Effect of exogenous Ca on the physiology and growth indicators of pakchoi under foliar and root fluorine stress.

Fluorine (F) is not an essential element for vegetation and excessive F can be phytotoxic to plant growth, which can cause fluorosis to human beings by ingesting F-contaminated plant. Although there have been some studies focusing on the toxicity of F to plants and the retarding effect of Ca to F-stress plant, atmospheric F contamination to vegetation and the role of the application of foliar Ca are scantly reported. This study investigated several biochemical parameters to evaluate F toxicity under both F-exposure (root and leaf F-exposure) and the remedial effects of foliar Ca. The results showed that F concentration of pakchoi leaves was correlated with exogenous F level positively in both foliar and root F-exposure series, and F concentration of pakchoi roots was only changed under root F-exposure treatments. Ca supplement (0.5 g/L and 1 g/L) significantly decreased plant F concentration. Both F-exposure treatments caused lipid peroxidation in plants and exogenous Ca alleviated the toxicity of F to pakchoi. Meanwhile, chlorophyll-a concentration was decreased by foliar and root F, whereas chlorophyll-b concentration was only affected by foliar F, and chlorophyll-a concentration could be elevated by exogenous Ca but chlorophyll-b could not. It was concluded that both atmospheric and root F can impair pakchoi growth and disturb photosynthesis, and foliar Ca showed an ameliorative effect to F toxicity of pakchoi through alleviating chlorophyll decomposition, increasing protein content and alleviating oxidative damage.

A comprehensive review on endemic and experimental fluorosis in sheep: Its diverse effects and prevention.

Fluoride is a natural element widely distributed in the environment and plays an important role in the growth of humans and animals. However, in many species, high concentrations of fluoride induce several problems, such as dental, skeletal, and non-skeletal fluorosis. Sheep living in endemic areas are sensitive to the chronic toxicity of fluoride, and they have been found to suffer not only from teeth and bone problems but also from other organs. Studies indicating the chronic harmful effects of fluoride on teeth, bones, blood biochemical parameters, kidney, liver, heart, reproductive system and growth in sheep have been clearly summarized in this review. Besides, this work also includes updated progress in terms of prevention or reduction of fluoride toxicity in this species.

Fluorine in the environment in an endemic fluorosis area in Southwest, China.

Soils in large areas of China are enriched in fluorine (F). The present study analyzed F concentrations in cultivated soil, water, chemical fertilizer, and human hair, and metal concentrations in soils from an endemic fluorosis area in Southwest, China. In order to reveal the effects of industry on F concentration in the environment, 3 towns mainly with agriculture production and another 3 towns with developed phosphorus chemical industry in a same city were selected for sample collection. The total F concentrations of the 277 surface agricultural soil samples were 378.79-1576.13 µg g-1, and F concentrations of nearly 95% of the soil samples were higher than the Chinese average topsoil F concentration (480 µg g-1). Only a small fraction (0.75%) of total F was water soluble. The average total F, water soluble F, Ca, Cr, Fe, K, Mn, Rb, and Sr concentrations in soil samples from towns with intensive industry were higher than those from towns mainly with agriculture. Significant correlations were found between soil pH with total F (p < 0.01) and with water soluble F concentration (p < 0.1). Low F concentrations (<0.5 mg L-1) were found in irrigation water, well water and tap water in a town where the industry is dense. The phosphorus fertilizer and compound fertilizer had hundreds of times of contribution to soil F increment than the nitrogen fertilizer and potassium fertilizer. Nearly half percent of F in the human hair samples was of exogenic origin. Based on soil ingestion pathway, the health risk for adults exposure to F in soils was acceptable, however, F may pose possible health risks to children in high F concentration areas.

Health risk assessment of fluorine in fertilizers from a fluorine contaminated region based on the oral bioaccessibility determined by Biomimetic Whole Digestion-Plasma in-vitro Method (BWDPM).

