Identifying the genetic mechanism of medium-low temperature fluoride-enriched geothermal groundwater by the self-organizing map and evaluating health risk in the Wugongshan area, southeast China.

Fluoride-enriched groundwater is a serious threat for groundwater supply around the world. The medium-low temperature fluoride-enriched geothermal groundwater resource is widely distributed in the circum-Wugongshan area. And the fluoride concentration of all geothermal samples exceeds the WHO permissible limit of 1.5 mg/L. The Self-Organizing Map method, hydrochemical and isotopic analysis are used to decipher the driving factors and genetic mechanism of fluoride-enriched geothermal groundwater. A total of 19 samples collected from the circum-Wugongshan geothermal belt are divided into four clusters by the self-organizing map. Cluster I, Cluster II, Cluster III, and Cluster IV represent the geothermal groundwater with the different degree of fluoride concentration pollution, the different hydrochemical type, and the physicochemical characteristic. The high F- concentration geothermal groundwater is characterized by HCO3-Na with alkalinity environment. The δD and δ18O values indicate that the geothermal groundwater origins from the atmospheric precipitation with the recharge elevation of 1000-2100 m. The dissolution of fluoride-bearing minerals is the main source of fluoride ions in geothermal water. Moreover, groundwater fluoride enrichment is also facilitated by water-rock interaction, cation exchange and alkaline environment. Additionally, the health risk assessment result reveals that the fluorine-enriched geothermal groundwater in the western part of Wugongshan area poses a more serious threat to human health than that of eastern part. The fluoride health risks of geothermal groundwater for different group show differentiation, 100% for children, 94.74% for adult females, and 68.42% for adult males, respectively. Compared with adult females and adult males, children faced the greatest health risks. The results of this study provide scientific evaluation for the utilization of geothermal groundwater and the protection of human health around the Wugongshan area.

Evaluation of potential human health risks arising from nitrate and fluoride in the groundwater of Aurangabad, Bihar using GIS and chemometric analysis.

This study employed the groundwater pollution index to assess the appropriateness of groundwater for human consumption. Additionally, the hazard index was utilized to evaluate the potential non-carcinogenic risks associated with fluoride and nitrate exposure among children, women, and men in the study region. A total of 103 samples were collected from the Aurangabad district of Bihar. The analyzed samples were assessed using several physicochemical parameters. Major cations in the groundwater are Ca2+ > Mg2+ and major anions are HCO3- > Cl- > SO42- > NO3- > F- > PO43-. Around 17% of the collected groundwater samples surpassed the allowable BIS concentration limits for Nitrate, while approximately 11% surpassed the allowed limits for fluoride concentration. Principal component analysis was utilized for its efficacy and efficiency in the analytical procedure. Four principal components were recovered that explained 69.06% of the total variance. The Hazard Quotient (HQ) of nitrate varies between 0.03-1.74, 0.02-1.47, and 0.03-1.99 for females, males, and children, respectively. The HQ of fluoride varies between 0.04-1.59, 0.04-1.34, and 0.05-1.82 for females, males, and children, respectively. The central part of the district was at high risk according to the spatial distribution maps of the total hazard index (THI). Noncarcinogenic risks due to THI are 47%, 37%, and 28% for children, females, and males, respectively. According to the human health risk assessment, children are more prone to getting affected by polluted water than adults. The groundwater pollution index (GPI) value ranges from 0.46 to 2.27 in the study area. Seventy-five percent of the samples fell under minor pollution and only one fell under high pollution. The spatial distribution of GPI in the research area shows that the central region is highly affected, which means that this water is unsuitable for drinking purposes.

Antibacterial and preventive effects of newly developed modified nano-chitosan/glass-ionomer restoration on simulated initial enamel caries lesions: An in vitro study.

