Systematic review of epidemiological and toxicological evidence on health effects of fluoride in drinking water.

INTRODUCTION: Fluoride is a naturally occurring substance that is also added to drinking water, dental hygiene products, and food supplements for preventing dental caries. Concerns have been raised about several other potential health risks of fluoride. OBJECTIVE: To conduct a robust synthesis of evidence regarding human health risks due to exposure to fluoride in drinking water, and to develop a point of departure (POD) for setting a health-based value (HBV) for fluoride in drinking water. METHODS: A systematic review of evidence published since recent reviews of human, animal, and in vitro data was carried out. Bradford Hill considerations were used to weigh the evidence for causality. Several key studies were considered for deriving PODs. RESULTS: The current review identified 89 human studies, 199 animal studies, and 10 major in vitro reviews. The weight of evidence on 39 health endpoints was presented. In addition to dental fluorosis, evidence was considered strong for reduction in IQ scores in children, moderate for thyroid dysfunction, weak for kidney dysfunction, and limited for sex hormone disruptions. CONCLUSION: The current review identified moderate dental fluorosis and reduction in IQ scores in children as the most relevant endpoints for establishing an HBV for fluoride in drinking water. PODs were derived for these two endpoints, although there is still some uncertainty in the causal weight of evidence for causality for reducing IQ scores in children and considerable uncertainty in the derivation of its POD. Given our evaluation of the overall weight of evidence, moderate dental fluorosis is suggested as the key endpoint until more evidence is accumulated on possible reduction of IQ scores effects. A POD of 1.56 mg fluoride/L for moderate dental fluorosis may be preferred as a starting point for setting an HBV for fluoride in drinking water to protect against moderate and severe dental fluorosis. Although outside the scope of the current review, precautionary concerns for potential neurodevelopmental cognitive effects may warrant special consideration in the derivation of the HBV for fluoride in drinking water.

Potential risk of dental fluorosis associated with different baby formulas and water brands marketed in Spain.

Despite efforts to promote breastfeeding, many babies aged <6 months receive only baby formula reconstituted with bottled water. The intake of high levels of fluoride during amelogenesis has been associated with hypomineralization of the tooth enamel, with aesthetic and mechanical repercussions. The objective of this study was to determine the potential risk of dental fluorosis associated with baby formulas marketed in Spain. We measured 26 baby formulas frequently consumed in Spain; 17 brands for babies aged <6 months, 5 for those aged >6 months, and 4 ready-to-use brands. They were prepared with 4 types of water: distilled water and three brands of bottled water with different levels of fluoride. The fluoride concentration (mg/L or ppm F) was measured with an ion-specific electrode coupled to an ion analyzer. Each sample was prepared according to the manufacturer's instructions and analyzed in triplicate. A descriptive analysis was carried out. The minimum fluoride level found was 0.04 mg/L and the maximum was 1.02 mg/L. Considering the daily intake of these formulas, none exceeded the clinically-acceptable daily dose limit risk for fluorosis (0.07 mg F/day/kg body weight) when mixed with bottled water with a low level of fluoride (0.1 mg/L). However, when the same brands of formula were reconstituted with bottled water with a higher fluoride content (0.99 mg/L), they all exceeded the daily dose limit for the risk of fluorosis. As the potential risk of dental fluorosis associated with the formulas tested depends exclusively on the fluoride concentration of the waters used for reconstitution, formula packaging should contain a warning.

The fluorosis conundrum: bridging the gap between science and public health.

Fluorosis, a chronic condition brought on by excessive fluoride ingestion which, has drawn much scientific attention and public health concern. It is a complex and multifaceted issue that affects millions of people worldwide. Despite decades of scientific research elucidating the causes, mechanisms, and prevention strategies for fluorosis, there remains a significant gap between scientific understanding and public health implementation. While the scientific community has made significant strides in understanding the etiology and prevention of fluorosis, effectively translating this knowledge into public health policies and practices remains challenging. This review explores the gap between scientific research on fluorosis and its practical implementation in public health initiatives. It suggests developing evidence-based guidelines for fluoride exposure and recommends comprehensive educational campaigns targeting the public and healthcare providers. Furthermore, it emphasizes the need for further research to fill the existing knowledge gaps and promote evidence-based decision-making. By fostering collaboration, communication, and evidence-based practices, policymakers, healthcare professionals, and the public can work together to implement preventive measures and mitigate the burden of fluorosis on affected communities. This review highlighted several vital strategies to bridge the gap between science and public health in the context of fluorosis. It emphasizes the importance of translating scientific evidence into actionable guidelines, raising public awareness about fluoride consumption, and promoting preventive measures at individual and community levels.