Due to potential adverse effects of excessive fluorine (F), interests regarding considerable accumulation of F in agricultural soils from application of fertilizers are increasing continually. However, less detailed information of hazard and risk of F in fertilizers to human directly by hand-to-mouth pathway can be obtained. Herein, the bioaccessibility of F (Fbio) in fertilizers is determined by Biomimetic Whole Digestion-Plasma in-vitro Method (BWDPM), which is developed to detect the behaviour of bioaccessible F in both the whole digestive system and plasma for the first time. Observations of higher Fbio in small intestinal phases (4.35-56.33%), large intestine (1.01-40.52%) and plasma (8.07-66.70%) yielded them as the major phases which are faced with higher exposure risk of F. Compared with phosphate fertilizer, more bioaccessible F was observed in compound fertilizer. Some studied factors, such as sweat and food, yield insignificant influences on Fbio, whereas can affect the exposure estimations of F considerably. Exposure risks based on Fbio of fertilizers should be highly concerned, especially the occupational exposure to local farmers. In a word, more explicit and realistic information of the potential risk of F on human health could be obtained by the introduction of Fbio.

Differential Expression of miRNAs in the Hippocampi of Offspring Rats Exposed to Fluorine Combined with Aluminum during the Embryonic Stage and into Adulthood.

A previous study from our team found that continuous exposure to fluorine combined with aluminum (FA) impaired the neurobehavioral reflexes, spatial learning, and memory of offspring rats. To date, the specific mechanisms for these changes are unclear. Here, high-throughput sequencing was utilized to analyze the microRNA (miRNA) profile of the hippocampi in the offspring of rats exposed to FA during the embryonic stage and into adulthood through tap water supplemented with NaF and AlCl3 at concentrations of (0, 0); (60, 600); (120, 600); and (240, 600) mg/L, respectively. qRT-PCR was performed to validate the reliability of the sequence data. Twenty differentially expressed miRNAs were selected for further analysis using bioinformatics tools. Several genes related to neuromodulation were found to be regulated by miR-10a-5p, miR-34b-5p, and miR-182, which might be harmful to normal nerve function. The protein levels of brain-derived neurotrophic factor (BDNF) and tyrosine receptor kinase B (TrkB) in hippocampus were markedly downregulated. These data suggest that miR-10a-5p, miR-34b-5p, and miR-182 and BDNF-TrkB signaling pathway are involved in mechanisms of hippocampal damage in the offspring of rats exposed to FA. HIGHLIGHTS: • Multiple miRNAs were significantly differentially expressed in offspring rat hippocampus after fluorine combined with aluminum (FA) exposure. • Twenty differentially expressed miRNAs might mediate FA-induced developmental neurotoxicity. • MiR-10a-5p, miR-34b-5p, and miR-182 were closely related to neurotoxic signaling of FA. • The BDNF-TrkB learning and memory-associated pathway was downregulated in the hippocampus after FA exposure.

A mini review of fluoride-induced apoptotic pathways.

Fluorine or fluoride can have toxic effects on bone tissue and soft tissue at high concentrations. These negative effects include but not limited to cytotoxicity, immunotoxicity, blood toxicity, and oxidative damage. Apoptosis plays an important role in fluoride-induced toxicity of kidney, liver, spleen, thymus, bursa of Fabricius, cecal tonsil, and cultured cells. Here, apoptosis activated by high level of fluoride has been systematically reviewed, focusing on three pathways: mitochondrion-mediated, endoplasmic reticulum (ER) stress-mediated, and death receptor-mediated pathways. However, very limited reports are focused on the death receptor-mediated apoptosis pathways in the fluoride-induced apoptosis. Therefore, understanding and discovery of more pathways and molecular mechanisms of fluoride-induced apoptosis may contribute to designing measures for preventing fluoride toxicity.

Tolerance strategies of two Mediterranean native xerophytes under fluoride pollution in Tunisia.

