Search Results (106)

Fluoride remains the keystone of evidence-based caries prevention by stabilizing the mineral balance at the tooth–biofilm–saliva interface. Contemporary understanding emphasizes a predominantly post-eruptive, topical mode of action where fluoride inhibits demineralization and accelerates remineralization. This interfacial catalysis is reinforced by pH-responsive calcium-fluoride-like reservoirs that release fluoride during acid challenges. While community water fluoridation confers population-level reductions, the most effective approach is sustaining low-level fluoride in the biofilm environment. Evidence confirms that toothpastes with 1000–1500 ppm fluoride provide a dose–response benefit in children, while 5000 ppm concentrations are indicated for high-risk scenarios such as root caries and xerostomia. Beyond physicochemical effects, fluoride modulates the oral microbiome by inhibiting bacterial enzymes and proton pumps, shifting community function toward a health-associated state without reducing overall diversity. In restorative dentistry, glass ionomer cements offer superior preventive effects against secondary caries compared to amalgam; however, marginal integrity, adhesive performance, and clinical technique, rather than fluoride release alone, remain the primary determinants of success. Despite well-known risks associated with high systemic intake, such as fluorosis, current evidence does not indicate genotoxic or adverse microbiome effects in humans from routine topical use of standard fluoride products at recommended preventive concentrations. Overall, fluoride’s cariostatic value rests on frequent, low-level exposures that maintain tissues in a repair-favoring state. Full article

Dental fluorosis (DF) remains a global public health challenge traditionally attributed to elevated water fluoride F⁻. However, the Halo Effect and environmental factors now complicate this dose–response relationship. Following PRISMA 2020 guidelines, this systematic review identified 20 observational studies (n = 21,780) via PubMed, Scopus, and Web of Science. Inclusion logic utilized the PICOS framework, specifically selecting human studies that reported quantitative water F⁻ levels alongside environmental or dietary confounders. Quality was assessed via the Newcastle–Ottawa Scale. Synthesis revealed that in optimal fluoridated areas (0.7 mg/L), mild DF prevalence reached 15–20% in cohorts with high “Halo Effect” exposure (infant formula, processed beverages) a twofold increase over historical benchmarks. High altitude (>2000 m) and arid climates further exacerbated toxicity by altering renal clearance. These factors sustain systemic fluoride levels that inhibit protease activity (MMP-20/KLK4) and induce endoplasmic reticulum stress during enamel maturation, causing hypomineralization. Current water-centric monitoring is insufficient for modern risk assessment. A transition toward Total Daily Intake (TDI) models and context-specific standards accounting for altitude and dietary diffusion is essential to balance caries prevention with systemic safety. Full article

Excessive fluoride intake from drinking water remains a public health concern in geogenic high-fluoride regions, yet direct evidence linking environmental fluoride levels to internal exposure in remote high-altitude areas is limited. This study integrated environmental monitoring with human biomonitoring to assess fluoride exposure and health risks in the Taruo Lake region of the Tibetan Plateau. Surface water (n = 45 for Taruo Lake; n = 8 for its tributaries) and groundwater samples (n = 4) were collected and analyzed for fluoride concentrations, and blood ionic fluoride (BIF) levels were measured in 122 local residents (47 adults, 75 children). The results showed that fluoride concentrations in most surface water tributaries of Taruo Lake and groundwater sources were below China’s drinking water standard, whereas those in Taruo Lake exceeded this limit (routine monitoring mean 2.54 mg/L; multi-site mean 2.79 mg/L). BIF levels were significantly higher in adults (0.126 ± 0.041 mg/L) than in children (0.075 ± 0.032 mg/L) and showed a positive correlation with age (r = 0.533, p < 0.001). Notably, 23.4% of adults and 1.3% of children exceeded 0.15 mg/L, an empirical threshold typical for healthy populations in non-endemic areas. Based on the hazard quotient (HQ) model recommended by the US EPA, most drinking water sources posed acceptable non-carcinogenic risks (HQ < 1). In contrast, Taruo Lake water presented an elevated risk (HQ > 1) in 2024 primarily due to the regional geological background, and although not used for daily drinking, this finding offers an indicative reference for local water management and risk prevention. This preliminary monitoring and biomonitoring assessment provides baseline data for future studies and underscores the necessity of continuous surveillance and evaluation of total dietary fluoride intake to protect the health of this vulnerable high-altitude population. Full article

