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An animal model was applied to develop erosive tooth wear (ETW) and to evaluate the efficacy and safety of titanium tetrafluoride (TiF4) in preventing ETW. Forty-eight male Wistar rats were divided into three groups (n = 16): TiF4 (2.45% F−), NaF (2.45% F−) and placebo varnishes. Eight from each group were subjected to erosive challenges (Sprite Zero) and the other received tap water, both ad libitum. After twenty-eight days, the mandibles were resected for histopathological gingival analysis, clinical and microscopic tooth evaluation by 3D confocal laser microscopy, scanning electron microscopy (SEM-EDX) and micro-Raman spectroscopy (MRS). Organs were evaluated with respect to fluoride content. No significant difference was found in F content in tissues. No histopathological damage was seen in gingiva. ETW was clinically more aggressive in rats from placebo group consuming Sprite compared to water (Q²=12.6, p < 0.01), in accordance with confocal images. TiF4 was superior in reducing cross-section area loss (0.036 ± 0.01µm2) compared to NaF and placebo, respectively (0.044 ± 0.01/0.063 ± 0.01µm2, ANOVA, p < 0.0001). Dentin exposure was detected by SEM in rats belonging to placebo consuming Sprite. Peaks compatible with typical apatite bands were visible. TiF4 reduces the progression of ETW without causing any relevant side-effect and the rats' model was able to simulate ETW in vivo. [ABSTRACT FROM AUTHOR]

A simple two step synthetic method for di‐doped crystalline mesoporous tin dioxide powder containing antimony and fluoride at ambient pressure and temperature has been developed. This approach produced materials with high surface areas and improved electrical and optoelectrical conductance. The two dopant elements; antimony and fluoride were introduced to tin dioxide by two approaches. Both approaches produced mesoporous tin dioxide with antimony and fluoride that are integrated in the framework. The structures of these materials are analyzed by powder X‐ray diffraction, N2 sorption analysis, transmission electron microscopy, energy dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy. The conductance of the materials improved by factor of 13–34 compared to undoped mesoporous tin dioxide. The effect of the di‐doped elements on structure, conductance and optoelectronic properties of these materials are discussed in this paper. [ABSTRACT FROM AUTHOR]

Objective: Patients receiving head and neck radiation are at high risk for radiation caries. This study aimed to evaluate the remineralizing effects of an experimental 1.1% NaF (5000 ppmF) toothpaste containing Sr/F-doped bioactive glass nanoparticles (BAG or B) on demineralized irradiated dentin. Materials and methods: Fluoride concentration and pH stability of materials upon mixing with water were assessed using a fluoride-specific electrode (n = 3) for up to 3 months. Elemental release of materials in water was determined using ICP-OES (n = 3). Fourteen extracted molars were irradiated with a cumulative dose of 70 Gy. Each tooth was sectioned into 4 specimens (n = 14/group), demineralized, and subjected to pH cycling for 14 days. Groups were treated with Prevident (PV), E5000, E5000B, and deionized water twice daily. Remineralization was assessed using ATR-FTIR (mineral-to-collagen ratio) (n = 14). Mineral precipitation was additionally examined with SEM-EDX. The in vitro cytotoxicity of the materials on L929 mouse fibrosarcoma was evaluated with the MTT test (n = 3). Kruskal-Wallis test, followed by Dunn's procedure, was used to compare the data between groups. Result: PV demonstrated greater pH and fluoride release stability than the experimental materials. E5000B exhibited a slight reduction of fluoride release (p < 0.01, R²=0.656) and an increase in pH with time (p = 0.006, R²=0.233). The highest increase in mineral-to-collagen ratio at 14 days was detected with PV (p < 0.05). E5000B also showed a significantly higher ratio than E5000 (p = 0.014). SEM-EDX detected mineral precipitation on dentin treated with PV and E5000B but not in E5000 and DI. The cell viability of PV (56%) was significantly lower than that of E5000 (94%) and E5000B (89%) (p < 0.05). Conclusion: The use of 5000 ppm fluoride toothpaste enhanced the remineralization of irradiated demineralized dentin, highlighting a potentially valuable strategy for preventing radiation caries. Adding bioactive glass further promoted remineralization but may require formulation adjustments to maintain toothpaste stability for clinical use. [ABSTRACT FROM AUTHOR]

This study investigated the combined effects of adding niobium–fluoride (NbF5) nanoparticles to a pit-and-fissure sealant. One resin sealant was reinforced with varying amounts of nanoparticles (0.3, 0.6, and 0.9 wt%). The surface hardness (SH), energy-dispersive X-ray spectroscopy (EDX), surface roughness (Ra), color change (ΔE), and mineral deposition were assessed. Bovine enamel blocks were subjected to demineralization and pH-cycling for SH. The elemental composition and Ca/P ratio were evaluated using EDX, while the mineral deposition was measured using Fourier transform infrared spectroscopy (FTIR). Data were analyzed using ANOVA and Tukey's test for the SH and EDX, ΔE, and Kruskal–Wallis for the Ra. The NbF5 modification increased the SH, with the 0.9 wt% sealant exhibiting higher SH values, and the 0.3 wt% one exhibiting significant differences compared to the control and the 0.9 wt% (p = 0.00) samples, even after pH-cycling. For the EDX analysis, the 0.3 and 0.6 wt% samples exhibited higher Ca/P ratios, with the 0.3% one showing evidence of P-O crystal formation. There was no significant difference in the Ra (p = 0.458), and the 0.6 and 0.9 wt% ones showed lower ΔE values compared to the control. The 0.3 wt% NbF5 demonstrated improved overall properties, making these results particularly promising for preventing tooth decay, reducing demineralization through increased ions release and promoting remineralization in posterior teeth. [ABSTRACT FROM AUTHOR]

The prevalence of osteoarthritis (OA) in Tibetans is higher than that in Han, while Tibetans have a habit of drinking brick tea with high fluoride. A cross-sectional study was conducted to explore the association between fluoride exposure in drinking brick tea and OA. All subjects were divided into four groups by the quartiles (Q) of tea fluoride (TF) and urine fluoride (UF). ROC was plotted and OR were obtained using logistic regression model. The prevalence of OA in the Q3 and Q4 group of TF were 2.2 and 2.7 times higher than in the Q1 group, and the prevalence of OA in the Q2, Q3 and Q4 group of UF were 3.2, 3.5, and 4.1 times higher than in the Q1 group. ROC analysis showed the cutoff values were 4.523 mg/day (TF) and 1.666 mg/L (UF). In conclusion, excessive fluoride in drinking brick tea could be a risk factor for developing OA. [ABSTRACT FROM AUTHOR]

[Display omitted] • SIRT1 activation exerted protective roles against fluoride-induced cognitive defects. • SIRT1 activation restored fluoride-caused defective mitochondrial network dynamics. • SIRT1 was targeted directly by miR-708-3p. • MiR-708-3p mediated the neurotoxic process of fluoride via directly targeting SIRT1. • SIRT1, a target of miR-708-3p , alleviates fluoride-induced neuronal damage via remodeling mitochondrial network dynamics. Neurological dysfunction induced by fluoride contamination is still one of major concern worldwide. Recently, neuroprotective roles of silent information regulator 1 (SIRT1) focusing on mitochondrial function have been highlighted. However, what roles SIRT1 exerts and the underlying regulative mechanisms, remain largely uncharacterized in such neurotoxic process of fluoride. We aimed at evaluating the regulatory roles of SIRT1 in human neuroblastoma SH-SY5Y cells and Sprague-Dawley rats with fluoride treatment, and to further identify potential miRNA directly targeting SIRT1. Pharmacological suppression of SIRT1 by nicotinamide (NIC) and promotion of SIRT1 by adenovirus (Ad-SIRT1) or resveratrol (RSV) were employed to assess the effects of SIRT1 in mitochondrial dysfunction induced by fluoride. Also, miRNAs profiling and bioinformatic prediction were used to screen the miRNAs which can regulate SIRT1 directly. Further, chemical mimic or inhibitor of chosen miRNA was applied to validate the modulation of chosen miRNA. NIC exacerbated defects in mitochondrial network dynamics and cytochrome c (Cyto C) release-driven apoptosis, contributing to fluoride-induced neuronal death. In contrast, the ameliorative effects were observed when overexpressing SIRT1 by Ad-SIRT1 in vitro or RSV in vivo. More importantly, miR-708-3p targeting SIRT1 directly was identified. And interestingly, moreover, treatment with chemically modified miR-708-3p mimic aggravated, while miR-708-3p inhibitor suppressed fluoride-caused neuronal death. Further confirmedly, overexpressing SIRT1 effectively neutralized miR-708-3p mimic-worsened fluoride neuronal death via correcting mitochondrial network dynamics. On contrary, inhibiting SIRT1 counteracted the promotive effects of miR-708-3p inhibitor against neurotoxic response by fluoride through aggravating abnormal mitochondrial network dynamics. These data underscore the functional importance of SIRT1 to mitochondrial network dynamics in neurotoxic process of fluoride and further screen a novel unreported neuronal function of miR-708-3p as an upstream regulator of targeting SIRT1, which has important theoretical implications for a potential therapeutic and preventative target for treatment of neurotoxic progression by fluoride. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the preventive and discoloring effects of a single and two weekly applications of 38% silver diamine fluoride (SDF) against dentin erosion. Materials and methods: 180 dentin blocks were divided into four groups. Group 1 (SDF2) received two weekly applications of 38% SDF. Group 2 (SDF1) received a single application of 38% SDF. Group 3 (SNF) received a daily application of stannous chloride/amine fluoride/sodium fluoride (standard of care for dental erosion). Group 4 (DW) received a daily application of deionized water. The treated blocks were subjected to a 14-day erosive challenge. Crystal characteristics, elemental composition, surface morphology, percentage of surface microhardness loss (%SMHL), surface loss, and color change (ΔE) were investigated using X-ray diffraction (XRD), energy-dispersive spectrometry (EDS), scanning electron microscopy (SEM), hardness testing, profilometry, and digital spectrophotometry, respectively. Results: XRD and EDS showed dentin surfaces had silver compounds in SDF2 and SDF1, and stannous chloride in SNF. SEM revealed less dentin demineralization with tubular occlusion in SDF2, SDF1, and SNF, but severe demineralization in DW. The %SMHL of SDF2, SDF1, SNF, and DW were 10.8 ± 2.1, 15.7 ± 2.1, 17.9 ± 2.1, and 28.7 ± 2.0 (SDF2 < SDF1 < SNF < DW, p < 0.05). Surface loss (µm) of SDF2, SDF1, SNF, and DW were 5.0 ± 0.6, 6.0 ± 0.6, 6.0 ± 0.7, and 9.0 ± 0.5 (SDF2 < SDF1 = SNF < DW, p < 0.001). ΔE of SDF2, SDF1, SNF, and DW were 26.0 ± 3.4, 12.1 ± 3.8, 6.9 ± 3.5, and 3.9 ± 3.6 (SDF2 > SDF1 > SNF = DW, p < 0.001). Conclusion: 38% SDF with two weekly applications provided better preventive effects against dentin erosion, but it might discolor dentin. Clinical relevance: The increased 38% SDF application showed a better anti-erosive potential against dentin erosion. However, SDF caused black staining on the dentin. [ABSTRACT FROM AUTHOR]