A field study was conducted along a fluorine gradient of soil pollution in Tunisia from Gabes, the most polluted site, to Smara, the reference site. Variations of fluoride (F) concentrations in soils were detected over 1 year in Gabes, Skhira, and Smara. F concentrations in the aerial part of two native plant species, i.e., Erodium glaucophyllum and Rhanterium suaveolens, were above the usual background concentrations. Bioaccumulation factors ranged from 0.08 to 1.3. With F concentrations in aerial parts up to 355 mg kg-1, both species may be described as F accumulators. Both species showed an earlier vegetative growth in Gabes than in Smara. However, some difference between their strategies could be observed, i.e., E. glaucophyllum shortening the period of its vegetative growth with an escape strategy and R. suaveolens decreasing its ratio of alive/dead parts potentially lowering the F toxicity by storage in dead cells. However, at a tissue level, mechanisms of tolerance were similar. Leaf section micrographs of both species showed a higher calcium accumulation in leaf midveins at Gabes than at Smara, confirming the role of calcium in plant F tolerance strategies.

MiR-132, miR-204 and BDNF-TrkB signaling pathway may be involved in spatial learning and memory impairment of the offspring rats caused by fluorine and aluminum exposure during the embryonic stage and into adulthood.

Fluorine and aluminium are nervous system poisons, but it remains unclear whether combined fluorine and aluminium exposure damages spatial learning and memory and, if so, by what mechanism. This study showed that exposure to fluorine and aluminium, either alone or combined, during the embryonic stage and into adulthood caused spatial learning and memory impairment in offspring rats; its mechanism may be associated with increases in miR-132 and miR-204 expression and downregulation of the BDNF-TrkB pathway in the hippocampus. The effects of F were obvious, but the effects of Al were slight. There were antagonistic effects between F and Al, with Al reducing the toxicity of F.

Effects of fluorine on crops, soil exoenzyme activities, and earthworms in terrestrial ecosystems.

Fluorine can flow into the environment after leakage or spill accidents and these excessive amounts can cause adverse effects on terrestrial ecosystems. Using three media (filter paper, soil, and filter-paper-on-soil), we investigated the toxic effects of fluorine on the germination and growth of crops (barley, mung bean, sorghum, and wheat), on the activities of soil exoenzymes (acid phosphatase, arylsulfatase, fluorescein diacetate hydrolase, and urease) and on the survival, abnormality, and cytotoxicity of Eisenia andrei earthworms. The germination and growth of crops were affected by fluorine as exposure concentration increased. The activities of the four enzymes after 0-, 3-, 10-, and 20-day periods varied as exposure concentration increased. According to in vivo and in vitro earthworm assays, E. andrei mortality, abnormality, and cytotoxicity increased with increasing fluorine concentration. Overall, fluorine significantly affected each tested species in the concentration ranges used in this study. The activities of soil exoenzymes were also affected by soil fluorine concentration, although in an inconsistent manner. Albeit the abnormally high concentrations of fluorine in soil compared to that observed under natural conditions, its toxicity was much restrained possibly due to the adsorption of fluorine on soil particles and its combination with soil cations.

Knowledge of Brazilian Dental Students about the Use of Conventional Fluoride Dentifrices for Preschool Children from Zero to Six Years Old