Bottled drinking water is widely consumed in Saudi Arabia; however, the chemical composition of these products and the accuracy of the information presented on their labels remain insufficiently characterized. This study evaluated the composition of 41 still bottled waters purchased from major supermarkets in Riyadh, Saudi Arabia, with emphasis on fluoride, calcium, magnesium, sodium, potassium, hardness, and pH, and examined their potential contributions to dietary mineral intake and caries-preventive fluoride exposure. Products were categorized according to label descriptions, and elemental analyses were performed using a fluoride ion-selective electrode for fluoride and ICP-MS for calcium, magnesium, sodium, and potassium. The pH was measured using a calibrated multiparameter analyzer, and hardness was calculated from calcium and magnesium concentrations. Mineral and purified waters accounted for 75.6% of the sampled products. Fluoride concentrations were generally modest (mean 0.76 ppm; median 0.74 ppm), indicating that the potential contribution of bottled water to caries prevention may vary substantially by brand, and only one product would provide the adult adequate intake for fluoride at a hypothetical intake of 2 L/day. Mean concentrations of calcium, magnesium, sodium, and potassium were 15.10, 7.19, 12.08, and 3.55 mg/L, respectively, indicating limited nutritional significance for most products. Most waters were soft to moderately hard, and pH values were close to neutral. Agreement between label declarations and measured values was inconsistent for fluoride, calcium, and pH. These findings show that bottled waters sold in Riyadh differ considerably in composition and that product labels do not always provide a reliable estimate of fluoride content, mineral content, or pH. From a water quality and public health perspective, bottled water can contribute to daily intake of selected constituents, but in most cases, this contribution is modest and highly brand dependent. Full article

Fluorosis, a systemic condition caused by chronic excessive fluoride intake, poses significant threats to livestock health and agricultural productivity worldwide. This systematic review synthesizes current evidence on the modulatory effects of exercise against fluorosis, integrating human studies, animal experiments, and methodological considerations. Human studies indicate negative associations between fluoride exposure and cognitive development, muscle function, and exercise capacity, with exercise influencing fluoride pharmacokinetics in an exercise-intensity-dependent manner. Animal experiments consistently demonstrate that regular moderate-intensity exercise attenuates fluoride-induced damage across multiple organ systems through activation of the Nrf2/ARE antioxidant pathway, modulation of BMP-2/Smads and OPG/RANKL/RANK signaling, suppression of inflammatory responses, and preservation of intestinal barrier integrity. Substantial heterogeneity exists among current fluorosis models regarding exposure dosages, durations, and exercise protocols, underscoring the need for standardization and consideration of genetic background. Overall, exercise shows promise for mitigating fluorosis-induced multi-organ damage, although human evidence remains limited. Future research should prioritize model optimization, elucidation of molecular targets, and exploration of synergistic interventions to provide a foundation for veterinary clinical management. Full article