Fluorosis decreases the learning and memory ability in humans and animals, while exercise can reduce the risk of cognitive decline. However, the effect of exercise on learning and memory in fluoride-exposed mice is unclear. For this purpose, in this study, mice were randomly allotted into four groups (16 mice per group, half male and half female): control group (group C), fluoride group (group F, 100 mg/L sodium fluoride (NaF)), exercise group (group E, treadmill exercise), and E plus F group (group EF, treadmill exercise, and 100 mg/L NaF). During 6 months of exposure, exercise alleviated the NaF-induced decline in memory and learning. In addition, NaF induced injuries in mitochondria and myelin sheath ultrastructure and reduced the neurons number, while exercise restored them. Metabolomics results showed that phosphatidylethanolamine, pregnenolone (PREG), and lysophosphatidic acid (LysoPA) were altered among groups C, F, and EF. Combined with previous studies, it can be suggested that PREG might be a biomarker in response to exercise-relieving fluorine neurotoxicity. The miRNA sequencing results indicated that in the differently expressed miRNAs (DEmiRNAs), miR-206-3p, miR-96-5p, and miR-144-3p were shared in groups C, F, and EF. After the QRT-PCR validation and in vitro experiments, it was proved that miR-206-3p could reduce cell death and regulate AP-1 transcription factor subunit (JunD) and histone deacetylase 4 (HDAC4) to alleviate fluoride neurotoxicity. To sum up, the current study reveals that exercise could alleviate NaF-induced neurotoxicity by targeting miR-206-3p or PREG, which will contribute to revealing the pathogenesis and therapeutic method of fluoride neurotoxicity. [ABSTRACT FROM AUTHOR]

The randomized study aimed to evaluate the comparability of in situ (iS) and in vitro (iV) study protocols regarding remineralization of artificial enamel lesions. Two toothpastes (group A: 1450 ppm sodium fluoride, group B: placebo 0 ppm F-), were investigated. IV, a pH-cycling model with toothpaste slurry treatment was applied for 10d. IS, remineralization was performed in 9 participants wearing splints with embedded enamel samples for 10 and 21d, randomly allocated to groups A and B. Samples were scanned by X-ray micro-computed tomography (μCT) and grayscale value line profiles corresponding to mineral density (rel.ΔZ) were analyzed. Statistical analyses were performed using MedCalc Statistical Software, v22.021. T-Test for dependent and independent data and analysis of variance (ANOVA) were used for further analyses (α = 0.05). Rel.ΔZ of fluoride treated samples (A) were iV = 40.2%, iS 10d = 11.5% and iS 21d = 46.1% (p > 0.05). Rel.ΔZ of placebo treated samples (B) were: iV = − 6.2%, iS 10d = 25.2% and iS 21d = 11.0% (p > 0.05). Remineralization potential of both toothpastes was significantly different regarding iV (p < 0.001) and iS after 21d (p = 0.034), while in case of iS 10d no significant difference was detected (p = 0.4). Despite different study protocols the μCT results after remineralization were comparable between iV and iS. The results suggest that selected studies can be carried out in faster, simplified iV studies using pH-cycling instead of iS studies. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to examine the complex relationships between environmental monitoring efforts (EME), community engagement (CE), and environmental risk perception (ERP) in the context of improving environmental disaster preparedness (EDP) in the specific case of fluoride pollution. Using the Theory of Planned Behavior (TPB) as a conceptual framework, the study examines the effect of several variables on disaster preparation behavior in communities exposed to environmental risks. Methods: The data was collected from people living in Shanxi Province, China, an area that suffers from severe fluoride contamination. Results: The results of structural equation modeling (SEM) indicate that community engagement significantly improves the perception of environmental risk, which, in turn, positively impacts the preparation for disasters. Moreover, environmental monitoring efforts were shown to be a mediator of the association between community participation and disaster preparation, underscoring the crucial role that systematic monitoring plays in disaster management. The results indicate that including social and environmental elements is crucial for improving the ability of communities to withstand and recover from environmental catastrophes. Conclusion: The findings emphasize that there is an urgent need to consider social, and environmental aspects if the resilience of communities to, and their recovery from, environmental disasters is to be improved. [ABSTRACT FROM AUTHOR]

The Defluoridation Technology Project was called upon to survey existing water resources by three different institutions lying in fluorotic Tanzania: 1) The Ngongongare Secondary School. 2) The St Constantine International School and 3) The Minjingu Church Project. In case 1), due to low affordability, an open dug well was proposed. In case 2) a defluoridation system was installed and could be used to estimate essential design parameters, as Operation Period (1 Year), Removal Efficiency (93 %) and Removal Capacity (3-4 mg/g of Bone Char). In case 3) the water was deadly toxic because of high fluoride concentrations, but, fortunately, unpalatable due to high contents of Alkalinity/Salinity. The salinity renders the defluoridation process useless. A system of combined rain water harvesting and defluoridation of brought water sources was proposed. [ABSTRACT FROM AUTHOR]

Purpose: This study was designed to study testicular-histopathology and lipid profile against 50ppm of fluoride (ad labitum) exposure in mice. Moreover, the curative potentials of vitamin E, Punica granatum and Olea europea fruit extracts were also studied. Methods: Five groups (10 animals/group) were treated as follow (a) Control (C) (F free water-15 days); (b) NaF {50ppm F-ions in drinking water (10days) and F free water (5days)}; (c) NaF + vitamin E (NaFE) {50ppm F-ions (10days) and F free water+60µg vitamin E in corn oil (5days)}; (d) NaF+ Punica granatum fruit extract (NaFP) {50ppm F ions (10days) and F free water+0.2mL P. granatum fruit extract (5days)}; (v) NaF+ Olea europea fruit extract (NaFO) {50ppm F-ions (10days) and F free water +0.2mL O. europea extract (5days)}; All animals were sacrificed on day 16 to obtain blood for lipid profile and testes for histopathological studies. Results: Results shows peculiar histopathological changes in the testis, including the loss of interstitial tissues, spermatogonia, spermatocytes, spermatids and maturing sperms. These signs were convincingly recovered in NaFO, followed by other two post treatment groups NaFP and NaFE. Similarly the micrometric data shows significant increase in the number of spermatogonia, spermatocytes and developing spermatozoa, in NaFO (CSA of seminiferous tubules, number of spermatogonia, spermatocytes:, sperms embedded in sertoli cells & number of dislodged sperms). The rise of High Density Lipoproteins (HDL) with a simultaneous decline in plasma cholesterol, Low Density Lipoprotein (LDL) and Very Low Density Lipoprotein (VLDL) in NaFO indicate the importance of these post treatments, against altered lipid profile of the F toxicology. Excellent testicular rehabilitation found in NaFO group that indicate the curative potential of O.europea against altered histopatology against F exposure in testes. Conclusions: The severity of the mentioned pathology of NaF group indicates that Olea europea and Punica granatum post treatment can effectively eradicate the toxic changes of F exposure in lipid profile, while Olea europea fruit extract showed more ameliorationative capability against F-exposure in testes. [ABSTRACT FROM AUTHOR]