BACKGROUND: Despite the superiority of glass-ionomer cements (GICs) over composites in treating white spot lesions (WSLs), there is still a concern about their preventive and antibacterial properties. Efforts have been made to improve the strength of their bond to demineralized enamel, fluoride release and antibacterial properties by adding nanoparticles of chitosan, which seems to be a promising method. OBJECTIVES: The aim of the present study was to assess the antibacterial effect, the microshear bond strength (µSBS) to enamel at the WSL area, and the fluoride and nano-chitosan release after modifying the polyacrylic acid liquid phase of a traditional GIC with different nano-chitosan volumes. MATERIAL AND METHODS: A total of 120 samples were prepared, and then divided into 4 groups (n = 30): G1 - non-modified GIC, which served as a control group, while G2, G3 and G4 were modified with different nano-chitosan volumes (50%, 100% and 150%, respectively). Microshear bond strength was assessed using a universal testing machine (UTM) after storage in distilled water for 24 h. Fluoride and nanochitosan release was measured with the use of spectrophotometers at different time points (initially, and at 1 h, 24 h, 48 h, 72 h, 1 week, 2 weeks, 3 weeks, and 6 weeks) after storage in distilled water. The antibacterial effect against the Streptococcus aureus strain was assessed with the agar diffusion test. The data was statistically analyzed. RESULTS: After 24-hour storage, G2 recorded a slight, yet non-significant, increase in the µSBS values (4.1 ±0.94 MPa) as compared to G1 (3.9 ±1.30 MPa). With regard to fluoride release, the amount recorded for G1 was significantly greater at the end of the 24-hour storage period (0.70 ±0.30 µmf/cm2) than modified nano-chitosan GIC groups; G1 was followed by G4 (0.54 ±0.34 µmf/cm2). The highest amount of nano-chitosan release after 24-hour storage was noted for G3 (0.85 ±0.00 µmf/cm2). The highest inhibition zone value was recorded for G2. CONCLUSIONS: Glass-ionomer cement modified with 50% nano-chitosan was shown to positively affect µSBS and the antibacterial effect, while modification with 150% nano-chitosan significantly increased fluoride release.

Effective removal and adsorption mechanism of fluoride from water by biochar-based Ce(III)-La(III)-crosslinked sodium alginate hybrid hydrogel.

An eco-friendly macroparticle biochar (BC)-based Ce(III)-La(III) crosslinked sodium alginate (SA) hybrid hydrogel (BC/Ce-SA-La) was synthesized by droplet polymerization and characterized by SEM-EDS, XRD, FTIR, UV-Vis and XPS. The effects of dosage, pH, contact time, temperature and coexisting ions on the F- ions removal by hybrid hydrogel, and the adsorption performance, interaction mechanism and reusability were investigated. The results demonstrate that the composite has a fancy wrinkle structure with a particle size of about 1.8 mm and abundant porosity on the surface. The removal rate of F- ions by BC/Ce-SA-La reached 90.2 % under the conditions of pH 2.0, 200 min of contact time and 298 K. The adsorption behavior was perfectly explained by Langmuir model, and the maximum adsorption capacity reached 129 mg/g. The adsorption process was an endothermic spontaneous reaction and followed Pseudo-second-order rate model. The strong adsorption was attributed to multi-interactions including complexation, hydrogen bonding and electrostatic adsorption between the composite and F- ions. Coexisting ions hardly interfered with the adsorption of F- ions by BC/Ce-SA-La except for a slight effect of phosphate. The composite after F- ion adsorption was easily separated and could be reused at least three times. BC/Ce-SA-La is a cost-effective and promising granular biosorbent.

Fluoride exposure during puberty induces testicular impairment via ER stress-triggered apoptosis in mice.