The dose–response relationship for fluoride (F⁻) exposure remains largely unexplored. Hence, the current study assessed the hepatotoxic and nephrotoxic effects of subacute exposure (28 days) to increasing F⁻ concentrations in Wistar rats via the benchmark dose (BMD5) method. Thirty male rats were assigned to six groups (n = 5): a control group (tap water) along with five groups that received F⁻ via drinking water at increasing concentrations (10, 25, 50, 100, and 150 mg/L). F⁻ toxicity was determined via water intake, weight gain, histological analyses, redox status, and essential element levels. PROASTweb 70.1 software was utilized to investigate the external and internal F⁻ dose–response relationships. Specified major cytoarchitecture damage and superoxide anion (O₂·⁻), total oxidative status (TOS), superoxide dismutase (SOD) activity, total thiol groups (SH), and advanced oxidation protein product (AOPP) level alterations were detected in both sets of tissues. Moreover, F⁻ caused an imbalance in copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn). The most sensitive parameters were O₂·⁻ (0.06 mg F⁻/kg) in the liver and AOPP (6.5 × 10⁻⁶ mg F⁻/L) in the kidneys. These findings contribute to the limited risk assessment of fluorides and highlight the dose-dependent relationship between redox status parameters and bioelements in the liver and kidneys. Full article

Sustainable groundwater management is essential for water security and human health protection. Fluoride contamination is a serious concern for the sustainable drinking water supply in many parts of Pakistan, including Balochistan, where arid climate conditions and geological formations support the enrichment of fluoride. The toxic nature of fluoride contamination has resulted in negative health impacts on the local population. Conventional geostatistical techniques are usually ineffective to delineate the nonlinear relationships that affect the distribution of fluoride. This study aims to develop a machine learning-driven spatial modelling framework for classifying the spatial distribution of fluoride contamination in groundwater across the study area. The model will help to understand the spatial variability of fluoride contamination and its controlling factors, essential for effective mitigation and early warning systems. Physiochemical elements were used as predictive features in this study, utilizing a unified feature importance framework combining hydrogeochemical analysis, spatial distribution assessment, and ensemble SHAP-based interpretation to identify consistent predictors. Model performance was evaluated using a nested cross-validation framework, followed by validation on an independent geology-informed spatial holdout test set to ensure realistic generalization. Among machine learning models, the Logistic Regression (LR), Support Vector Classifier (SVC), XGBoost (XGB), Decision Tree (DT), Gaussian Naïve Bayes (GNB), and K-Nearest Neighbours (KNN) were evaluated. Support Vector Classifier (SVC) demonstrated a high predictive performance. On the independent spatial holdout dataset, SVC achieved an overall accuracy of 0.75 and an area under the receiver operating characteristic curve (AUC) of 0.821. In addition to classification, a human health risk assessment was conducted using chronic daily intake (CDI) and hazard quotient (HQ) calculations for children and adults, identifying several high-risk water supply schemes. The prediction maps successfully delineated high-risk fluoride points across specific areas, offering a tool for sustainable groundwater management. This study helps to achieve a Sustainable Development Goal (Clean Water and Sanitation, SDG#6) and promotes long-term sustainable planning in water-stressed areas by integrating spatial machine learning mapping and health risk assessment. Full article

Background: This observational ambispective longitudinal international study explored dentists’ practices and patient records concerning dental caries risk management across four European countries (Bulgaria, Greece, Poland and Portugal). Methods: Dentist volunteers recruited patients needing caries risk management, either through preventive or curative measures, from their regular practice. Analyses focused on assessing dentists’ practices in caries risk assessment and management, along with gathering information on patient and dentist characteristics, oral health assessments, and caries risk evaluation. Results: A total of 51 dentists recruited 1008 patients. Across the countries studied, caries risk assessment and management methods varied, with fewer than 15% of dentists using standardized tools. Primary assessment methods included oral examinations and medical interviews, while nutritional and fluoride intake assessments were less common, and salivary or microbiological tests were rare. There was an inverse association between the risk of dental caries and patients’ socioeconomic status. Specific university training on caries risk showed a positive correlation with adherence to recommendations. Conclusions: Our findings emphasize the importance of clinicians adapting their approaches to individual patient needs in caries risk assessment and management. However, the wide array of available risk assessment tools presents a challenge, underscoring the necessity of integrating biopsychosocial models into dental practice to effectively deliver personalized care. Full article