Purpose: This paper's aim is to highlight the essential factors influencing the fluoride management programs' effectiveness and dentistry overall. This multisided, complex, and multifaceted issue requires a thorough understanding of several social, political, and cultural factors that can be altered or utilized to enhance fluoride management, a factor that would reduce caries significantly and raise the patient's overall level of dental health. Methods: The paper takes data conducting on health officials, in addition to administration staff at high-fluoride regions in China and Pakistan. Results: The results obtained clearly indicate that the relationship between social media representation, stakeholder pressure, public engagement, political support factor and the effectiveness of the fluoride management program is mediated through prior public knowledge and awareness levels. Additionally, the moderation and factors' moderating effects show that political support modulates the relationship between stakeholder pressure, public engagement, and public awareness. Conclusion: In conclusion, the results bring additional evidence as to the factors based on public awareness raising, support from politicians to the stakeholders and patient's pressure-inducing to a more successful and, therefore, the more effective result. For policymakers, public health practitioners, and community leaders, the finding calls for more evidence as to what can be done to achieve the optimal results of the fluoride-managing program. Future research should focus on similar issues as fluoride managing to see similar results. [ABSTRACT FROM AUTHOR]

Copper is an active electrocatalyst for various energy conversion reactions, but its performance depends on the structure of the active surface sites. In this work, we propose a simple strategy to tailor both the roughness and the active site's geometry of copper. To modify the surface of copper, we oxidize and reduce a copper polycrystalline electrode in 0.1 M solutions containing both sodium fluoride and sodium chloride with different chloride/fluoride molar ratios: (0.1‐x) M NaF+x M NaCl. To address the anion effect on the changes in surface geometry, we recorded the voltammetric fingerprints of the modified electrodes using lead underpotential deposition (UPD). The voltammetric analysis suggested that while chloride induces (n10) sites, fluoride promotes an increase in the active surface area and the growth of low‐coordinated sites with (110) or (111) geometry. Solutions containing both fluoride and chloride anions induced (n10) motifs covered by nanometric clusters, as observed by scanning electron microscopy, forming a highly defect‐rich surface. Our work provides a direct link between electrochemical response and ex‐situ structural characterization, and compares, in detail, the effect of chloride and fluoride on the surface nanostructuring of copper. [ABSTRACT FROM AUTHOR]

This study focused on fluoride (F−) contamination of water sources in Bahimi village, Cameroon. After the first investigation, results revealed that all water samples collected had elevated concentrations of fluoride ions (2.3 ± 0.1) mg/L to (4.5 ± 0.2) mg/L above the WHO guidelines (less than 1.5 mg/L). To mitigate the F− levels, the use of bone char (BC) as an adsorbent material was proposed and its performance was tested. BC was prepared from bovine bones at different calcination temperatures (350 °C, 450 °C, 550 °C and 650 °C) and residence times (1 h and 2 h). The prepared materials were characterized in detail by SEM/EDS, BET, FTIR, and XRD. The BET findings indicated that the surface area of BC samples decreased with increasing calcination temperature and residence time. At a lower heating temperature and holding time (350 °C, 1 h), the prepared BC exhibited a higher specific surface area (112.3 ± 0.3) m2/g and adsorption capacity for F− in the sampled water. Also, the batch adsorption experiments showed that the optimized adsorbent dose of 8 g/L facilitates the reduction in the F− level of the sampled water below the acceptable limit level (1.5 mg/L) within 5 min of treatment. The presence of Ca2+ and Mg2+ in natural water has a positive effect on the removal of F− in BC resulting in a high adsorption performance range of (72.5 ± 1.4)% to (80.3 ± 0.6)%. It was found that the adsorption of Ca2+ on the BC surface occurs via cation exchange with Na+. However, an increase in dissolved organic carbon (DOC) in the treated water limited the application of BC. Overall, the study presented a cost-effective adsorbent for the removal of this recalcitrant ion in the water source. [ABSTRACT FROM AUTHOR]

Background: The Internet and social media have become many people's primary sources of health information. Instagram is one of the most popular social media platforms, and users spend a significant amount of time daily on the platform. Therefore, analyzing oral health-related information shared online can help to identify the requirements of specific groups, assisting in the planning and execution of educational public health actions. As a result, this study was carried out to conduct a qualitative evaluation of fluoride-related content on Instagram in 2022–2023. Methods: Using hashtags associated with fluoride, a search was conducted on the Instagram application in the Persian language. All fluoride-containing posts were saved, and data was collected thrice at two-month intervals. MAXQDA software version 2020 was used to categorize the collected data content based on type, quality, and quantity. Results: The qualitative analysis included 1565 (9.45%) posts with fluoride-related content out of 16,475 total posts. After removing the duplicates, 400 posts remained, among which 282 posts (70.5%) and 118 posts (29.5%) were pro- and anti-fluoride, respectively. After qualitative analysis, 270 codes were examined and categorized into three main themes and eight subthemes: "fluoride sources," "The advantages and disadvantages of fluoride," and "Invalid beliefs about fluoride." Conclusion: The frequency of pro-fluoride use was higher than anti-fluoride posts. However, due to the high prevalence of posts containing false information on fluoride toxicity for health, ineffectiveness on caries prevention, and conspiracy theories, there is a need to improve the quality of information on fluoride by providing scientific and unbiased explanations by professionals online or during dental visits and supervising social media content. [ABSTRACT FROM AUTHOR]

Background: The safety of oral hygiene products is a growing concern, particularly regarding the toxicity of specific ingredients used in their formulations. The purpose of this study was to evaluate the knowledge and attitudes of dentists, physicians, pharmacists, and the general public regarding ingredients in oral hygiene products, especially fluoride. Additionally, this study aimed to identify which ingredients may exhibit potential toxicity based on historical records of any adverse effects being induced by a material/component. Methods: A self-administered questionnaire was used in an online cross-sectional observational study to collect data on sociodemographic characteristics, knowledge of fluoride in dental medicine, fluoride usage practices in oral hygiene products, opinions on ingredient toxicity in oral hygiene products, and personal experiences of adverse reactions to products and their components. The collected data underwent descriptive and regression analyses to reveal patterns and relationships within the dataset. Results: The study found a moderate overall knowledge level regarding fluoride usage in dentistry among participants (Md = 5.00, IQR 2.50–7.00). Healthcare professionals exhibited significantly higher knowledge scores compared to the general population (p ≤ 0.001), with dental professionals displaying the highest scores. Regarding concerns about the usage of fluoride, the majority of respondents (77.0%) did not express any concerns. Minor concerns included the risk of ingestion (6.0%) and dental fluorosis (4.6%). Among the other ingredients in oral hygiene products, respondents named alcohol as the most toxic ingredient (70.3%), followed by artificial colors (53.1%), artificial sweeteners (50.4%), and parabens (50.1%). It is noteworthy that the majority of participants (61.6%) stated that they had never experienced any side effects associated with the use of oral hygiene products. Conclusion: This study underscores disparities in fluoride knowledge between healthcare professionals and the general population in Croatia, with dental experts exhibiting a superior understanding. Despite lingering misconceptions about fluoride content and potential toxicity, the majority of participants acknowledge its oral health benefits and use fluoride products regularly. [ABSTRACT FROM AUTHOR]

Objective To analyze the types, origins, fluoride content of brick tea available in the Sanjiangyuan region, and the local residents' consumption of milk tea, providing a scientific basis for assessing the safety of fluoride intake from brick tea. Methods In 2022, based on historical data, a survey was conducted in 11 counties (cities) in the Sanjiangyuan region where residents habitually consume milk tea. Villages with a brick tea consumption habit were selected as the unit of investigation within each county. Ten households were randomly sampled from each village to collect demographic data and information on milk tea consumption. Samples of drinking water, brick tea, and milk tea were collected to measure fluoride content, calculating the daily per capita fluoride intake from milk tea for individuals over 16 years of age. The fluoride content in water and tea was measured using ion-selective electrode methods. Results A total of 82 drinking water samples were collected, with an average fluoride concentration of 0.22 mg/L, ranging from 0.10 to 0.74 mg/L. A total of 873 brick tea samples were collected, primarily consisting of Kang brick and Fu brick, accounting for 42.96% (375/873) and 34.48% (301/873) of the total, respectively. Other varieties included Jin Jian (11.80%, 103/873), Da tea (4.81%, 42/873), Hei brick (4.35%, 38/873), and Qing brick (1.60%, 14/873). There were 69 brands of brick tea available, predominantly produced in Sichuan Province (56.24%, 491/873), followed by Hunan Province (37.46%, 327/873). The average fluoride content in brick tea was 752.3 mg/kg, with a range of 242 to 1 836 mg/kg, with Jin Jian and Kang brick showing significantly higher fluoride levels (P < 0.001). Only three samples of brick tea had fluoride content ≤300 mg/kg, representing 0.34% of all samples. The annual per capita consumption of brick tea for individuals over 16 years was 3.40 kg (1.05-5.37 kg). A total of 554 milk tea samples were collected, with an average fluoride concentration of 2.25 mg/L, ranging from 0.82 to 12.18 mg/L. The daily per capita consumption of milk tea was 2 575 ml, leading to a daily per capita fluoride intake from milk tea of 5.79 mg, with a range of 2.92 to 13.06 mg. In ten counties, the daily per capita fluoride intake from milk tea exceeded the national health standard for total daily fluoride intake (3.50 mg). Conclusion The brick tea circulating in the Sanjiangyuan region is mainly composed of Kang and Fu bricks produced in Sichuan and Hunan, with excessive fluoride content in both brick tea and milk tea. The fluoride intake among the population exceeds safe levels, posing widespread health risks, necessitating the prompt implementation of effective preventive measures. [ABSTRACT FROM AUTHOR]