Prevalence and risk factors of dental fluorosis among children aged 8-12 years in Shandong province of China.

This study was to investigate the prevalence and severity of children's dental fluorosis (DF) in Shandong and identified the potential risk factors for DF. A total of 87 villages in Shandong were investigated to calculate the prevalence of DF and Community Fluorosis Index (CFI) in 2018-2019. Six hundred and seventy children were enrolled to identify the potential risk factors using univariate and multivariate logistic regressions. Goodman-Kruskal Gamma was used to explore the factors related to the severity of DF. In 87 villages, 1249 of 8700 (14.36%) children still have DF. The prevalence of DF in most villages was below 40% in 2018-2019. Water fluorine concentration when selected for the study and urinary fluorine concentration were related to the risk of DF (P < 0.001). Some eating habits, like lower frequency of eating fresh vegetables, eggs, and beans, were associated with the risk of DF (P < 0.001). The high water fluorine concentration, and lower frequency of eating fresh vegetables, eggs, and beans were also related to the severity of DF (P < 0.001). DF in children in Shandong province is still a common endemic disease. This study tries to provide a useful guide for the prevention and control of DF.

Prevalence of Skeletal Fluorosis in Northern Tanzania: A Follow-Up Study.

OBJECTIVES: Skeletal fluorosis is a metabolic bone disease caused by excessive exposure to fluoride, predominantly through contamination of drinking water. This study aimed to identify all cases of skeletal fluorosis in Tindigani village situated in Northern Tanzania. This was done following changes in drinking water sources after a previous prevalence study in 2009 in this population. METHODS: In a door-to-door cross-sectional study of Tindigani village, a sample of residents was assessed for skeletal fluorosis and dental fluorosis. Diagnosis of skeletal fluorosis was based on pre-defined angles of deformity of the lower limbs. Dental fluorosis was diagnosed and graded using the Thylstrup and Fejerskov Index. Samples from current drinking water sources underwent fluoride analysis. RESULTS: Tindigani village had a population of 1,944 individuals. Of the 1,532 individuals who were screened, 45 had skeletal fluorosis, giving a prevalence of 3.3% (95% CI=2.4, 4.3). Dental fluorosis was present in 82.5% of those examined (95% CI=79.8, 85.3). Dental fluorosis was present in all individuals with skeletal fluorosis and at higher grades than in the rest of the population. Drinking water samples were collected from 28 sources. These included piped, surface, well, and borehole water sources. Fluoride concentrations ranged from 0.45-38.59 mg/L of fluoride. CONCLUSIONS: Skeletal fluorosis is an ongoing but preventable health problem in the current population. The delivery of sustainable low fluoride piped water to this community would be of clear health benefit. This has been addressed at a local level.

Fluoride Exposure and Skeletal Fluorosis: a Systematic Review and Dose-response Meta-analysis.

PURPOSE OF REVIEW: We performed a systematic review and meta-analysis on the relation between fluoride exposure and skeletal fluorosis (SF) using a novel statistical methodology for dose-response modeling. RECENT FINDINGS: Skeletal fluorosis, a major health issue that is endemic in some regions, affects millions of people worldwide. However, data regarding the dose-response relation between fluoride exposure and SF are limited and outdated. We included twenty-three studies in the meta-analysis. When comparing the highest versus the lowest fluoride category, the summary risk ratio (RR) for SF prevalence was 2.05 (95% CI 1.60; 2.64), with a value of 2.73 (95% CI 1.92; 3.90) for drinking water and 1.40 (95% CI 0.90; 2.17) for urinary fluoride. The RR by the risk of bias (RoB) was 2.37 (95% CI 1.56; 3.58) and 1.78 (95% CI 1.34; 2.36) for moderate and high RoB studies, respectively. The dose-response curve based on a one-stage cubic spline regression model showed an almost linear positive relation between exposure and SF occurrence starting from relatively low concentrations up to 5 mg/L and 2.5 mg/L, respectively, for water and urinary fluoride, with no substantial increase above this threshold. The RR for developing moderate-severe forms increases at 5.00 mg/L and 2.5 mg/L of water and urinary fluoride, respectively. Better-quality studies are needed to confirm these results, but greater attention should be given to water fluoride levels to prevent SF, in addition to the other potential adverse effects of fluoride exposure.