Long-term excessive fluoride intake from food causes skeletal fluorosis, which manifests as bone sclerosis, deformation, joint dysfunction, and even disability. Mitophagy and ion homeostasis regulate bone function. This study investigated the role of melatonin (MLT) in mitigating this condition, given its known involvement in bone remodeling and the fact that fluoride impairs its synthesis in the pineal gland. Firstly, network pharmacology and molecular docking identified mitophagy as MLT’s key pathway against sodium fluoride (NaF)-induced osteosclerosis. Subsequently, a 400 mg/kg/day body weight NaF exposure model in chicken model with 25 mg/kg/day body weight MLT intervention were established in the current study. Fluoride exposure caused the disturbance of ion homeostasis, and the impairment of mitochondria and activation of PTEN-induced putative kinase1 (PINK1)/E3 ubiquitin ligase Park2 (Parkin)-mediated mitophagy in the bone. Importantly, these deleterious effects were significantly restored by MLT supplementation. In conclusion, NaF causes bone injury via ion homeostasis disruption, osteoblast mitochondrial damage, leading to excessive mitophagy. MLT inhibits fluoride-induced mitophagy through the calcium ion flow-mediated PINK1/Parkin pathway, mitigating bone damage. This study can not only ensure the safety of animal-derived food but also provide a theoretical basis for the prevention and treatment of fluorosis in humans and animals. Full article

Background/Objectives: The aim of this study was to evaluate the oral health status of socially vulnerable children and adolescents in Seville and to examine its associations with behavioral and sociodemographic determinants. We hypothesized that greater social vulnerability and suboptimal behaviors would be associated with higher caries experience. Methods: A cross-sectional analytical study was conducted on 250 participants aged 2 to 17 years attending the Luis Séiquer Social Dentistry Foundation between January and March 2025. Clinical examinations followed the WHO Oral Health Surveys: Basic Methods (5th edition, 2013) and were performed by a calibrated dentist. Variables included dental caries indices (dft, DMFT), pulpal treatment needs, and oral hygiene practices. Statistical analyses included Kruskal–Wallis, Mann–Whitney U, Fisher’s exact tests, and multivariate regression models (significance level p < 0.05). Results: Caries prevalence was high across all age groups, particularly in primary dentition (mean dft = 3.05 ± 3.80; DMFT = 2.99 ± 3.66; p < 0.001). Pulp therapy needs were significantly higher among preschoolers (mean = 2.22 ± 2.31). Factors such as low parental education, migrant background, insufficient toothbrushing frequency, and frequent sugar intake were strongly associated with poorer oral health outcomes. Although fluoridated toothpaste use was widespread (>94%), dental floss use remained limited (34.8%). Multivariate analyses confirmed a strong association between social inequalities and oral disease burden. Conclusions: Children and adolescents from vulnerable groups in Seville experience a high prevalence of dental caries and substantial unmet treatment needs. Findings highlight marked oral health disparities linked to socioeconomic status, emphasizing the urgent need for early preventive programs, culturally adapted oral health education, and equitable access to dental care. Full article

Dental caries remains one of the most prevalent chronic diseases worldwide, driven by complex interactions among dietary, hygienic, and biological factors. This study introduces a hybrid predictive framework that integrates mathematical modelling and artificial intelligence (AI) to estimate individual caries risk based on daily sugar intake, oral hygiene index, salivary pH, fluoride exposure, age, and sex. A first-order balance differential equation was applied to simulate demineralisation–remineralisation dynamics, while a feed-forward artificial neural network (ANN) was trained on simulated and literature-derived datasets. The hybrid model demonstrated strong predictive performance, achieving 91.2% accuracy and an AUC of 0.98 in classifying individuals into low-, moderate-, and high-risk categories. Sensitivity analysis identified sugar intake and oral hygiene as dominant determinants, while fluoride and salivary pH showed protective effects. These findings highlight the feasibility of combining mechanistic and data-driven approaches to enhance early risk assessment and support the development of intelligent, personalised screening tools in preventive dentistry. Full article