X‐ray excited persistent luminescence (XEPL) of lanthanide‐doped fluoride nanoparticles (NPs) holds promise for applications in back‐ground free bio‐medicine and flexible 3D imaging. However, it remains a daunting challenge to develop a universal and convenient route to greatly improve the XEPL performance of most fluoride nanosystems. Herein, for the first time, a versatile acid pickling strategy is proposed to greatly enhance the XEPL intensity of lanthanide‐doped fluoride NPs with different chemical compositions and activator types. Especially, after treatment with diluted HCl, the XEPL intensity of the NaYF4: Tb NPs with a mean particle size of ≈ 7 nm is enhanced ≈17.4 times. Mechanistic studies indicate the trap density in the NPs upon X‐ray irradiation is greatly enhanced after HCl treatment, contributing to the enhanced XEPL intensity. By integrating the HCl‐treated NPs into a scintillation film, the X‐ray image resolution is significantly increased from 6.3 to 11 lp mm−1, and the quality of delayed X‐ray images improved, particularly at low‐dose irradiation rates. These findings are expected to advance the development of high‐performance X‐ray‐activated persistent fluoride NPs and their applications for low‐dose high‐resolution X‐ray imaging. [ABSTRACT FROM AUTHOR]

Objective: To investigate the effects of sodium fluoride on the ameloblast and reveal the mechanism of dental fluorosis. Materials and methods: Mouse ameloblast‐like cell line (ALC) cells were treated with various concentrations of NaF, and subjected to Incucyte, fluorescence immunoassay, transmission electron microscopy, reverse transcription quantitative polymerase chain reaction (RT‐qPCR), western blot for autophagy examination, alkaline phosphatase and alizarin red staining for mineralization after osteogenic induction. Results: NaF exerts a dose‐dependent inhibitory effect on ALC cell growth. TEM and fluorescence immunoassay showed that 1.5 mM or higher concentrations of NaF could induce a fusion of lysosome and mitochondria, finally increasing the number of autophagosome. RT‐qPCR and western blot showed that the upregulation of autophagy related gene 13 (ATG13), downregulation of phosphorylated Unc‐51‐like kinase 1 (p‐ULK1) were found in NaF‐induced autophagy of ALC cells. The knockdown of ATG13 could rescue it as well as the expression of p‐ULK1 and LC3B. Besides, alizarin red staining showed that fluoride under these concentrations could promote the mineralization of ALC. Conclusions: The data show that fluoride in higher concentration can induce autophagy via the p‐ULk1/ATG13/LC3B pathway of ALCs than lower ones promote mineralization in vitro, which provides insight into the function of NaF in the autophagy and mineralization of ameloblast. [ABSTRACT FROM AUTHOR]

Purpose: Skeletal fluorosis (SF) results from chronic exposure to fluoride (F−) causing excessive aberrantly mineralized brittle bone tissue, fractures, and exostoses. There is no established treatment other than avoiding the source of F−. Still, excess F− can persist in bone for decades after exposure ceases. Case presentation: A 50-year-old woman presented with multiple, recurrent, low AQ2 trauma fractures yet high radiologic bone mineral density. Serum F− was elevated, and osteomalacia was documented by non-decalcified transiliac biopsy. She reported intermittently "huffing" a keyboard cleaner containing F− (difluoroethane) for years. Following cessation of her F− exposure, we evaluated the administration of the parathyroid hormone analog, abaloparatide, hoping to increase bone remodeling and diminish her skeletal F− burden. Conclusion: Due to the prolonged half-life of F− in bone, SF can cause fracturing long after F− exposure stops. Anabolic therapy approved for osteoporosis, such as abaloparatide, may induce mineralized bone turnover to replace the poorly mineralized osteomalacic bone characteristic of SF and thereby diminish fracture risk. Following abaloparatide treatment for our patient, there was a decrease in bone density as well as a reduction in F− levels. [ABSTRACT FROM AUTHOR]

Water pollution is currently a critical global issue. Various research groups have developed active adsorbent materials. This study aims to enhance the adsorption of water pollutants, particularly fluoride, by modifying the electronic structure of red soil through in-situ chemical oxidative polymerization techniques. The synthesized materials were characterized using techniques including powder XRD, FT-IR, UV spectroscopy, and Conductometer, followed by testing their adsorption performance. The XRD analysis revealed that while the crystal structures of embedded red soil remained amorphous, polyaniline (PANI) and PANI/red soil (RS) nanoparticles became polycrystalline. The maximum adsorption capacity (qmax) of fluoride ions by PANI/RS was determined to be 9.35 mg/g. Optimization experiments showed that PANI/RS exhibited maximum adsorption performance for fluoride ions under specific conditions: pH 4.0, a contact time of 50 min, temperature of 35 °C, and an initial concentration of 15 mg/L with 2 mg of adsorbent, achieving a removal efficiency of 99.9%. Both Langmuir and Freundlich isotherm models demonstrated a good fit with the experimental data, with R² values of 0.94 and 0.95, respectively. This suggests that PANI/RS is an effective adsorbent material for removing fluoride ions from wastewater. Overall, PANI/RS outperformed red soil alone, demonstrating potential for practical application in water treatment processes. [ABSTRACT FROM AUTHOR]

This research paper presents an innovative approach to fabricating enhanced-quality hierarchical surface micro-textures on Ti6Al4V alloy by synergistically employing in situ electrical discharge machining (EDM) and electrochemical machining (ECM) processes. The hierarchical structure encompasses three levels: a primary level at a few hundred micrometers, a secondary level at a few tens of micrometers, and a ternary level at sub-micrometer scales. Despite the precision achieved in generating the primary-level texture through EDM using a chemically patterned tool, inherent thermal damages and surface defects, such as micro-craters and irregularities, pose challenges. Unlike usual ex situ chemical or electrochemical post-processing methods, this study introduces in situ ECM post-processing (ECM) with the same patterned tool. This approach enhances the quality of EDMed surfaces without compromising geometrical accuracy, offering anisotropic dissolution along the feature depth. To ensure geometrical accuracy, an experimentally validated finite element method-based transient numerical simulation model is developed. This model accurately predicts the evolution of the feature profile during the ECM operation. Furthermore, ECM with a fluoride ion–containing electrolyte introduces additional secondary and ternary levels of hierarchical textures. Fluoride ions play a pivotal role in augmenting material removal during ECM, particularly in areas around micro-crevices and pores, shaping the secondary-level texture. [ABSTRACT FROM AUTHOR]

Drinking water containing optimal levels of cariostatic trace elements is an effective preventive approach against community-wide dental caries. This study aimed to (i) determine the concentrations of fluoride, copper, and zinc in commercially packaged and public tap water available in Qatar, (ii) assess the accuracy of the content of these cariostatic trace elements on commercial water brand labels, and (iii) check for seasonal fluctuations in the levels of these trace elements in commercial and public water samples. Duplicate samples from 20 commercial and six public tap water sources were collected once in the summer and winter seasons. Water samples were evaluated for fluoride concentration using ion chromatography (IC), whereas copper and zinc concentrations were estimated using inductively coupled plasma mass spectrometry (ICP-MS). The fluoride content of all commercial and public water samples was below the 0.25 mg/L detection limit of the IC instrument. Commercial water brands had copper and zinc levels below the ICP-MS detection limits (1.22 μg/L for copper and 0.24 μg/L for zinc). Copper levels in the public water samples ranged from <1.22 μg/L to 11 μg/L. Zinc levels in the public water samples ranged from 5 μg/L to 40 μg/L. Thirteen commercial water brands labelled their fluoride content, with most showing labelled fluoride levels <0.1 mg/L, consistent with the results of this study. The difference in trace element content between the summer and winter water samples was not statistically significant (P > 0.05). Lower optimal cariostatic trace element content in the drinking water in Qatar could be a reason for the exceptionally high prevalence of dental caries. The results of this study could lead to public health advocacy for supplementing drinking water in Qatar with cariostatic trace elements that could potentially lower the prevalence of dental caries. [ABSTRACT FROM AUTHOR]