Fluoride, a ubiquitous environmental compound, carries significant health risks at excessive levels. This study investigated the reproductive toxicity of fluoride exposure during puberty in mice, focusing on its impact on testicular development, spermatogenesis, and underlying mechanisms. The results showed that fluoride exposure during puberty impaired testicular structure, induced germ cell apoptosis, and reduced sperm counts in mice. Additionally, the SOD activity and GSH content were significantly decreased, while MDA content was significantly elevated in the NaF group. Immunohistochemistry showed an increase in the number of cells positive for GRP78, a key ER stress marker. Moreover, qRT-PCR and Western blot analyses confirmed the upregulation of both Grp78 mRNA and protein expression, as well as increased mRNA expression of other ER stress-associated genes (Grp94, chop, Atf6, Atf4, and Xbp1) and enhanced protein expression of phosphorylated PERK, IRE1α, eIF2α, JNK, XBP-1, ATF-6α, ATF-4, and CHOP. In conclusion, our findings demonstrate that fluoride exposure during puberty impairs testicular structure, induces germ cell apoptosis, and reduces sperm counts in mice. ER stress may participate in testicular cell apoptosis, and contribute to the testicular damage and decreased sperm counts induced by fluoride.

Prediction of arsenic and fluoride in groundwater of the North China Plain using enhanced stacking ensemble learning.

Chronic exposure to elevated geogenic arsenic (As) and fluoride (F-) concentrations in groundwater poses a significant global health risk. In regions around the world where regular groundwater quality assessments are limited, the presence of harmful levels of As and F- in shallow groundwater extracted from specific wells remains uncertain. This study utilized an enhanced stacking ensemble learning model to predict the distributions of As and F- in shallow groundwater based on 4,393 available datasets of observed concentrations and forty relevant environmental factors. The enhanced model was obtained by fusing well-suited Extreme Gradient Boosting, Random Forest, and Support Vector Machine as the base learners and a structurally simple Linear Discriminant Analysis as the meta-learner. The model precisely captured the patchy distributions of groundwater As and F- with an AUC value of 0.836 and 0.853, respectively. The findings revealed that 9.0% of the study area was characterized by a high As risk in shallow groundwater, while 21.2% was at high F- risk identified as having a high risk of fluoride contamination. About 0.2% of the study area shows elevated levels of both of them. The affected populations are estimated at approximately 7.61 million, 34.1 million, and 0.2 million, respectively. Furthermore, sedimentary environment exerted the greatest influence on distribution of groundwater As, with human activities and climate following closely behind at 29.5%, 28.1%, and 21.9%, respectively. Likewise, sedimentary environment was the primary factor affecting groundwater F- distribution, followed by hydrogeology and soil physicochemical properties, contributing 27.8%, 24.0%, and 23.3%, respectively. This study contributed to the identification of health risks associated with shallow groundwater As and F-, and provided insights into evaluating health risks in regions with limited samples.

The thermoluminescence glow curves of LiF:Mg,Ti: characteristics and mechanisms.

The features of the glow curves of LiF:Mg,Ti are dependent on many parameters of irradiation, storage, ionisation density and readout. These are presented herein with emphasis on their complexity. Successful applications require some understanding of the great diversity of the glow curves. Glow curve analysis/deconvolution in order to better understand the mechanisms is a 'tricky business' even with Tm-Tstop analysis. In the theoretical framework of spatially correlated trapping and luminescent centres, a mechanism is described which simulates the behaviour of composite peak 5 at different cooling rates and following photon bleaching at 3.65 eV.

Effectiveness of nanosilver fluoride and silver diamine fluoride in arresting early childhood caries: a randomized controlled clinical trial.