Community Water Fluoridation Levels To Promote Effectiveness and Safety in Oral Health - United States, 2016-2021.

Drinking water fluoridated at the level recommended by the U.S. Public Health Service (USPHS) reduces dental caries (cavities) by approximately 25% in children and adults (1). USPHS recommends fluoride levels to achieve oral health benefits and minimize risks associated with excess fluoride exposure. To provide the benefits of community water fluoridation, water systems should target a level of 0.7 mg/L and maintain levels ≥0.6 mg/L (2). The Environmental Protection Agency (EPA) sets a safety standard at 2.0 mg/L to prevent mild or moderate dental fluorosis, a condition that causes changes in the appearance of tooth enamel caused by hypermineralization resulting from excess fluoride intake during tooth-forming years (i.e., before age 8 years). During 2016-2021, fluoride measurements for 16.3% of population-weighted monthly fluoride measurements (person-months) reported by community water systems to CDC's Water Fluoridation Reporting System (WFRS) were <0.6 mg/L; only 0.01% of person-months exceeded 2.0 mg/L. More than 80% of population-weighted fluoride measurements from community water systems reporting to WFRS were above 0.6 mg/L. Although 0.7 mg/L is the recommended optimal level, ≥0.6 mg/L is still effective for the prevention of caries. A total of 4,080 community water systems safely fluoridated water 99.99% of the time with levels below the secondary safety standard of 2.0 mg/L. Water systems are encouraged to work with their state programs to report their fluoride data into WFRS and meet USPHS recommendations to provide the full benefit of fluoridation for caries prevention.

A National Study Exploring the Association Between Fluoride Levels and Dental Fluorosis.

Importance: While the effects of fluoride on health have been widely researched, fewer high-quality studies examine the association of fluoride levels in water and dental fluorosis. Objective: To investigate the association between fluoride exposure from drinking water and dental fluorosis. Design, Setting, and Participants: This cross-sectional study used the 2013-2014 and 2015-2016 National Health and Nutrition Examination Survey (NHANES) data (January 1, 2013, through December 31, 2016). NHANES uses a complex sampling technique to develop nationally representative sample estimates of the US population that consists of interviews and physical assessments. Children and adolescents aged 6 to 15 years were included because NHANES contains their data for all 3 forms of fluoride measures: plasma fluoride levels, water levels of fluoride, and dietary fluoride supplementation. Data were analyzed from January 1 to April 30, 2023. Exposures: Water and plasma fluoride levels were measured by laboratory personnel. Dietary fluoride supplement data were self-reported. Main Outcomes and Measures: The Dean's Fluorosis Index was used to evaluate fluorosis status for each tooth. The dental fluorosis severity value was based on the second most affected tooth. Independent variables included plasma and water fluoride concentrations and dietary fluoride supplementation. An independent samples t test was used to compare fluoride exposures between groups, and Pearson correlation assessed the association between plasma and water fluoride levels. To assess whether fluoride exposures were associated with dental fluorosis, logistic regression analyses were conducted. Results: There were 1543 participants in the 2013-2014 NHANES cycle (weighted proportion male, 51.9%; mean [SD] age, 11.0 [2.7] years) and 1452 in the 2015-2016 cycle (weighted proportion male, 52.6%; mean [SD] age, 11.1 [2.8] years). A weighted 87.3% exhibited some degree of fluorosis in the 2013-2014 cycle and 68.2% in the 2015-2016 cycle. Higher fluoride levels in water and plasma were significantly associated with higher odds of dental fluorosis (adjusted odds ratios, 2.378 [95% CI, 2.372-2.383] in the 2013-2014 cycle and 1.568 [95% CI, 1.564-1.571] in the 2015-2016 cycle). Conclusions and Relevance: The findings of this cross-sectional study suggest that exposure to higher concentrations of fluoride in water and having higher plasma levels of fluoride were associated with a greater risk of dental fluorosis. Further research can help policy makers develop policies that balance substantial caries prevention with the risk of dental fluorosis.

Toothbrushing practices as risk factors for dental fluorosis in an area with varying fluoride levels in drinking water.

