption of only one unit of Toddynho (CD) is equivalent to more than 11% of the maximum suggested daily intake for a 24-month-old child (0.07 mg/kg body weight). When one product from each category is consumed together only once a day, this consumption is equivalent to approximately 24% of the suggested daily intake of fluoride for a 24-month-old child. The presence of high levels of fluoride in certain products suggests that they play a significant role in overall fluoride intake. It is crucial to closely monitor the fluoride content of food and drinks that are consumed by children who are at risk for dental fluorosis, and for product labels to clearly display the fluoride concentrations

Evaluation of fluoride release from experimental TiF4 and NaF varnishes in vitro

Fluoride varnishes play an important role in the prevention of dental caries, promoting the inhibition of demineralization and the increase of remineralization. Objective: This study aimed to analyze the amount of fluoride released into water and artificial saliva from experimental TiF4 and NaF varnishes, with different concentrations, for 12 h. Material and Methods: Fluoride varnishes were applied on acrylic blocks and then immersed in 10 ml of deionized water and artificial saliva in polystyrene bottles. The acrylic blocks were divided in seven groups (n=10): 1.55% TiF4 varnish (0.95% F, pH 1.0); 3.10% TiF4 varnish (1.90% F, pH 1.0); 3.10% and 4% TiF4 varnish (2.45% F, pH 1.0); 2.10% NaF varnish (0.95% F, pH 5.0); 4.20% NaF varnish (1.90% F, pH 5.0); 5.42% NaF varnish (2.45% F, pH 5.0) and control (no treatment, n=5). The fluoride release was analyzed after 1/2, 1, 3, 6, 9 and 12 h of exposure. The analysis was performed using an ion-specific electrode coupled to a potentiometer. Two-way ANOVA and Bonferroni's test were applied for the statistical analysis (

TiF4 and NaF varnishes as anti-erosive agents on enamel and dentin erosion progression in vitro

Objective This study assessed the effect of fluoride varnishes on the progression of tooth erosion in vitro. Material and Methods: Forty-eight enamel and 60 root dentin samples were previously demineralized (0.1% citric acid, pH 2.5, 30 min), leading to a baseline and erosive wear of 12.9 and 11.4 &#181;m, respectively. The samples were randomly treated (6 h) with a 4% TiF4 varnish (2.45%F-, pH 1.0), a 5.42% NaF varnish (2.45%F-, pH 5.0), a placebo varnish and no varnish (control). The samples were then subjected to erosive pH cycles (4x90 s/day in 0.1% citric acid, intercalated with artificial saliva) for 5 days. The increment of the erosive tooth wear was calculated. In the case of dentin, this final measurement was done with and without the demineralized organic matrix (DOM). Enamel and dentin data were analyzed using ANOVA/Tukey&#8217;s and Kruskal-Wallis/Dunn tests, respectively (p<0.05). Results The TiF4 (mean&#177;s.d: 1.5&#177;1.1 &#181;m) and NaF (2.1&#177;1.7 &#181;m) varnishes significantly reduced enamel wear progression compared to the placebo varnish (3.9&#177;1.1 &#181;m) and control (4.5&#177;0.9 &#181;m). The same differences were found for dentin in the presence and absence of the DOM, respectively: TiF4 (average: 0.97/1.87 &#181;m), NaF (1.03/2.13 &#181;m), placebo varnish (3.53/4.47 &#181;m) and control (3.53/4.36 &#181;m). Conclusion The TiF4 and NaF varnishes were equally effective in reducing the progression of tooth erosion in vitro