To evaluate the effect of 1100 ppm F toothpastes supplemented with micrometric or nanosized β-CaGP (β-CaGPm/β-CaGPn) on artificial enamel remineralization, using a pH cycling model. Enamel blocks with artificial caries were randomly allocated into ten groups (n = 10), according to the toothpastes: without fluoride/β-CaGPm/β-CaGPn (negative control); 1100 ppm F (1100F); 1100F plus 0.125%, 0.25%, 0.5%, and 1.0% of β-CaGPm or β-CaGPn. The blocks were treated 2×/day with slurries of toothpastes. After pH cycling, the percentage of surface hardness recovery (%SHR); integrated loss of subsurface hardness (ΔKHN); integrated mineral loss (ΔIMR); fluoride (F), calcium (Ca), and phosphorus (P) concentrations in the enamel; polydispersity index (PdI); and zeta potential (Zp) were determined. The data were analyzed by ANOVA (p < 0.001). For Zp/PdI, no significance was observed when comparing the means (p > 0.001). The treatment with 1100F-0.25%β-CaGPn led to %SHR ∼57 higher when compared to the 1100F group (p < 0.001). The lowest ΔKHN was observed for the 1100F-0.25%β-CaGPn group (p < 0.001). The ΔIMR was lower (∼201%) for the 1100F-0.25%β-CaGPn when compared to 1100F (p < 0.001). The association of β-CaGPm and β-CaGPn to 1100F did not influence its F concentration (p > 0.001). The highest increase in Ca and P was observed for 1100F-0.25%β-CaGPn (p < 0.001). The addition of 0.25%β-CaGPn to 1100F toothpaste was able to promote an additional remineralizing effect of artificial caries lesions. [ABSTRACT FROM AUTHOR]

The research exploiting the ability of dental materials to induce or prevent secondary caries (SC) development still seems inconclusive. Controlling bacterial adhesion by releasing bacteriostatic ions and improving the surface structure has been suggested to reduce the occurrence of SC. This paper analyses the impact of five distinctively composed dental materials on cariogenic biofilm formation. Forty-five specimens of three composites (CeramX Spectra ST, Admira Fusion, Beautifil II) and two glass–ionomers (Fuji II LC, Caredyne Restore), respectively, were incubated in bacterial suspension composed of Streptococcus mutans, Lactobacillus acidophilus, Streptococcus mitis, Streptococcus sanguinis, and Streptococcus salivarius at pH 7.0 and 5.5. Coverslips were used as a control. Adhered bacteria were collected after 2, 4, 6, 12, 24, and 48 h and analyzed using quantitative polymerase chain reaction (qPCR). Fluoride leakage was measured at each collection. The specimens' surface topography was assessed using interferometry. In the present study, surface roughness seemed to have a partial role in bacterial adhesion and biofilm formation, together with chemical composition of the materials tested. Despite differences in fluoride leakage, biofilm accumulation was similar across materials, but the number of adhered bacteria differed significantly. A release of other ions may also affect adhesion. These variations suggest that certain materials may be more prone to initiating secondary caries. [ABSTRACT FROM AUTHOR]

This research explores the potential of use of waste scaling deposition from electric geysers (EGWS) to synthesize calcium oxide and address fluoride and nitrate contamination in water. The study adopts a circular economy framework by utilizing the synthesized calcium oxide to modify corn cob biochar through ball‐milling, creating a cost‐effective and environmentally sustainable adsorbent. The adsorbent is characterized and pHpzc analysis of CaO@CBC indicates sustained high adsorption capacities for nitrate and fluoride across a broad pH range (2–11). The adsorption kinetics follow a pseudo‐second‐order model, indicating chemisorption mechanisms. The Langmuir isotherm model fits well, showing high maximum adsorption capacities of 18.36 mg g−1 for fluoride and 19.27 mg g−1 for nitrate, surpassing those reported for other materials. Thermodynamic studies indicate that the uptake reactions of fluoride and nitrate are spontaneous and exothermic. Results from pH studies, XPS analysis, and FTIR offer insights into the adsorption mechanism by suggesting electrostatic attraction, inner‐sphere complexation, and ion exchange. The research establishes the efficacy of CaO‐impregnated biochar derived from electric geyser waste in removing fluoride and nitrate, offering a sustainable solution for water pollution. This work breakthroughs the development of efficient and eco‐friendly adsorbents for water treatment, aligning with the principles of a circular economy. [ABSTRACT FROM AUTHOR]

Background: Community water fluoridation is an effective public health strategy for preventing dental caries, yet. Concerns exist about potential health problems. This study explores associations between tap water fluoride levels and pediatric disease burden, as well as neurodevelopmental outcomes at 6 years of age. Methods: This nationwide population-based cohort study included children born in Korean cities with and without tap water fluoridation projects, between 2006 and 2012, aiming for a fluoride concentration of 0.8 ± 0.2 mg/L in treated tap water. Data from the National Health Insurance Service were used, spanning from birth to 2018. The relationship between exposure to fluoridated tap water and incidence of 16 childhood diseases that were previously identified as potentially linked to fluoride exposure were examined. Additionally, we evaluated the neurodevelopmental outcomes across various domains, including gross motor, fine motor, cognition, language, social skills, and self-help functions. These assessments were performed using data from a comprehensive national health screening program for children aged six years. Results: A fluoride-unexposed group included 22,881 children, whereas a fluoride-exposed group comprised 29,991 children (52% males). Children in the fluoride-exposed group had a decreased risk of dental caries and bone fractures [hazard ratio (95% confidence interval, CI), 0.76 (0.63–0.93) and 0.89 (0.82–0.93), respectively] and increased risk of hepatic failures [1.85, (1.14–2.98)] compared to those in the unexposed group. Additionally, the risk ratio of abnormal neurodevelopmental screening outcomes increased by 9%, but this was statistically uncertain (95% CI, 0.95–1.26). Conclusions: Fluoridated tap water was associated with an increased risk of hepatic failure but a decreased risk of bone fractures in children. The association between fluoridated tap water and neurodevelopmental screening outcomes at 6 years remains unclear, highlighting the need for further studies to clarify this association. [ABSTRACT FROM AUTHOR]

Background: The oral cavity is an important but often overlooked reservoir for Staphylococcus aureus. The effective control and prevention of S. aureus colonization and infection in the oral and maxillofacial regions are crucial for public health. Fluoride is widely used in dental care for its remineralization and antibacterial properties. However, its effectiveness against S. aureus has not been thoroughly investigated. Objectives: This study aimed to evaluate the potential of combining sodium fluoride (NaF) with compounds to enhance its antibacterial and antibiofilm effects against S. aureus. Method: We found that a urea derivative significantly enhances the efficacy of fluoride by promoting the retention of fluoride ions within the cells. The synergistic antibacterial and antibiofilm effects of BPU with NaF were confirmed through various assays, including checkerboard assays, time-kill assays, and growth curve analysis. These findings were further supported by additional methods, including transmission electron microscopy (TEM), in silico simulations, and gene overexpression studies. Results: These findings suggest that targeting fluoride ion membrane exporters could enhance antibacterial efficacy. When combined with fluoride, 1,3-Bis [3,5-bis(trifluoromethyl)phenyl]urea (BPU) showed increased effectiveness in inhibiting S. aureus growth and reducing established biofilms. Conclusions: This novel combination represents a promising therapeutic strategy for treating biofilm-associated S. aureus infections, offering a new strategy in oral healthcare. To fully evaluate the clinical potential of this synergistic therapy, further in vivo studies are essential. [ABSTRACT FROM AUTHOR]

Sodium fluoride (NaF) ingestion has several detrimental effects in humans and rodents. NaF mechanisms of toxicity include perturbation of intracellular redox homeostasis and apoptosis. Betaine (BET) is a modified amino acid with anti-inflammatory, antioxidant, and anti-apoptotic properties. This study investigates BET's effect on NaF-induced hepatorenal toxicities in rats. Experimental rats (n = 30) were randomly assigned to groups (n = 6) and treated by gavage for 28 days. Group I (2 mL of distilled water), Group II (NaF: 9 mg/kg) alone, Group III: (BET: 100 mg/kg), Group IV: (NaF: 9 mg/kg and BET 1: 50 mg/kg), and Group V: (NaF: 9 mg/kg and BET 2: 100 mg/kg). Our findings revealed significantly (p < 0.05) increased hepatic transaminase activities alongside creatinine and urea levels following NaF-alone treatment in addition to increased oxidative status, lipid peroxidation, reactive oxygen and nitrogen species, decreased superoxide dismutase, catalase, glutathione-s-transferase, glutathione peroxidase, glutathione, and total sulfhydryl groups. The reduced levels of nuclear factor erythroid 2-related factor-2 and the activities of heme oxygenase-1, thioredoxin, and thioredoxin reductase in NaF-alone treated rats equally compromised cellular molecular responses to oxidative stress. Also, NaF increased (p < 0.05) hepatorenal inflammatory biomarkers-nitric oxide, interleukin-10, myeloperoxidase, and xanthine oxidase. Furthermore, caspase-3 and caspase-9 were increased (p < 0.05) in rats treated with NaF alone. Contrastingly, BET was observed to alleviate the harmful effects of NaF. Treatment with BET mitigated NaF-induced oxido-inflammatory responses and apoptosis in the experimental rat's hepatorenal system. The study demonstrates the potential of BET to abate NaF-induced hepatorenal toxicity. [ABSTRACT FROM AUTHOR]