Objective: To verify the knowledge of dental students about the correct use of fluoride dentifrices above 1000 pmm fluorine for children aged 0-6 years old. Material and Methods: This is a cross-sectional study in which self-administered questionnaires were administered to 355 dental students from sixth to ninth or tenth graduation period. The questionnaires included questions regarding knowledge of the need to use, concentration, amount, frequency and potential adverse effects of the use of conventional fluoride dentifrices above 1000 ppm of fluorine by children up to six years of age, as well as the mechanism of action and the method of using fluorides that has the most scientific evidence. A descriptive analysis of data was performed. Results: 83.1% of students reported receiving content on the use of fluoride dentifrices in early childhood. Most students consider the use of fluoride dentifrice as important for the age group from zero to three years (73.8%) and from three to six years (96.4%). Only 17.7% would indicate fluoride toothpaste above 1000 ppm fluoride for children from zero to three years and 40.6% for three to six years. 76.9% believe that the amount of ideal refers to a grain of rice (0-3 years) and 61.7% of pea grain (3-6 years). 43.4% of students believe that fluoride dentifrices as an adverse effect the potential to cause fluorosis independent of concentration. Conclusion: The students evaluated were misleading about the fluoride concentration of the dentifrices indicated for children up to six years of age; on the toxicity of fluorine; action mechanism of fluorides and the scientific method of greater scientific evidence on caries disease. Failures in training and need to update fluoride contents to be taught to future dentistry professionals are evident.

Pharmaco-toxicological effects of the novel third-generation fluorinate synthetic cannabinoids, 5F-ADBINACA, AB-FUBINACA, and STS-135 in mice. In vitro and in vivo studies.

INTRODUCTION: 5F-ADBINACA, AB-FUBINACA, and STS-135 are 3 novel third-generation fluorinate synthetic cannabinoids that are illegally marketed as incense, herbal preparations, or research chemicals for their psychoactive cannabis-like effects. METHODS: The present study aims at investigating the in vitro and in vivo pharmacological activity of 5F-ADBINACA, AB-FUBINACA, and STS-135 in male CD-1 mice, comparing their in vivo effects with those caused by the administration of Δ9 -THC and JWH-018. In vitro competition binding experiments revealed a nanomolar affinity and potency of the 5F-ADBINACA, AB-FUBINACA, and STS-135 on mouse and human CB1 and CB2 receptors. Moreover, these synthetic cannabinoids induced neurotoxicity in murine neuro-2a cells. RESULTS: In vivo studies showed that 5F-ADBINACA, AB-FUBINACA, and STS-135 induced hypothermia; increased pain threshold to both noxious mechanical and thermal stimuli; caused catalepsy; reduced motor activity; impaired sensorimotor responses (visual, acoustic, and tactile); caused seizures, myoclonia, and hyperreflexia; and promoted aggressiveness in mice. Behavioral and neurological effects were fully prevented by the selective CB1 receptor antagonist/inverse agonist AM 251. Differently, the visual sensory response induced by STS-135 was only partly prevented by the AM 251, suggesting a CB1 -independent mechanism. CONCLUSIONS: For the first time, the present study demonstrates the pharmaco-toxicological effects induced by the administration of 5F-ADBINACA, AB-FUBINACA, and STS-135 in mice and suggests their possible detrimental effects on human health.

Effect of Quaternary Ammonium Salts with Fluorine Atoms on Selected Weed Species.

This study investigated the effects of four structurally different quaternary ammonium salts (QASs), i.e., tetrabutylammonium tetrafluoroborate [TBA][BF4], tetrahexylammonium tetrafluoroborate [THA][BF4], tetrabutylammonium hexafluorophosphate [TBA][PF6], and tetrahexylammonium hexafluorophosphate [THA][PF6], on the growth and development of three weed species: gallant soldier (Galinsoga parviflora Cav.), white goosefoot (Chenopodium album L.) and common sorrel (Rumex acetosa L.). The examined compounds were applied in the form of foliar spraying and soil application. Strong herbicidal properties of the examined compounds were demonstrated in case of their soil application. Growth inhibition of plant shoots and roots was greater with soil application than with foliar treatment. The strongest herbicidal activity of compounds was demonstrated with [TBA][BF4] have demonstrated [TBA][BF4] and [TBA][PF6] applied to the soil, while [THA][BF4] demonstrated the weakest herbicidal action. The increased concentration of applied QASs caused a decrease in the assimilation pigments, change in dry weight content and inhibition of length of shoots and roots.

Synthesis and biological activity of the novel indanedione anticoagulant rodenticides containing fluorine.