BACKGROUND: One of the most prevalent health problems affecting children worldwide is untreated caries in primary teeth. Agents to arrest caries are used to manage untreated decay in children in disadvantaged communities. Nano Silver Fluoride (NSF) overcomes the staining problems of Silver Diamine Fluoride (SDF). This study compared the clinical cariostatic effect of NSF to 38% SDF for arresting caries lesions. METHODS: The study included 360 children younger than 4 years, with at least one active lesion, ICDAS score ≥ 3, recruited from nurseries in a rural area in Alexandria, Egypt, in 2022. They were randomly assigned to receive a single application of NSF at baseline, or two applications of SDF at baseline and after 6 months. The arrest of active carious lesions was assessed after 6 and 12 months using ICDAS criteria, and parents' satisfaction with child appearance was also assessed. Chi-Square test was used to compare the groups and multi-level multiple logistic regression was used to assess the effect of the intervention on caries arrest at lesion level and binary logistic regression was used to assess the effect at patient level. RESULTS: 1853 active lesions were included in children whose mean (SD) age was 42.3 (8.2) months. The arrest rate was significantly higher in the NSF than the SDF group at lesion level (78.4% and 65.0% at 6 months and 71.3% and 56.3% at 12 months, p < 0.001). In regression analysis, NSF had significantly higher odds of caries arrest than SDF at lesion level (at 6 months, AOR = 2.57, 95% CI: 1.55, 4.26 and at 12 month, AOR = 3.27, 95% CI: 1.89, 5.67). Parents of children receiving NSF had significantly greater satisfaction with their children's dental appearance than those receiving SDF: (97.2% and 76.1%, respectively, p < 0.001). CONCLUSION: NSF demonstrated greater effectiveness in arresting caries in preschool children without inducing black staining of teeth and with greater parental satisfaction than SDF. NSF can be an alternative to SDF in arresting caries especially in underprivileged communities. TRIAL REGISTRATION: The trial was registered in the clinicaltrials.gov registry (#NCT05255913)-16/02/2022.

Association between fluoride intake from drinking water and severity of dental fluorosis in Northern and Western Mexico: systematic review and meta-analysis.

BACKGROUND: Dental fluorosis (DF) is caused by excessive exposure to fluoride during odontogenesis and leads to various changes in the development of tooth enamel. Some regions in Mexico are considered endemic fluorosis zones due to the high fluoride content in drinking water. The objective of this study was to perform a systematic review and meta-analysis to identify the association between the concentration of fluoride in drinking water and the severity of dental fluorosis in northern and western Mexico. METHODS: This protocol was registered in the PROSPERO database (ID: CRD42023401519). The search for information was carried out in the PubMed/Medline, Scopus, SpringerLink, and Google Scholar databases between January 2015 and October 2023. The overall relative risk was calculated using the inverse of variance approach with the random effects method. The RoB 2.0 tool was used to construct risk plots. RESULTS: Eleven articles were analyzed qualitatively, and most of the included studies presented at least one level of DF severity; six articles were analyzed quantitatively, dividing them into two regions. In North region it was observed a higher prevalence of severe TF cases, corresponding to ≥ TF 5 category (4.78) [3.55, 6.42]. In the West region, most of the included studies presented a higher prevalence of less severe cases, corresponding to ≤ TF 4, in comparison with the North region (0.01) [0.00, 0.52], interpreted as a protective effect. CONCLUSION: The concentrations of fluorides in drinking water are reportedly high in these regions and are directly related to the severity of dental fluorosis experienced by the inhabitants. In the Northern region exists a major concentration of fluoride in drinking water compared with the Western region as well as a prevalence of higher severity cases of dental fluorosis.

Optimizing fertilizer usage for source reduction of salt and fluoride ion runoff discharge from a soda saline-alkali paddy field.