Good quality water for human consumption, irrigation, and industrial use is very important. Today, around the world, water is contaminated by natural processes and human activities. This study aimed to evaluate the suitability of groundwater for drinking and irrigation, identify the source of fluoride and nitrate contamination, and assess the human health risks around the Cauvery River basin in southern India. A total of 30 groundwater samples were collected and analyzed for hydrochemical parameters, including EC, TDS, pH, Ca, Mg, Na, K, HCO3, Cl, SO4, NO3, and F−. The majority of groundwater samples in the study area are used for drinking and irrigation. The pH of groundwater in the study area was observed to be dominantly alkaline. The levels of TDS, Ca, Na, K, F, and TH exceeded the permissible limits recommended by BIS and WHO. Fluoride and nitrate levels in groundwater exceeded the permissible limits for drinking purposes in 43% and 50% of the samples, respectively. The excessive concentration of fluoride and nitrate in groundwater could pose serious human health problems. Fluoride and nitrate concentrations in groundwater vary between 0.1 and 2 mg/l and 12 and 95 mg/l, respectively. Based on the computation of the drinking water quality index, about 73% of groundwater samples were classified as excellent to good. Health risk was assessed for infants, children, and adults using non-carcinogenic risk indices such as hazard quotients (HQ), hazard indexes (HI), total hazard indices (THI), and carcinogenic risk indices (CR). Infants, children, and adults have different total hazards indexes ranging from 1.508 to 5.733, 1.579 to 6.003, and 0.011 to 0.046, respectively. Health risk assessment results indicated that the hazard index and hazard quotient were above the recommended limit of > 1 in most of the samples for infants and children. Non-carcinogenic risk and carcinogenic risks were more likely to affect infants and children rather than adults through ingestion of contaminated water. [ABSTRACT FROM AUTHOR]

Fluoride (F) is a trace element that is essential to the human body and occurs naturally in the environment. However, a deficiency or excess of F in the environment can potentially lead to human health issues. The pseudototal amount of F in soil often does not correlate directly with the F content in plants. Instead, the F content within plants tends to have a greater correlation with the bioavailable F in soils. In large-scale soil surveys, only the pseudototal elemental content of soils is typically measured, which may not be highly reliable for developing agricultural zoning plans. There are significant variations in the ability of different plants to accumulate F from soil. Additionally, due to variations in soil elemental absorption mechanisms among different plant species, when multiple crops are grown in an area, it is typically necessary to study the elemental absorption mechanisms of each crop. To address these issues, in this study, we examined the factors influencing F bioaccumulation coefficients in different crops based on 1:50,000 soil geochemical survey data. Using the random forest algorithm, four indicators—bioavailable P, bioavailable Zn, leachable Pb, and Sr—were selected from among 29 parameters to predict the F content within crops to replace bioavailable F in the soil. Compared with the multivariate linear regression (MLR) model, the random forest (RF) model provided more accurate and reliable predictions of the fluoride content in crops, with the RF model’s prediction accuracy improving by approximately 95.23%. Additionally, while the partial least squares regression (PLSR) model also offered improved accuracy over MLR, the RF model still outperformed PLSR in terms of prediction accuracy and robustness. Additionally, it maximized the utilization of existing geochemical survey data, enabling cross-species studies for the first time and avoiding redundant evaluations of different types of agricultural products in the same region. In this investigation, we selected the Xining-Ledu region of Qinghai Province, China, as the study area and employed a random forest model to predict the crop F content in soils, providing a new methodological framework for crop production that effectively enhances agricultural quality and efficiency. [ABSTRACT FROM AUTHOR]

The Ngari region has many important rivers and is critical to water resource security and water resource continuity in China and even in adjoining Asian countries. However, the spatial distribution and monthly variation in local water quality have been poorly understood until recently. In this study, the spatial–temporal variations of 12 water quality parameters, including pH, dissolved oxygen (DO), permanganate index (IMn), chemical oxygen demand (COD), five-day biochemical oxygen demand (BOD5), ammonia nitrogen (NNH3), total nitrogen (Ntotal), total phosphorus (Ptotal), copper (Cu), fluoride (F), arsenic (As) and cadmium (Cd), were determined from samples collected monthly at 22 water cross-sectional sites in the Ngari region in 2020. The surface water pollution in the southern Ngari region was the most serious, and the water pollution level in winter was higher than that in the other seasons. As (0.0781 ~ 0.6154 mg/L) and F (1.05 ~ 4.64 mg/L) were the main exceedance factors derived from the recharge of high arsenic and fluoride geothermal water and weathering of As and F-bearing minerals. The hazard quotient and carcinogenic risk for As and F at the five contaminated sampling sites indicated potential health risks and even carcinogenicity to local populations. The hydrochemistry types of the lakes and rivers in the Ngari region were mainly chloride water and carbonate water. The results from this study can provide a scientific basis for the prevention and control of surface water pollution in the Ngari region and contribute to subsequent research on the ecology of water bodies. [ABSTRACT FROM AUTHOR]

Waste marble powder (WMP) is a rich source of calcium and magnesium salts having an affinity for fluoride ions and therefore serves as a good defluoridation agent. Hydroxyapatite was synthesized from WMP generated by the marble processing industry to make an adsorbent for drinking water defluoridation. The synthesized marble hydroxyapatite (MA-Hap LR) powder was further formed into 2–3 mm pellets by extrusion spheronization technique using a polyvinyl alcohol binder. Continuous column defluoridation studies were conducted to obtain optimized column parameters such as input fluoride concentration, column inflow rates, optimum pellet size, and adsorbent bed parameters to obtain maximum fluoride adsorption capacity. The best breakthrough column performance was a maximum adsorption capacity of 1.21 mg/g, treating 10 mg/L fluoride concentration. The optimized column flow rate was at 1 LPH using an adsorbent bed height of 25 cm, which processed 28.5-bed volumes at an adsorbent exhaustion rate of 7.4 g/L. The column breakthrough performance data were fit into various kinetic models (Thomas model and Yoon–Nelson model) to describe adsorption kinetics and obtain correlation coefficients. Thomas's model fitted well with a high correlation coefficient value. Modelling studies indicate MA-Hap as a promising adsorbent for drinking water treatment, and optimum column design parameters were identified for scale-up for real applications. [ABSTRACT FROM AUTHOR]

Background: fluoride is a beneficial ion that has been used in various fields, from industrial products to therapeutics. However, due to its narrow therapeutic index, fluoride sometimes acts as a toxic agent at relatively higher concentrations in the human body. Based on the interest in genetic stability, its cytotoxic effects have been investigated mainly in nucleated, adherent cells, such as fibroblasts. However, the sensitivity of blood cells, especially anucleate platelets, to fluoride is poorly understood. To fill this gap in the literature, we investigated the effects of relatively low levels of fluoride on platelet energy metabolism, function, and viability. Methods: Platelet-rich plasma (PRP) was prepared from 15 non-smoking healthy male adults (age: 28-63) and treated with NaF (0.5 or 1.0 mM) in microtubes for up to 3 days. Platelet function was evaluated based on aggregation and adhesion activities. Platelet energy metabolism was evaluated based on intracellular ATP levels, extracellular lactate levels, and respiration activities. The mitochondrial membrane potential (Em) and localization of reactive oxygen species (ROS) were visualized using cytochemical methods. Platelet viability was evaluated by cell counting and tetrazolium reduction. Result: NaF (1 mM) significantly reduced platelet viability and inhibited functions. Behind these phenomena, NaF substantially decreased mitochondrial Em and increased ROS production along with significant decreases in oxygen consumption and ATP levels. Simultaneously, NaF increased the lactate levels. Although not statistically significant, similar effects were observed at 0.5 mM NaF. Conclusion: At relatively low levels, NaF has the potential to attenuate platelet function probably primarily through the inhibition of mitochondrial energy generation. Cytotoxicity may be directly related to ROS production. These findings suggest that when used topically, for example, for caries prevention in the oral cavity, NaF could interfere with wound healing and tissue regeneration by endogenous and exogenously added platelets in the form of PRP. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate chitosan (CS)-based formulations loaded with 5% sodium fluoride (NaF) and/or 10% nanohydroxyapatite (nHA) to remineralize the demineralized primary tooth enamel surface. Ninety enamel blocks were demineralized and were divided into six groups (n = 15): (1) CS-based hydrogel, (2) CS-based hydrogel loaded with NaF, (3) CS-based hydrogel loaded with nHA, (4) CS-based hydrogel loaded with NaF and nHA, (5) 5% NaF varnish, and (6) negative control with no intervention. After intervention, the specimens were pH cycled by 2 h immersion in demineralizing solution and 22 h immersion in remineralizing solution for 8 days. The remineralization effects were evaluated by Vickers microhardness measurements and field emission scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (FESEM-EDS). The best mean ± SD percentage microhardness recovery in remineralized enamel (%REMH) was found in group 4 (56.90 ± 5.49). The %REMH of groups 2 (30.74 ± 3.51) and 5 (29.23 ± 5.65) were statistically the same (p = 0.943). FESEM images confirmed partial coverage of the porous demineralized enamel with a newly formed mineralized layer. Based on EDS findings, the Ca/P ratio values of the treated enamel surfaces with CS-based hydrogels ranged between 1.71 and 1.87, and the highest F content was noticed in group 2 (1.02 ± 0.03). Although, all tested CS-based hydrogels demonstrated the potential to repair demineralized enamel, nHA- and NaF-containing CS-based hydrogel showed the highest remineralization effect. We infer that this new hybrid hydrogel is a potentially useful dental material for tooth biomineralization. [ABSTRACT FROM AUTHOR]