BACKGROUND: Despite contributing to a reduction in dental caries, improper use of fluoridated toothpaste could add to the burden of dental fluorosis in children. AIM: To assess the association between tooth-brushing practices such as the type and amount of toothpaste used, frequency of tooth brushing, parental assistance in tooth brushing, timing of tooth brushing and dental fluorosis in school children in Kurunegala district, an endemic area for dental fluorosis in Sri Lanka. METHODS: For this case-control study, a sex-matched sample of 15-year-old school children attending government schools in Kurunegala district and who were lifetime residents of the district was selected. Dental fluorosis was measured using the Thylstrup and Ferjeskov (TF) Index. Those children with a TF⟩1 were considered as cases and those with a TF score of 0 or 1 served as controls. An interview of parents/caregivers of the participants was used to assess risk factors for dental fluorosis. The fluoride concentration in drinking water was measured using spectrophotometry. Data analysis used chi-square tests and conditional logistic regression. RESULTS: Tooth brushing ≥ twice/day, brushing after breakfast and parent/care giver brushing the child's teeth reduced the likelihood of developing fluorosis. CONCLUSION: Use of fluoridated toothpaste adhering to the recommended guidelines could prevent dental fluorosis in children in this endemic area.

Fuzzy logic-based health risk assessment of fluoride in groundwater used as drinking source in Sira region, Tumkur, India.

Fluoride contamination in drinking water is a serious public health concern across the world, and more than 90 million people in India are affected by health risks associated with fluoride. Though the fatality due to fluoride chronic toxicity is uncommon, the exposure to fluoride at different concentration levels shows various adverse health effects such as dental and skeletal fluorosis, multiorgan failure, cognitive and behavioural effects. Hence, the objectives of the present study are to understand the hydrogeochemistry and drinking water suitability of groundwater of the Sira region, Karnataka, India, and to understand the occurrence of fluoride and its health risks using the United State Environmental Protection Agency (US EPA) method and fuzzy logic concepts. Forty-six samples were collected from each pre and post-monsoon season. The hydrogeochemistry studied through Chadha's diagram and Gibb's diagram indicated that the groundwater in this region is of Na-Cl type and the hydrogeochemistry is majorly controlled by rock-water interaction and followed by evaporative dominance. Water quality parameters were compared with drinking water standards guidelines, and the results showed that around 50% of the samples were contaminated with fluoride. The occurrence of high levels of fluoride in the study region is associated to the presence of granitic rocks and it is influenced by high pH and low calcium dissolution in the groundwater. Based on US EPA method, the order of population group under the risk of dental and skeletal fluorosis, is children > adolescents > adults. A fuzzy inference system model is developed to assess the health risk due to fluoride and its output gives severity levels of each type of health risk, i.e. dental caries, dental fluorosis and skeletal fluorosis. The results of the application of the fuzzy inference system model in the Sira region showed that the children (< 8 Yr.) are more susceptible to the moderate risk of dental caries, dental fluorosis and skeletal fluorosis. Whereas adolescents (8-18 Yr.) and adults (> 18 Yr.) are less susceptible to low-very low risk. Hence, health risks associated with fluoride can be better addressed with the help of a fuzzy inference system model which can be used for more reliable and grounded results to improve the quality of decision-making.

Association between dental fluorosis prevalence and inflammation levels in school-aged children with low-to-moderate fluoride exposure.

Inflammation mediates the neurological deficits caused by fluoride. Thus, whether inflammation is the underlying mechanism of dental fluorosis (DF) in school-aged children is worth exploring. A cross-sectional study was conducted to investigate the association between inflammation and the prevalence and severity of DF with low-to-moderate fluoride exposure. Fasting morning urine and venous blood samples were collected from 593 children aged 7-14 years. The fluoride content in the water and urine samples was measured using a fluoride ion-selective electrode assay. The levels of interleukin-1ß (IL-1ß) and C-reactive protein (CRP) were detected using an enzyme-linked immunosorbent assay. The Dean's index was used when performing dental examinations. Regression, stratified, and mediation analyses were performed to analyze the association between fluoride exposure, inflammation, and DF prevalence. In the adjusted regression models, the prevalence of mild DF was 1.723-fold (95% confidence interval [CI]:1.612, 1.841) and 1.594-fold (1.479, 1.717) greater than that of normal DF for each 1 mg/L increase in water and urinary fluoride content, respectively. The prevalence of mild DF increased by 3.3% for each 1 pg/mL increase in the IL-1ß level and by 26.0% for each 1 mg/L increase in the CRP level. Stratified analysis indicated a weaker association between fluoride concentration and DF prevalence in boys than in girls, and susceptibility in the boys was reflected by the association of IL-1ß with very mild and moderate DF prevalence. For every 1 mg/L increase in water and urinary fluoride levels, the proportion of IL-1ß-mediated effects on the prevalence of mild DF was 10.0% (6.1%, 15.8%) and 8.7% (4.8%, 15.2%), respectively, and the proportion of CRP-mediated effects was 9.2% (5.5%, 14.9%) and 6.1% (3.3%, 11.0%), respectively. This study indicates that the DF prevalence may be sex-specific. Inflammatory factors may partially mediate the increased prevalence of mild DF in school-aged children with low-to-moderate fluoride exposure.