Planting rice is a beneficial strategy for improving soda saline-alkali soil, but it comes with the challenge of increased runoff discharge of salt and fluoride (F-) ions. The use of different nitrogen (N) fertilizers can impact this ion discharge, yet the specific characteristics of ion runoff under different N-fertilizer applications remain unclear. A field experiment was conducted in this study, applying five commonly used N-fertilizer types to monitor the ion runoff throughout an entire rice growing season. Salt ions and F- runoff discharge was significantly affected by N-fertilizer type, runoff event, and their interaction (p < 0.001). Regardless of N-fertilizer types, sodium (Na+) and bicarbonate (HCO3-) ions were consistently discharged from runoff in soda saline-alkali fields, constituting 20.55-25.06 % and 47.57-50.49 % of total ion discharges, respectively. Compared to no N-fertilizer (CK) and other N-fertilizer treatments, the organic-inorganic compound fertilizer (OCF) application significantly reduced Na+ and HCO3- runoff discharge, causing a decrease in the competitive adsorption capacity between HCO3- and F- (p < 0.05). The use of OCF and inorganic compound fertilizer (ICF) lowered pH in runoff water, resulting in reduced dissolution capacity of calcium fluoride in the soil and thereby decreasing total F- runoff discharge. In conclusion, OCF proves to be an effective N-fertilizer in mitigating salt ions and F- runoff discharge in soda saline-alkali paddy fields. Additionally, ICF demonstrates the ability to control F- runoff discharge.

Evaluation of setting kinetics, mechanical strength, ion release, and cytotoxicity of high-strength glass ionomer cement contained elastomeric micelles.

BACKGROUND: Low mechanical properties are the main limitation of glass ionomer cements (GICs). The incorporation of elastomeric micelles is expected to enhance the strength of GICs without detrimentally affecting their physical properties and biocompatibility. This study compared the chemical and mechanical properties, as well as the cytotoxicity, of elastomeric micelles-containing glass ionomer cement (DeltaFil, DT) with commonly used materials, including EQUIA Forte Fil (EF), Fuji IX GP Extra (F9), and Ketac Molar (KT). METHOD: Powder particles of GICs were examined with SEM-EDX. Setting kinetics were assessed using ATR-FTIR. Biaxial flexural strength/modulus and Vickers surface microhardness were measured after immersion in water for 24 h and 4 weeks. The release of F, Al, Sr, and P in water over 8 weeks was analyzed using a fluoride-specific electrode and ICP-OES. The toxicity of the material extract on mouse fibroblasts was also evaluated. RESULTS: High fluoride levels in the powder were detected with EF and F9. DT demonstrated an initial delay followed by a faster acid reaction compared to other cements, suggesting an improved snap set. DT also exhibited superior flexural strength than other materials at both 24 h and 4 weeks but lower surface microhardness (p < 0.05). EF and F9 showed higher release of F, Al, and P than DT and KT. There was no statistically significant difference in fibroblast viability among the tested materials (p > 0.05). CONCLUSIONS: Elastomeric micelles-containing glass ionomer cement (DT) exhibited satisfactory mechanical properties and cytocompatibility compared with other materials. DT could, therefore, potentially be considered an alternative high-strength GIC for load-bearing restorations.

Knowledge and practices of Iranian students (13-16 age) regarding the use of fluoride toothpaste.

INTRODUCTION: Fluoride is the main factor in reducing the prevalence of caries worldwide. However, there is insufficient knowledge about whether people in different age groups are aware of the benefits of fluoride toothpaste, as well as about people's daily oral care habits and whether they use fluoride. The purpose of this research is to investigate the knowledge and performance of Iranian students regarding the use of toothpaste containing fluoride. METHOD: This study was conducted on the first- and second-year high school students of Kerman city. Questionnaires containing personal questions, general questions, and questions related to students' knowledge and performance regarding the use of fluoride toothpaste were provided to them and then they were asked to complete and submit it. The results obtained from the survey were analyzed by T-test, Mann-Whitney test, and Chi-Square test in SPSS Version 24. The significance level in data analysis was P < 0.05. RESULTS: In this research, 681 forms including 252 boys and 429 girls were examined. The average age of the participants was 14.1 ± 0.4. 91.2% declared that they use toothpaste and 77.8% of them used toothpaste containing fluoride. 521 people stated that the price of toothpaste is important in using the type of toothpaste. 621 people used regular toothbrush and 609 people evaluated their oral health as good. 621 of the participants stated that toothpaste makes the mouth healthy. The average knowledge score was 16.7 ± 2.1 out of 24, which indicates the average knowledge of students in this field. CONCLUSION: This study showed that students' knowledge and performance about using fluoride-containing toothpaste is average. There was no significant relationship between performance and knowledge with age and gender. There was also a positive correlation between knowledge and performance indicating that increasing knowledge leads to an increase in behavioral changes. Also, there was a positive correlation between knowledge and performance, and a correlation coefficient of 0.731 was obtained between knowledge and performance. It shows that increasing knowledge leads to increasing behavioral changes.