Background: Fluoride plays a vital role in preventing dental caries, with its addition to oral care products significantly promoting oral hygiene. A no-rinse brushing method aims to increase fluoride retention in the oral cavity, as rinsing with water decreases fluoride levels in saliva, which could affect remineralization. While the no-rinse brushing method holds promise for improving fluoride retention in the oral cavity, critical inquiries persist regarding its safety. This study investigated the kinetics of oral fluoride and potential risks to fully assess its effectiveness and implications for oral health. Methods: Ten healthy adults participated in a crossover study comparing the no-rinse with the rinse method. All subjects followed American Dental Association (ADA) brushing guidelines. Levels of fluoride in saliva (supernatant and sediment) and urine were measured over time, and plasma fluoride was measured one hour after brushing. Pharmacokinetic parameters were also calculated from the data. Results: Participants using the no-rinse method had higher fluoride levels in supernatant immediately and up to 30 min post-brushing compared to the rinse method. Fluoride levels in sediment were higher only immediately after brushing. The total fluoride concentration in saliva remained elevated for up to 5 min with the no-rinse method. Systemic fluoride absorption showed no significant difference between the two methods based on blood and urine analysis. Conclusion: This research indicates that the no-rinse method can enhance fluoride retention in the oral cavity for up to 30 min after a single brushing. In addition, our findings suggest that this method does not significantly influence systemic fluoride levels or toxicity. Registry: Thai Clinical Trials Registry, TCTR (http://thaiclinicaltrials.org). Clinical trial registration number: TCTR20231104001 (4/11/2023). [ABSTRACT FROM AUTHOR]

Objective: The use of fluoride is one of the few evidence-based preventive of dental caries. Fluoride rejection is a growing public health concern. Public health researchers need to develop fluoride rejection screening tools, diagnostic tools, and evidence-based strategies for optimal preventive dental care decisions. This study aimed to develop a Fluoride Acceptance Scale (FAS). Material and Method: Six hundred and sixty-two volunteers were included for the research. An item pool consisting of 15 items was developed as a result of literature review. A 6-point Likert Scale ranging from 0 to 5 was used in this scale. Four items were removed at the content validity stage and one item at the internal consistency stage. Internal consistency stage 10 of them were accepted for the scale based on Cronbach's Alpha values. The mean Content Validity Indeks value of the scale was calculated as 0.95. The data were analyzed using SPSS Statistics Pack version 22.0 (IBM, Armonk, NY). Results: In this study, Turkish Fluoride Acceptance Scale was developed to measure fluoride acceptance. The scale consisted of 10 questions and 2 factors: A: Fluoride Benefit and Protection (6 questions), B: Opposition to Fluoride (4 questions). The Cronbach's Alpha was 0.862, Kaiser-Mayer-Olkin was 0.826. Factor load values of all items (10 items) were found to be 0.5 and above. Conclusion: The FAS can be used to assess fluoride acceptance in an easy and quick way and can assist in the development of health policies. [ABSTRACT FROM AUTHOR]

NaAlCl4 solid electrolyte is a highly promising solid-state sodium-ion electrolyte with significant application potential. However, most studies on the modification of such material have focused on the impact of cation doping on performance, and the effects of anion doping remain unknown. In this work, fluoride (F−) and borohydride (BH4−) were successfully introduced into NaAlCl4 using a mechanical ball milling method, resulting in the synthesis of NaAlCl4−xFx (x = 0, 0.1, 0.3, 0.5, and 0.7) and NaAlCl4−x(BH4)x (x = 0.1 and 0.3). These derivatives maintain the same orthorhombic structure as NaAlCl4. Electrochemical measurements validate the feasibility of F− and BH4− doping for modifying the NaAlCl4 electrolyte. X-ray photoelectron spectroscopy (XPS) analyses demonstrate that the fluorinated Na/NaAlCl3.5F0.5 interphase formed during cyclic voltammetry (CV) measurements, this prevented further side reactions. This work reveals that F− and BH4− doping exhibit similar electrochemical effects, holds profound practical significance for future research in modifying halide-based sodium ion solid electrolytes. [ABSTRACT FROM AUTHOR]

Poly-aluminium chloride (PAC) sludge is a waste product created during drinking water treatment, usually generated in large quantities and typically landfilled. More attention must be directed to environmental-friendly management and economically sustainable of Al-based sludge. In this work, a low-cost and environmental-friendly adsorbent prepared by sodium alginate coated PAC sludge (SPS) was investigated for fluoride removal. Basic preparing parameters including heating temperature (200–800°C), sodium alginate concentration (0.5–5 wt%), particle size (1–2 mm, 2–3 mm, 3–4 mm) and operating parameters including dosage (1–14 g/L), solution pH (4–11), temperature (10–35°C), co-existing anions (NO3−, Cl−, SO42-, PO43-) were examined to evaluate the optimum defluoridation capacity. The prepared SPS adsorbents reached a high removal efficiency of 95.6% with initial fluoride concentration of 10 mg/L, dose of 8 g/L, contact time of 24 h, pH value of 7 and temperature of 10°C. The kinetic study indicated that fluoride adsorption followed the pseudo-second-order kinetics well (R2 = 0.9942), and adsorption isotherms can be well described by Freundlich model (R2 = 0.9952). Thermodynamic studies showed the fluoride adsorption was spontaneous and exothermic. The elements and functional groups of SPS adsorbents were analysed by using EDS and FTIR, respectively. The adsorption mechanism involved physisorption, ligand-exchange and electrostatic attraction. According to N2 adsorption–desorption isotherm, the SPS was mesoporous material which facilitated the adsorption of fluoride ions. Also, aluminium presented in form of Al-OH in SPS adsorbents had significant contribution in fluoride adsorption. The concentration of the residual aluminium ions was 4.48 × 10−3 mg/L which is lower than the China Drinking Water Standard. The encouraging results of this preliminary study indicated that SPS is an environmental-friendly and cost-effective treatment option for groundwater with fluoride pollution. [ABSTRACT FROM AUTHOR]

Objective: This retrospective cohort study compared differences in age one dental visit use and age at first dental visit according to fluoride varnish receipt at the pediatric medical home. Methods: Enrollment and claims data were used from Partners For Kids, a pediatric accountable care organization covering Medicaid‐enrolled children living in 47 of 88 counties in Ohio. The main outcomes were having an age one dental visit and the mean age at first dental visit. Descriptive statistics and bivariate comparisons were applied. Results: Among 17,675 children, 2.8% had an age one dental visit. The mean age at first dental visit was 4.8 years. Children who received fluoride varnish from their medical home (12% of study population) were significantly younger at their first dental visit (4.1 vs. 4.9 years, p < 0.001). Conclusion: Despite longstanding recommendations for the age one dental visit, very few Medicaid‐enrolled children in Ohio had one. The pediatric medical home lowered the age of first dental visit. [ABSTRACT FROM AUTHOR]

Objective: Fluoride-induced oxidative stress and synaptic dysfunction pose significant threats to neural health. This research investigated the potential ameliorative effects of Strychnos potatorum seed (SPS)-treated water on fluoride-induced neurotoxicity using SK-N-SH cells as an in vitro model system. Methods: To elucidate the underlying molecular mechanisms involved, we focused on the brain-derived neurotrophic factor (BDNF)-TrkB signaling pathway, a crucial modulator of synaptic plasticity, and neuroprotection. Results: Our study revealed that Strychnos potatorum seed water administered for 48 to 96 h improved cell viability, as evidenced by enhanced cell survival rates and preserved cellular architecture, and that SPS-treated water effectively attenuated fluoride-induced oxidative stress, as evidenced by a reduction in reactive oxygen species (ROS). Furthermore, SPS-treated water significantly improved synaptic function, as indicated by enhanced expression of synaptic proteins, including synaptophysin (SYN 1) and postsynaptic density 95 (PSD-95). SPS water upregulated BDNF expression and promoted the activation of its cognate receptor, TrkB, in fluoride-challenged SK-N-SH cells. In addition, SPS-treated water-mediated regulation of the mitogen-activated protein kinase (MAPK) signaling cascade was observed, with increased phosphorylation of extracellular signal-regulated kinase (ERK). Conclusion: These results suggest that SPS-treated water exerts neuroprotective effects against fluoride-induced neurotoxicity by targeting the MAPK-mediated BDNF-TrkB signaling pathway. However, further research is needed to investigate the effectiveness of SPS in vivo and its potential use as a neuroprotective agent. [ABSTRACT FROM AUTHOR]