Necessity to Pay Attention to the Effects of Low Fluoride on Human Health: an Overview of Skeletal and Non-skeletal Damages in Epidemiologic Investigations and Laboratory Studies.

Due to the implementation of water improvement and fluoride reduction plans supported by central and local governments in recent years, areas with high fluoride exposure are being gradually decreased. Therefore, it is of practical importance to study the effect of low fluoride on human health. Epidemiologic investigations and in vivo and in vitro studies based on low fluoride have also confirmed that fluoride not only causes skeletal damage, such as dental fluorosis, but also causes non-skeletal damage involving the cardiovascular system, nervous system, hepatic and renal function, reproductive system, thyroid function, blood glucose homeostasis, and the immune system. This article summarizes the effects of low fluoride on human and animal skeletal and non-skeletal systems. A preliminary exploration of corresponding mechanisms that will help to fully understand the harm of low fluoride on human health was undertaken to provide the basis for establishing new water fluoride standards and help to implement individual guidance.

The association of high-fluoride and high-iodine combined exposure with dental fluorosis and goiter: a meta-analysis.

It is controversial that high-fluoride and high-iodine combined exposure affects the prevalence of dental fluorosis and goiter. The aim of this study was to explore the potential association between high-fluoride and high-iodine combined exposure with dental fluorosis and goiter. We retrieved relevant articles from PubMed, Cochrane Library, China National Knowledge Infrastructure, Wanfang Database and China Science and Technology Journal Database (VIP). The query format was 1 # "Fluorosis" OR "Fluoride," 2 # "Iodine" OR "Iodide," and 3 # 1 AND 2. A total of 20 papers were included in this study after independent review by two investigators. Our analysis showed that high-fluoride and high-iodine biphasic exposure was significantly associated with the prevalence of goiter (OR = 4.69, 95% CI 2.82-7.80, P < 0.001). The prevalence of dental fluorosis was also significantly raised (OR = 11.71, 95% CI 7.57-18.14, P < 0.001). Sensitivity analysis suggested that combined statistics of multiple studies were reliable. For goiter, subgroup analysis revealed study province, sample size and published year as sources of heterogeneity (P < 0.001). For dental fluorosis, only sample size was the impact factor of heterogeneity. As well, funnel plot, Begg's test and Egger's test suggested there was no publication bias (P > 0.05). Overall, our study demonstrates that high-fluoride and high-iodine combined exposure is a risk factor for occurrence of dental fluorosis and goiter. The chronic of high-fluoride and high-iodine combined exposure is a significant higher risk of disease than normal.

A comparative evaluation of the fluoride content in commercially available infant formulae in India: An in vitro study.

CONTEXT: The most critical period for enamel fluorosis to develop is during the early years of life when enamel formation occurs. To minimize the risk of dental fluorosis development, monitoring fluoride intake during teeth development has been suggested. As infant formulae are major source of nutrition in infants, it is important to determine the fluoride content in them in order to monitor the fluoride intake in infants. AIMS: To estimate and comparatively evaluate the fluoride content in different commercially available infant formulae in India. METHODOLOGY: A total of 16 commercially available infant formulae were collected from local pharma/grocery stores, in which 14 were milk based (Group M) and 2 were soy based (Group S). Fluoride content of the formulae was evaluated using ORION F selective electrode. STATISTICAL ANALYSIS USED: ANOVA test, t-test. RESULTS: The mean F values for groups M and S were found to be 0.031 and 0.07 ppm, respectively. Fluoride content of milk-based formulae was significantly lesser (P < 0.001) than soy-based formulae. Daily fluoride intake through the tested formulae was in the range of 0.013 mg and 0.105 mg when calculated following the manufacturer's preparation guidelines. CONCLUSIONS: Infant formulae alone were unlikely to be a risk factor for dental fluorosis, but when reconstituted with optimally fluoridated water, they can be a risk factor for the development of dental fluorosis.