Here, 3 fluorinated intermediates of drug were synthesized: (M1), (M2), (M3). Three new anticoagulant rodenticides were designed which were based on 4-hydroxycoumarin or 1,3-indandione, added acute toxicity groups containing fluorine. The structures of synthesized compounds were analyzed and proved by FT-IR spectroscopy and 1H nuclear magnetic resonance (1H-NMR). The compounds were also evaluated for their anticoagulant and acute biologic activity. In addition, both the acute orally toxicity and the feeding indexes of R1 and R2 were tested. The result of the experiment proved that the new synthesis of 1, 3 - indan diketone for maternal new anticoagulant rodenticide can replace the current 4 - hydroxyl coumarin as the mother of the second generation anticoagulant rodenticide and 1, 3 - indan diketone for maternal new anticoagulant rodenticides will have a good development prospect.

Evaluación del riesgo tóxico por la presencia de fluoruro en aguas de bebida envasada consumidas en Canarias / Toxic risk assessment of fluoride presence in bottled water consumption in the Canary Islands

Introducción: el flúor, como hormetina, es necesario en el organismo para evitar las caries, pero en cantidades excesivas puede llevar a efectos tóxicos adversos como la fluorosis dental o la fluorosis invalidante. Así, será importante no sobrepasar de forma crónica las IDR (Ingestas Diarias Recomendadas) para cada rango de edad y sexo. Se asume que la principal fuente de aporte de fluoruros es el agua. Objetivos: establecer las concentraciones de fluoruro en determinadas marcas de agua envasada que se consumen en Canarias, para renovar los datos ya desactualizados, y hacer la correspondiente evaluación del riesgo tóxico. Método: se han utilizado 25 muestras de siete marcas registradas y comercializadas diferentes, siendo analizadas mediante determinación potenciométrica con electrodo ion selectivo de fluoruro. Resultados: todas las marcas de agua analizadas cumplen con los criterios de calidad según la legislación actual española, ninguna puede considerarse 'agua fluorada' y todas se pueden usar en la preparación de alimentos infantiles. Además, según las ingestas diarias de agua recomendadas por la EFSA para cada rango de edad, no se supera la IDR para ningún individuo mayor de cuatro años ni para ninguna de las marcas de agua analizadas. Conclusiones: las aguas envasadas producidas en Canarias tienen niveles de fluoruro similares a las producidas en la península (todas en un rango de 0,24 a 0,62 mg/L). Los individuos sobre los que recaen las restricciones más amplias de consumo de agua son los menores de un año, pero en cualquier caso, a medida que el individuo crece va aumentando la permisibilidad del aporte de fluoruros (aumenta hasta los 19 años) y, por tanto, aumenta la variedad de aguas envasadas que se pueden consumir sin superar la IDR. En ciertos lugares de la Comunidad Autónoma Canaria sería recomendable consumir agua envasada respecto al agua de abastecimiento público (AU)

Introduction: fluorine, as an hormetin, is necessary in the organism to avoid caries; but large amounts can produce toxic side effects such as dental fluorosis or skeletal fluorosis. Thus, it is important not to exceed chronically the RDIs (Recommended Daily Intakes) per each age and sex range. It is assumed that the main fluoride source is water. Objectives: to establish fluoride concentrations at certain bottled water brands being consumed in the Canary Islands for renovating the outdated data, and to evaluate the subsequent toxic risk. Method: 25 samples have been used from 7 different registered and commercialized brands, being analyzed by a potentiometer with a fluoride ion selective electrode. Results: all analyzed water brands satisfied quality criteria according to the Spanish law, no one could be considered 'fluorinated water' and all of them could be used to prepare baby food. Moreover, according to the recommended daily water intake by the EFSA per each age range, no water analyzed brand could exceed the RDI for no one over 4 years old. Conclusions: the bottled waters that are produced in the Canary Islands have similar fluoride concentrations than those that are produced in the Peninsula (all of them have a data range between 0.24 and 0.62 mg/L). The individuals who have more water restrictions are those under 1 year old; but in any case, while the child is growing up, the levels of fluoride consumption can be higher (until 19 years old) and therefore the water brands variety that can be drunk, without exceeding the RDI, is also higher. In some places in the Canary Islands, it would be advisable to consume bottled water in place of tap water (AU)

Coal utilization in China: environmental impacts and human health.