In vitro effect of TiF4/NaF solution on the development of radiation-induced dentin caries.

OBJECTIVE: To evaluate the protective effect of an experimental solution containing TiF4/NaF on the development of radiation-induced dentin caries lesions. METHODOLOGY: bovine root samples were irradiated (70Gy) and distributed as following (n=12/group): Commercial Saliva (BioXtra), NaF (500 ppm F-), TiF4 (500 ppm F), TiF4/NaF (TiF4: 300 ppm F-, NaF: 190 ppm F-), and Phosphate buffer solution (PBS, negative control). Biofilm was produced using biofilm from irradiated patients and McBain saliva (0.2% of sucrose, at 37oC and 5% CO2) for five days. The treatments were applied 1x/day. Colony-forming units (CFU) were counted and demineralization was quantified by transversal microradiography. The ANOVA/Tukey test was applied for all parameters. RESULTS: All treatments reduced CFU for total microorganisms. TiF4 reduced Lactobacillus sp. (7.04±0.26 log10 CFU/mL) and mutans streptococci (7.18±0.28) CFU the most, when compared to PBS (7.58±0.21 and 7.75±0.17) and followed by NaF (7.12±0.31 and 7.34±0.22) and TiF4/NaF (7.16±0.35 and 7.29± 0.29). TiF4 and Commercial saliva showed the lowest integrated mineral loss (ΔZ-vol%.mm) (1977±150 and 2062±243, respectively) when compared to PBS (4540±335), followed by NaF (2403±235) and TiF4/NaF (2340±200). Commercial saliva was the only to significantly reduce mineral loss (LD-µm) (111±25) compared to PBS (153±24).Mean mineral loss (R-vol%) decreased by 35.2% for TiF4 (18.2±3.3) when compared to PBS (28.1±2.9) Conclusion: TiF4/NaF has a comparable anti-cariogenic effect to TiF4 and Commercial saliva under the model in this study.

Fluoride and children's IQ: evidence of causation lacking.

DATA SOURCES: Human, animal, and in vitro studies. Extensive literature search of multiple bibliographic databases, trial registries, major grey literature sources and bibliographies of identified studies. STUDY SELECTION: The authors aimed to identify studies which could be used to determine the maximum safe level for fluoride in drinking water. To identify new studies published since a 2016 Australian review, the search period was 2016 to July 2021. Studies which evaluated the association between either naturally or artificially fluoridated water (any concentration) and any health outcomes were included. No restrictions on study design or publication status. Articles published in a 'non-Latin language' were excluded. Screening of abstracts and full texts was in duplicate. For IQ and dental fluorosis, a top-up search was conducted between 2021 and Feb 2023. DATA EXTRACTION AND SYNTHESIS: Extensive data extraction. Risk of bias assessment using the OHAT tool. A narrative synthesis of the results was carried out. RESULTS: The review included 89 studies in humans, 199 in animals and 10 reviews of in vitro studies. Where there was consistent evidence of a positive association, in relation to a water fluoride concentration of <20 ppm (mg F/L), and where studies were judged to be acceptable or high quality, health effects were taken forwards for further examination of causality using Bradford Hill's 9 criteria. Of the 39 health outcomes reviewed, 4 were further assessed for causality. The authors reported 'strong' evidence of causality for dental fluorosis and reductions in children's IQ scores, 'moderate' strength evidence for thyroid dysfunction, 'weak' for kidney dysfunction, and 'limited' evidence for sex hormone disruption. CONCLUSIONS: The authors conclude that moderate dental fluorosis and reductions in children's IQ scores are the most appropriate health outcomes to use when setting an upper safe level of fluoride in drinking water. For reductions in children's IQ, the authors acknowledge a biological mechanism of action has not been elucidated, and the dose response curve is not clear at lower concentrations, limiting the ability to set an upper safe threshold.