Fluorosis. Antivet contra ácido clorhídrico / fluoride. Antivet vs hydrochloric acid

Introducción: La fluorosis dental es una hipomineralización del esmalte producida como respuesta a la ingesta de fluor por un periodo prolongado durante la formación del esmaltado. Es una alteración irreversible, que clínicamente se caracteriza por la presencia de delgadas líneas blanquecinas distribuidas en el esmalte dental correspondientes a la disposición de las periquimatías, y en grados más avanzados de la enfermedad se odservan cambios en toda la superficie del esmaltado que adquiere un aspecto opaco, como de piedra caliza. En los niveles más severos de flurosis dental, la presencia de hipomineralización, y el aumento en la porosidad del esmalte dental propicia la pérdida de porciones importantes de su estructura, produciendo fracturas, por lo que se deteriora la apariencia y funcionalidad de los dientes afectados. (1) La OMS recomienda que el valor de referencia para el fluoruro en el agua potable es de 1,5 mg /1.(2) El flúor es un gas halógeno, el más electronegativo de los elementos de la tabla periódica, con número atómico 19, prácticamente no existe libre en la naturaleza, sino asociado a otros elementos como: calcio y sodio. La principal vía de incorporación del flúor en el organismo humano es la digestiva. Es absorbido rápidamente en la mucosa del intestino delgado y del estómago, por un simple fenómeno de difusión. Una en los tejidos, depositándose preferentemente en los tejidos duros; se elimina por todas las vías de excreción, principalmente por orina. La cantidad de flúor en el organismo es variable y depende de la ingestión, inhalación, absorción y eliminación, así como de las características de los compuestos. Generalmente se concentra en huesos, cartílagos, dientes y placa bacteriana. El depósito de flúor varía con la edad y la excreción. En los niños, el 50% se fija en huesos y dientes en formación; en adultos, se deposita básicamente en huesos. (3) Existen diversos métodos para su eliminación. En esta investigación se realizaron 18 procedimientos a pacientes de ambos sexos. La metodología fue dividir en dos grupos de 8 personas cada uno, en el cual se utilizó Antivet en el primer grupo y ácido clorhídrico al 18% en el segundo grupo. Los casos fueron seleccionados al azar y posteriormente se observaron los cambios clínicos con cada grupo. En el primer grupo de personas que utilizaron Antivet, se mostró que en casos severos de fluorosis no era un método tan eficaz, ya que no elimina por completo las manchas marrones, sin embargo, es un procedimiento muy bueno para uso clínico cuando los grados de fluorosis son menores. En el segundo grupo de personas que utilizaron ácido clorhídrico al 18% se demostró la eficacia del tratamiento en fluorosis de grados avanzados, donde el esmalte está más del 50% dañado, por lo que es un excelente método de tratamiento con el debido control en su manipulación. Objetivo: Saber diferenciar los tipos de materiales y conocer los diferentes métodos para eliminación de flúor así como mostrar la diferencia entre tratamientos. Metodología: El tipo de estudio es explicativo y con el cual se espera contribuir al desarrollo del conocimiento científico. Su realización supone el ánimo de contribuir al desarrollo del saber científico. Consistió en seleccionar 16 pacientes, masculinos y femenonos y de distintas edades de entre 15 y 40 años. Se dividieron al azar, en 2 grupos de 8 personas cada uno para tratarlos con 2 productos diferentes. El primer grupo fue tratado con ácido clorhídrico al 18% y el segundo grupo con la marca comercial Antivet. Resultado y conclusión: La fluorosis dental es causada por ingestas excesivas de flúor. El uso del ácido clorhídrico es corrosivo, su aroma es penetrante y los cuidados con el paciente son mayores, ya que un mal uso al tener contacto con piel o mucosa creará necrosis. El Antivet tiene desventajas de costo y disponibilidad, pero su ventaja es que brinda más seguridad en su manipulación.