Coal is one of the major energy resources in China, accounting for approximately 70 % of primary energy consumption. Many environmental problems and human health risks arise during coal exploitation, utilization, and waste disposal, especially in the remote mountainous areas of western China (e.g., eastern Yunnan, western Guizhou and Hubei, and southern Shaanxi). In this paper, we report a thorough review of the environmental and human health impacts related to coal utilization in China. The abundance of the toxic trace elements such as F, As, Se, and Hg in Chinese coals is summarized. The environmental problems (i.e., water, soil, and air pollution) that are related to coal utilization are outlined. The provenance, distributions, typical symptoms, sources, and possible pathways of endemic fluorosis, arsenism, and selenosis due to improper coal usage (briquettes mixed with high-F clay, mineralized As-rich coal, and Se-rich stone coal) are discussed in detail. In 2010, 14.8, 1.9 million, and 16,000 Chinese people suffered from dental fluorosis, skeletal fluorosis, and arsenism, respectively. Finally, several suggestions are proposed for the prevention and treatment for endemic problems caused by coal utilization.

Influences of coal mining water irrigation on the maize losses in the Xingdong Mine area, China.

In 2008, a maize underproduction disaster occurred in the Xianyu village after irrigation using the coal mining water from the Xingdong Mine, China. This disaster resulted in about 40 hectare maize underproduction and 20 hectare total loss of the maize yields. In order to study the reason, a total of 25 soil, water and plant samples were taken from the study area. These samples were analysed by inductively coupled plasma mass spectrometry and ion chromatography. The results indicate that the contents of both water-soluble fluorine and total fluorine are very high and resulting of maize underproduction and total loss of production. The possible pollution sources of fluorine in the study area could be from the coal mine water used for irrigation and glass chemical factory near the study area.

Mechanisms of intracellular defense and activity of free radical oxidation in rat myocardium in the dynamics of chronic fluorine intoxication.

The mechanisms of intracellular defense and activity of free radical oxidation in the myocardium were studied in the dynamics of chronic fluorine intoxication. At the early stages of fluorine intoxication (day 3-week 3), the concentrations of defense proteins HIF-1α, HSC73, and HOx-2 and activity of the main metabolic enzymes increased, which promoted maintenance of cardiomyocyte structure and function at the normal physiological level. At late stages of fluorine intoxication (weeks 6 and 9), metabolic changes in the myocardium attest to high strain of the adaptive mechanisms.

Photoinactivation of Escherichia coli by sulfur-doped and nitrogen-fluorine-codoped TiO2 nanoparticles under solar simulated light and visible light irradiation.

Titanium dioxide (TiO2) is one of the most widely used photocatalysts for the degradation of organic contaminants in water and air. Visible light (VL) activated sulfur-doped TiO2 (S-TiO2) and nitrogen-fluorine-codoped TiO2 (N-F-TiO2) were synthesized by sol-gel methods and characterized. Their photoinactivation performance was tested against Escherichia coli under solar simulated light (SSL) and VL irradiation with comparison to commercially available TiO2. Undoped Degussa-Evonik P-25 (P-25) and Sigma-TiO2 showed the highest photocatalytic activity toward E. coli inactivation under SSL irradiation, while S-TiO2 showed a moderate toxicity. After VL irradiation, Sigma-TiO2 showed higher photoinactivation, whereas S-TiO2 and P-25 showed moderate toxicity. Oxidative stress to E. coli occurred via formation of hydroxyl radicals leading to lipid peroxidation as the primary mechanism of bacterial inactivation. Various other biological models, including human keratinocytes (HaCaT), zebrafish liver cells (ZFL), and zebrafish embryos were also used to study the toxicity of TiO2 NPs. In conclusion, N-F-TiO2 did not show any toxicity based on the assay results from all the biological models used in this study, whereas S-TiO2 was toxic to zebrafish embryos under all the test conditions. These findings also demonstrate that the tested TiO2 nanoparticles do not show any adverse effects in HaCaT and ZFL cells.