Effect of training on bone quality in rats with insulin resistance induce by fluoride consumption.

When large amounts of Fluoride are consumed produces insulin resistance, but exercise can reverse insulin resistance in rats, because of a high fluoride uptake by bone tissue. However, bone quality has not been studied in those experiments. Therefore, the aim of this work was to evaluate bone quality in rats treated with fluoride when performing exercise. Sprague-Dawley rats were divided into 3 groups (n=6 per group): Control (drinking water without fluoride), Fluoride (drinking water with fluoride 15 mg/L for 30 days) and Exercise (daily running on a treadmill and drinking water with fluoride 15 mg/L for 30 days).  Then, bone mineral density, mechanical and histological properties and bone fluoride level were measured. No effect of treatment on any bone parameters were observed. These results indicate that exercise normalizes glucose metabolism in insulin-resistant rats by bone fluoride uptake; however, this increase in bone fluoride does not manifest in bone deterioration.

Cuando se consumen grandes cantidades de fluoruro se produce resistencia a la insulina, pero la realización de ejercicio puede revertir dicho efecto en ratas, debido a una alta absorción de fluoruro por el tejido óseo. Sin embargo, la calidad ósea no ha sido estudiada. Por ello, el objetivo de este trabajo fue evaluar la calidad ósea en ratas tratadas con flúor que realizan ejercicio. Se trabajó con ratas Sprague-Dawley que se dividieron en 3 grupos (n=6 por grupo): Control (recibiron agua sin flúor), Flúor (recibieron agua con flúor 15 mg/L durante 30 días) y Ejercicio (realizaron ejercicio diariamente en cinta ergométrica y recibieron agua con fluoruro 15 mg/L por 30 días). Luego, se midieron la densidad mineral ósea, las propiedades biomecánicas e histológicas y el nivel de fluoruro óseo. No se observó ningún efecto del tratamiento sobre ningún parámetro óseo. Estos resultados indican que el ejercicio normaliza el metabolismo de la glucosa en ratas resistentes a la insulina mediante la captación ósea de fluoruro; sin embargo, este aumento del fluoruro óseo no se manifiesta en deterioro óseo.

Hydro-meteorological aspects of soil fluorides in semi-arid soils using microwave remote sensing.

Soil fluoride is a critical determinant of soil fertility, human health and crop productivity. Soil fluoride can be increased by climatic conditions, irrigation water and anthropogenic activity, and it is important to control fluoride by understanding the complex relationships between atmospheric conditions and water systems. In this research, a detailed focus is on the hydrological and meteorological aspects of soil fluorides in semi-saturated and saturated soils to discuss the impact of irrigation, capillary rise and the combination of rainfall and anthropogenic activities such as fertilizer application on the soils in the dry spell and monsoon seasons of 2021 and 2022. A Sentinel-1 data can be used to estimate fluoride levels to the above soil conditions. In an effort to estimate fluoride levels in different hydro-meteorological scenarios, we have put forward a hypothesis that focuses on understanding the potential connections between hydro-meteorological factors (precipitation, groundwater levels, and temperature) and the levels of fluoride. The findings indicate that the extensive use of groundwater for irrigation leads to a rise in fluoride levels, posing a significant threat to crop health over time. Furthermore, the combined effects of irrigation and upheaval leaching on fluoride levels have shown strong statistical conformity (R2 > 0.85) with the relevant field-measured fluoride data for the year 2022. Importantly, areas affected by F upheaval are more sensitive to the sand and clay percentage in the soil because potential and dispersion behaviour enlarge the capillaries to decelerate the upward movement. A region-based discussion details the factors contributing to the increase of fluoride in soil helpful in taking remedial measures and mitigation plans.