Introduction: Dental fluorosis is a hypomineralization of the enamel produced due to fluoride intake for a prolonged time during enamel formation. It is an irreversible alteration, which is clinically characterized by the presence of thin whitish lines distributed in the dental enamel corresponding to the disposition of the perikymata. In more advanced degrees of the disease, changes are observed in the entire enamel surface, which acquires an opaque appearance, like limestone. In the most severe levels of dental fluorosis, the presence of hypomineralization and increased porosity of the dental enamel leads to the loss of essential portions of its structure, producing fractures, thus deteriorating the appearance and functionality of the affected teeth. (1) The WHO recommends that the reference value for fluoride in drinking water is 1.5 mg/l. (2) Fluoride is a halogen gas, the most electronegative of the periodic table elements, with atomic number 19. It practically does not exist free in nature but is associated with other elements such as calcium and sodium. The primary way of incorporating fluorine into the human organism is through the digestive system. It is rapidly absorbed in the mucosa of the small intestine and stomach by a simple phenomenon of diffusion. Once absorbed, fluoride passes into the blood and is distributed in the tissues, preferentially deposited in hard tissues; it is eliminated by all excretion routes, mainly by the urine. The amount of fluoride in the body is variable and depends on ingestion, inhalation, absorption, elimination, and the characteristics of the compounds. It is generally concentrated in bones, cartilage, teeth, and bacterial plaque. Fluoride deposition varies with age and excretion. In children, 50% is fixed in bones and teeth information; it is basically deposited in bones in adults. (3) There are various methods for its elimination. In this research, 18 procedures were performed on patients of both sexes. The methodology was divided into two groups of 8 persons each, in which Antivet was used in the first group and 18% hydrochloric acid in the second group. The cases were randomly selected, and subsequently, the clinical changes were observed in each group. In the first group of people who used Antivet, it was shown that in severe cases of fluorosis, it was not such an effective method since it does not completely eliminate the brown stains. However, it is a very effective method for clinical use when the degrees of fluorosis are lower. In the second group of people who used 18% hydrochloric acid, the effectiveness of the treatment was demonstrated in advanced degrees of fluorosis, where the enamel is more than 50% damaged, making it an excellent method of treatment with due control in its manipulation. Objective: To differentiate the types of materials and to know the different methods for fluoride elimination as well as to show the difference between treatments. Methodology: The type of study is explanatory, and it is expected to contribute to the development of scientific knowledge. It was carried out to contribute to the development of scientific knowledge. It consisted of selecting 16 patients of both sexes and of different ages between 15 and 40 years old. They were randomly divided into two groups of 8 persons, each to be treated with two different products. The first group was treated with 18% hydrochloric acid, and the second group with the comercial brand Antivet. Result and conclusion: Dental fluorosis is caused by excessive fluoride intake. Hydrochloric acid is corrosive, its aroma is penetrating, and the care with the patient is greater since a wrong use when in contact with skin or mucosa will create necrosis. Antivet has disadvantages of cost and availability, but its advantage is that it provides more safety in its handling.

Effects of chronic fluorosis on the brain.

This article reviews the effects of chronic fluorosis on the brain and possible mechanisms. We used PubMed, Medline and Cochraine databases to collect data on fluorosis, brain injury, and pathogenesis. A large number of in vivo and in vitro studies and epidemiological investigations have found that chronic fluorosis can cause brain damage, resulting in abnormal brain structure and brain function.Chronic fluorosis not only causes a decline in concentration, learning, and memory, but also has mental symptoms such as anxiety, tension, and depression. Several possible mechanisms that have been proposed: the oxidative stress and inflammation theory, neural cell apoptosis theory, neurotransmitter imbalance theory, as well as the doctrine of the interaction of fluorine with other elements. However, the specific mechanism of chronic fluorosis on brain damage is still unclear. Thus, a better understanding of the mechanisms via which chronic fluorosis causes brain damage is of great significance to protect the physical and mental health of people in developing countries, especially those living in the endemic areas of fluorosis. In brief, further investigation concerning the influence of fluoride on the brain should be conducted as the neural damage induced by it may bring about a huge problem in public health, especially considering growing environmental pollution.

Dental Fluorosis and Its Associated Factors Amongst Libyan Schoolchildren.