Breastfeeding based on the use of follow-on milk may contain traces of xenobiotic elements that could pose a risk to the health of the vulnerable population for which it is intended. Fluorine is a non-essential element that, at high concentrations, can produce adverse health effects such as dental fluorosis, decreased IQ (intelligence quotient), thyroid alterations, and kidney damage. Given the vulnerability of infants and the possible presence of fluoride in this type of product, the content of this anion was determined in a total of 46 samples of follow-on milk from different brands and types (starter, follow-on, and hydrolysate formulas) using a fluoride ion-selective electrode (EWI). The highest mean concentration of fluoride was recorded in the hydrolysate formulas (3.38 ± 2.78 mg/L). The dietary intake assessment indicated that some brands of hydrolyzed formulas could pose a health risk, providing up to 94.1% of the UL (upper level) with only one 90 mL serving in the 0–6-month age group. It is recommended that consumers be aware of the fluoride content in the water used to prepare bottles, as it can further increase total fluoride intake and therefore pose a risk to the health of infants. Full article

Fluoride is a widespread environmental toxin that disrupts metabolic and endocrine functions, but its impact on pancreatic inflammation and hormone secretion remains unclear. This study examined how chronic fluoride exposure affects pancreatic inflammation and secretory function in rats. Pregnant Wistar rats received sodium fluoride (NaF) at 50 mg/L in drinking water during gestation and lactation. Male offspring continued exposure until 3 months old. Controls received fluoride-free water. Pancreatic tissue and serum were collected. Fluoride levels were measured potentiometrically. Eicosanoids were quantified by SPE and HPLC. Serum insulin, glucagon, and somatostatin were measured by ELISA. Histological and biochemical markers of inflammation and oxidative stress were assessed. Fluoride exposure did not lead to significant accumulation in the pancreas or serum. However, fluoride-exposed rats exhibited a significant decrease in serum insulin and somatostatin concentrations, while glucagon levels remained unchanged. Additionally, the pancreas of fluoride-treated animals showed markedly elevated levels of pro-inflammatory eicosanoids, including prostaglandin E2, leukotrienes A4 and B4, and HETE/HODE derivatives, indicating activation of cyclooxygenase and lipoxygenase pathways. Sustained low-dose fluoride exposure induced pancreatic inflammation and disrupted endocrine homeostasis in rats. These findings suggest that chronic fluoride intake may impair insulin secretion and promote pre-diabetic alterations, warranting further research. Full article

Background/Objectives: Fluorides play a well-established role in preventing dental caries, primarily by enhancing enamel resistance and inhibiting demineralization. Drinking water is among the most important sources of systemic fluoride intake. In 1993 and 2007, national analyses of Austrian drinking water revealed fluoride levels below 0.5 mg/L in almost all regions, which is insufficient for effective caries prevention. The present study aimed to re-examine the fluoride concentration in Austrian drinking water. Methods: Drinking water was collected in a total of 1985 Austrian municipalities. Fluoride concentration was measured by a fluoride-selective electrode. Results: The average fluoride concentration in the measured water samples ranged between 0.1 and 0.27 mg/L, depending on the region. The analysis revealed that 98% of the municipal drinking water samples contained fluoride at concentrations below 0.5 mg/L. In almost one quarter of Austrian municipalities, the fluoride levels amounted to less than 0.1 mg/L. The fluoride concentration in the drinking water of one Tyrolean municipality exceeded the recommended threshold. Conclusions: The results of the study reveal that the fluoride concentration in Austrian drinking water is generally too low to provide effective prevention against dental caries, affecting nearly all municipalities. Notably, the drinking water of one municipality reached potentially harmful fluoride levels. These findings could be used as a basis for targeted and individual fluoride supplementation, as well as for national or area-specific guidelines. Full article