Myeloperoxidase activity and its corresponding mRNA expression as well as gene polymorphism in the population living in the coal-burning endemic fluorosis area in Guizhou of China.

The myeloperoxidase (MPO) activity and its corresponding mRNA expression as well as gene polymorphism were investigated in the population who live in the endemic fluorosis area. In the study, 150 people were selected from the coal-burning endemic fluorosis area and 150 normal persons from the non-fluorosis area in Guizhou province of China. The blood samples were collected from these people. The activity of MPO in the plasma was determined by spectrophotometer; the expression of MPO mRNA was measured by employing real-time polymerase chain reaction; DNAs were extracted from the leucocytes in blood and five SNP genotypes of MPO promoter gene detected by a multiplex genotyping method, adapter-ligation-mediated allele-specific amplification. The results showed that the MPO activity and its corresponding mRNA in blood were significantly increased in the population living in the area of fluorosis. The different genotype frequencies of MPO, including -1228G/A, -585T/C, -463G/A, and -163C/T, and the three haplotypes with higher frequencies, including -163C-463G-585T-1228G-1276T, -163C-463G-585T-1228G-1276C, and -163C-463G-585T-1228A-1276T, were significantly associated with fluorosis. The results indicated that the elevated activity of MPO induced by endemic fluorosis may be connected in mechanism to the stimulated expression of MPO mRNA and the changed gene polymorphism.

Riscos do uso do dentifrício fluoretado na prevenção e controle de cárie na primeira infância / Risks of fluoride dentifrice in the prevention and control of dental caries in the primary childhood

Dentifrício fluoretado tem sido considerado responsável pelo declínio de carie dentária ocorrida tanto em países desenvolvidos quanto nos em desenvolvimento, como o Brasil. Entretanto, como as crianças involuntariamente ingerem certa quantidade de dentifrício quando escovam os dentes, há preocupação com a fluorose decorrente. Entretanto, o risco em potencial do dentifrício provocar fluorose tem sido estimado com base na dose de ingestão de fluoreto, considerando como limite a dose de 0,07 mg F/dia/kg de peso e não na fluorose decorrente. A dose de ingestão de fluoreto por dentifrícios tem sido superestimada, porque não considera quanto do fluoreto ingerido está biodisponível para ser absorvido e provocar fluorose. A falta de associação entre dose de ingestão e fluorose tem sidomostrada experimentalmente e comprovada epidemiologicamentepelo grau não preocupante de fluorose encontrado, possibilitandoratificar a importância da recomendação do uso de dentifríciofluoretado para o controle de cárie, sem grandes preocupações compossíveis efeitos colaterais.

Fluoride toothpaste has been considered responsible for the cariesdecline which occurred either in developed or in developing countries, such as Brazil. However, since children inadvertently ingest a certain amount of toothpaste while brushing their teeth, there is a concern on the subsequent fluorosis. Nevertheless, the potential risk of fluorosis from fluoride toothpaste has been overestimated based on the dose offluoride ingested, considering as limit the dose of 0.07 mg F/kg bodyweight/day, and not on the actual fluorosis outcome. The dose offluoride ingestion from toothpastes has been overestimated because Itdoes not consider how much of fluoride is bioavailable to be absorbed and cause fluorosis. The lack of association between ingestion dose and fluorosis has been shown experimentally and observed epidemiologically by the mild degree of fluorosis found, which enables us to ratify the importance of the recommendation of fluoride toothpaste for caries control in young children, with few concerns on possible side effects.