BACKGROUND: Little is known about dental fluorosis (DF) in Benghazi, Libya, where the public water supply is naturally fluoridated. OBJECTIVE: The study aims to investigate the distribution of DF and its related risk factors and impact on oral health-related quality of life (OHRQoL) and the association between DF and caries amongst Libyan school children. METHODS: A cross-sectional survey was carried out amongst 12-year-old schoolchildren in the city of Benghazi. Dean's and decayed, missing, and filled surfaces (DMF) indices were used to assess the severity of DF and dental caries. In addition, a self-administered questionnaire was used to collect sociodemographic and behavioural information and OHRQoL using the Child Oral Health Impact Profile-Short Version 19 (COHIP-SF19). RESULTS: Out of 1125 children who participated in the study, 15%, 7.8%, 2.2%, and 0.4% of participants were coded as having questionable, mild, moderate, and severe DF, respectively. Children enrolled in private schools were less likely to have DF (odds ratio, 0.55; 95% confidence interval, 0.35-0.83; P = .007). Moderate-severe DF was associated with more decayed surfaces and DMF scores and low scores for COHIP-SF19 and its socioemotional well-being subscale. CONCLUSIONS: The data demonstrate that rates of DF are relatively low in naturally fluoridated areas in Libya. DF amongst Libyan schoolchildren was associated with social disparities, higher caries rates, and negative impacts on OHRQoL.

Potential fluoride exposure from selected food crops grown in high fluoride soils in the Makueni County, south-eastern Kenya.

Makueni County, located in south-eastern Kenya, faces challenges such as limited potable water and restricted food supplies as the result of semi-aridity. High fluoride (F) concentrations have been reported in drinking water with resultant dental fluorosis affecting the local population. To determine the potential F exposure through the consumption of food crops grown in the area, F concentration was assessed in the main five locally grown and consumed crops. Additionally, the water-soluble F fraction was determined from 30 soil samples with mineralogical determination of 20 samples. Mean F concentration in the food crops was in the order; 700, 288, 71.2, 36.6, and 29 mg/kg in kale, cowpeas leaves, green grams, cowpeas (legume portion), and maize, respectively. The F concentration in farm soils ranged from 0 to 3.47 mg/kg (mean of 0.87 mg/kg) and showed a significant strong positive correlation (p = 0.03, r = 0.89) with F values in the crops. Apatite, muscovite, and biotite were identified as the F-rich minerals present. While considering two hypothetical F absorption fractions (75 and 100%), the estimated average daily dose (EADD) of F from consuming the crops ranged between 0.004 and 65.17 mg/kg/day where the highest values were from the vegetables. Most of these values were higher than the F reference dose (RfD) of 0.06 mg/kg. The estimated EADD values of several hypothetical meals prepared from the analyzed crops revealed that steamed kale and maize porridge pose the highest health risk of F associated diseases to the local population, whereas boiled cowpeas pose no health risk. Children, due to their higher daily energy requirement and low body weight, were the most vulnerable group at risk of high daily F intake relative to the RfD. These results suggest that consumption of the analyzed food crops in Makueni County may significantly contribute to F related diseases in the local population. This creates a food security issue for the area because of the potential health risks associated with these crops which are highly relied upon in the semi-arid area with a limited selection of food crops available and viable to grow.

Association of Dietary Calcium Intake with Dental, Skeletal and Non-Skeletal Fluorosis among Women in the Ethiopian Rift Valley.

Fluorosis is a major public health problem in the Rift Valley of Ethiopia. Low calcium (Ca) intake may worsen fluorosis symptoms. We assessed the occurrence of fluorosis symptoms among women living in high-fluoride (F) communities in South Ethiopia and their associations with dietary Ca intake. Women (n = 270) from two villages provided clinical and questionnaire data. Dental fluorosis examination was done using Dean's Index, and skeletal and non-skeletal fluorosis assessment was carried out using physical tests and clinical symptoms. Daily Ca intake was estimated by a food frequency questionnaire. Food, drinking water and beverage samples were analyzed for F level. Many subjects (56.3%) exhibited dental fluorosis. One-third of the women were unable to perform the physical exercises indicative of skeletal fluorosis; about half had ≥2 symptoms of skeletal/non-skeletal fluorosis. The average F level in drinking water sources was ~5 mg/L. The F content in staple food samples varied from 0.8-13.6 mg/kg. Average Ca intake was 406 ± 97 mg/day. Women having ≤400 mg/day Ca intake had ~3 times greater odds of developing skeletal rigidity with joint pains [AOR = 2.8, 95%CI: 1.6, 5.0] and muscular weakness [AOR = 2.9, 95%CI: 1.3, 6.3] compared to those with higher intakes. No association of calcium intake was seen with dental fluorosis. As low dietary Ca intake was associated with symptoms related to skeletal and non-skeletal fluorosis, this warrants nutritional intervention on calcium intakes in this setting.