Longitudinal study of the role of salivary proteins on radiation-related caries onset in head and neck cancer patients using 5000 ppm fluoride dentifrice up to one-year post-intensity modulated radiotherapy.

OBJECTIVES: Longitudinal assessment of the role of specific proteins on radiotherapy caries (RC) onset in head and neck cancer patients(HNC) up to one-year post-IMRT using a 5000ppm fluoride paste daily. MATERIALS AND METHODS: Dental status/salivary protein data were obtained from 40 HNC patients pre-IMRT, six months (T1) and 12 months (T2) post-IMRT (ethical approval/consent). DMFT/salivary parameters were quantified, including flow rate, mucin 5B/7, Immunoglobulin A (IgA), cystatin S and α-amylase. RESULTS: 45% patients had at least one carious lesion at T2, a significant reduction in the number of remaining teeth (65% <21), salivary flow rate (< 50%) and, protein secretion (< 0.05) post-IMRT. T1 IgA concentration/secretion rate was associated with RC (p < 0.05). Finally, IgA and total protein concentration obtained at T1 could provide a predictive pattern (AUC 82.3%) for the patients more predisposed to developing RC at T2. CONCLUSIONS: This study demonstrated the significant association of RC with salivary proteins in HNC patients treated with IMRT, revealing the potential role of salivary proteins in the early diagnosis of RC. CLINICAL RELEVANCE: This research contributes to revealing salivary proteins association with RC, and its role in early diagnosis. Therefore, this could be the first step towards personalized medicine approaches to improve this group quality-of-life.

Effectiveness of risk-based caries management among Chinese preschool children: a randomized controlled single-blind trial.

BACKGROUND: Early childhood caries (ECC) remain a serious oral health problem on a global scale. Risk-based caries management (RBCM) implemented in some parts of the world has been effective in preventing ECC. However, there is a lack of prospective research on the application of RBCM among Chinese children, and little is known about its effectiveness. The purpose of this study was to evaluate the effectiveness of RBCM in preventing caries among children aged 3-5 years in Wanzhou District, Chongqing Municipality, China. METHODS: Three- to five-year-old children from four kindergartens in Wanzhou were randomly selected for baseline dental examination and caries risk assessment (CRA) and randomly assigned to the experimental group (EG) or the control group (CG) according to the kindergarten. The EG received caries prevention measures of different intensities based on the child's caries risk level. The CG received full-mouth fluoride twice a year according to standard prevention, regardless of their caries risk. One year later, another dental examination and CRA were conducted, to observe changes in the decayed, missing, and filled teeth (dmft) index and caries risk, and to analyze potential factors that may affect the incidence of new caries. RESULTS: Complete data were collected from 291 children (EG, N = 140, 84.8%; CG, N = 181, 83.4%). A total of 25.7% of the EG and 50.3% of the CG children developed new caries, with newly added dmft scores of 0.54 ± 1.12 and 1.32 ± 1.72, respectively (P < 0.05). Multivariate logistic regression indicated that children living in rural areas, assigned to the CG, and rated as high-risk at baseline were more likely to develop new caries (P < 0.05). The proportion of children with an increased caries risk in the EG was significantly lower than that in the CG (P < 0.05). CONCLUSIONS: RBCM effectively prevented new caries in 3- to 5-year-old Wanzhou children and reduced the proportion of children at increased risk of caries. It is an effective approach for preventing ECC. CLINICAL TRIAL REGISTRATION: This trial was registered in the Chinese Clinical Trials Register. The registration number was ChiCTR230067551 (11/01/2023).