Fluoride (iF) is an inorganic element commonly present in groundwater in central Mexico and is considered a health risk when it exceeds the Mexican drinking water standard of 1.5 mg/L. Prolonged exposure to iF can cause various adverse health effects, such as dental fluorosis and neurological effects, particularly in children. A rapid and cost-effective strategy to identify possible areas where the resident population may be at risk of exposure to this contaminant is the health risk estimation methodology of the Pan American Health Organization (PAHO). The aim of this study was to estimate the environmental risk of iF exposure in residents of Jerez, Zacatecas, Mexico, and subsequently construct risk maps to identify areas of the city where there is a higher risk of exposure. Fifty-five tap water samples were collected from households to determine iF concentrations using the ion-selective electrode method. Based on these environmental values, the hazard quotient (HQ) was estimated following the health risk estimation methodology. Subsequently, risk maps were generated from these values to visualize the spatial distribution of high-risk areas within the city. The iF concentrations in tap water ranged from 1.3 to 7.3 mg/L (ppm), with only one sample below the standard of 1.5 mg/L. We estimated HQ values ranging from 0.63 to 3.73. Exposure to iF in tap water is a health problem that must be addressed, necessitating risk communication actions that enable the population to safeguard its health through simple measures, thereby avoiding future health costs. [ABSTRACT FROM AUTHOR]

The aim of this study was to examine the association between fluoride exposure and bone mineral density (BMD) in children and adolescents. We used data from the National Health and Nutrition Examination Survey (NHANES) 2015–2016. The fluoride concentrations in the water samples, plasma samples, and urine samples were measured electrometrically using an ion-specific electrode. Total body less head BMD (TBLH BMD) was measured using dual-energy X-ray absorptiometry (DXA). Weighted generalized linear regression models and restricted cubic splines (RCS) regression models were used to analyze the relationships between the three types of fluoride exposure and TBLH BMD. We performed subgroup analyses stratified by sex. A total of 1413 US children and adolescents were included in our study. In our linear regression models, we found inverse associations between fluoride concentrations in water and plasma and TBLH BMD. Additionally, we discovered a non-linear association between fluoride concentrations in water and plasma and TBLH BMD. No significant association or non-linear relationship was found between urine fluoride levels and TBLH BMD. This nationally representative sample study provides valuable insight into the intricate connection between fluoride exposure and skeletal health in children and adolescents. [ABSTRACT FROM AUTHOR]

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Exposure to excessive concentrations of fluoride in potable water is harmful to human health; therefore, its limitation is deemed necessary. Among the commonly applied technologies, adsorption is selected, as it is a highly effective, simple, and economically efficient treatment. In the present study, several combinations of chitosan (CS), orange peels (OP), activated carbon (AC), and MgO were synthesized and tested as adsorbents in order to find the most effective derivative for fluoride extraction. The impact of the adsorbent dosage, pH level, contact time, and initial concentration was investigated to assess the feasibility of the chitosan/orange peels/activated carbon@MgO composite. According to the results, the modification of chitosan with AC, OP, and MgO in a unique adsorbent (CS/OP/AC@MgO), especially in acidic conditions (pH 3.0 ± 0.1) by using 1.0 g/L of the adsorbent, demonstrated the highest efficiency in F removal, up to 97%. The pseudo-second (PSO) order model and Langmuir isotherm model fit better to the experimental results, especially for CS/OP/AC@MgO, providing a Qm = 26.92 mg/g. Thermodynamic analysis confirmed the spontaneous nature of the adsorption process. The structure and morphology of the modified OP/CS@AC-Mg were extensively characterized using BET, XRD, FTIR, and SEM techniques. [ABSTRACT FROM AUTHOR]

This study investigated the efficacy of Isomalt-containing toothpaste in preventing development of dental caries. Methods: Human dental enamel slabs were allocated to six groups (30/group) at random: De-ionized distilled water (DDW), and toothpaste containing 10% Isomalt, 1100 ppm fluoride, 0.05% cetylpyridinium chloride [CPC] (ICT); 10% Isomalt, 1100 ppm fluoride (IT); 10% Isomalt, 1100 ppm fluoride, 1.5% Sodium lauryl sulfate [SLS] (IST); 1100 ppm fluoride only (FT); 1100 ppm fluoride with SLS (FST). The enamel slabs were exposed to caries development via plaque growth in a Microbial Caries Model for 7 days. Toothpastes were applied as slurries (one toothpaste–three DDW) for 2 min twice daily. Demineralization was measured as the change in surface microhardness (ΔSMH) and amount of mineral lost (∆Z), and these metrics were assessed using Transverse Microradiography. Intra-group (SMH) and intergroup (%∆SMH and ∆Z) comparisons were paired t-test and Tukey's test (α = 0.05), respectively. Results: With SMH, demineralization was found to be significant (p < 0.001) in all groups compared to sound enamel baseline, except ICT group. With %ΔSMH, all other groups had significantly (p < 0.001) less demineralization compared to DDW. Significantly (p < 0.001) greater demineralization was observed in IT, FT and FST compared to ICT, and no significant difference was observed between IST and ICT or FT. With ∆Z, relative to the DDW group, the inhibition of demineralization was significant (p < 0.0001) in all groups at varying percentages. Conclusions: Toothpaste containing 10% Isomalt, 1100 ppm fluoride, and 0.05% CPC demonstrated greater efficacy in inhibiting caries development amid dental plaque compared to toothpaste containing only 1100 ppm fluoride. [ABSTRACT FROM AUTHOR]

Fluoride and aluminum are ubiquitous toxic metals with adverse reproductive effects. The citrus flavonoid hesperidin has protective activities but poor solubility and bioavailability. Nanoparticulate delivery systems can improve flavonoid effectiveness. We conducted this study to prepare a pH-responsive chitosan-based nanogel for hesperidin delivery and evaluate its effectiveness against sodium fluoride (NaF) and aluminum chloride (AlCl3) induced testicular toxicity in mice. The nanogel was synthesized using 2 kGy gamma irradiation, enabling a size under 200 nm and enhanced hesperidin release at pH 6 matching testicular acidity. Male mice received 200 mg/kg AlCl3 and 10 mg/kg NaF daily for 30 days. Hesperidin nanogel at 20 mg/kg was administered orally either prophylactically (pretreatment) or after intoxication (posttreatment). The results showed that AlCl3 + NaF induced severe oxidative stress, hormonal disturbance, apoptosis, and endoplasmic reticulum stress, evidenced by significant changes in the studied parameters and testicular histological damage. Hesperidin nanogel administration significantly inhibited oxidative stress markers, restored luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone levels, and alleviated tissue damage compared to the intoxicated group. It also downregulated the expression level of pro-apoptotic genes Bax, caspase-3, caspase-9, and P38MAPK, while upregulating the expression level of the anti-apoptotic BCL2 gene. Endoplasmic reticulum stress sensors PERK, ATF6, and IRE-α were also downregulated by the nanogel. The chitosan-based nanogel enhanced the delivery and efficacy of poorly bioavailable hesperidin, exhibiting remarkable protective effects against AlCl3 and NaF reproductive toxicity. This innovative nanosystem represents a promising approach to harnessing bioactive phytochemicals with delivery challenges, enabling protective effects against chemical-induced testicular damage. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa) is one of the essential staple foods highly consumed globally, with nearly 40% to 45% of the global population estimated to consume rice. Therefore, consumable rice should have low levels of harmful elements. This study investigates fluoride (F¯) content in raw rice (uncooked rice) and evaluates Probabilistic Health Risk Assessment (PHRA) through Monte Carlo simulation (MCS) due to the consumption of F¯ enriched rice. The literature review reveals that limited studies have been conducted on the investigation of F¯ in raw rice. The fluoride (F¯) concentration in raw rice varies across the studied countries, indicating the need for additional studies to facilitate a more accurate comparison. The F¯ content in raw rice varied among the studied countries, making it difficult to definitively state that the concentration of F¯ in one country is higher. However, the concentration of F¯ in raw rice in India is notably elevated. This study also highlighted the importance of investigating the F¯ content in raw rice. The study will be highly helpful for policymakers to formulate guidelines for water used for irrigation. [ABSTRACT FROM AUTHOR]

Fluorine (19F) NMR is emerging as an invaluable analytical technique in chemistry, biochemistry, structural biology, material science, drug discovery, and medicine, especially due to the inherent rarity of naturally occurring fluorine in biological, organic, and inorganic compounds. Here, we revisit the under-reported problem of fluoride leaching from new and unused glass NMR tubes. We characterised the leaching of free fluoride from various types of new and unused glass NMR tubes over the course of several hours and quantify this contaminant to be at micromolar concentrations for typical NMR sample volumes across multiple glass types and brands. We find that this artefact is undetectable for samples prepared in quartz NMR tubes within the timeframes of our experiments. We also observed that pre-soaking new glass NMR tubes combined with rinsing removes this contamination below micromolar levels. Given the increasing popularity of 19F NMR across a wide range of fields, increasing popularity of single-use screening tubes, the long collection times required for relaxation studies and samples of low concentrations, and the importance of avoiding contamination in all NMR experiments, we anticipate that our simple solution will be useful to biomolecular NMR spectroscopists. [ABSTRACT FROM AUTHOR]