Effects of surface fluoride modification on TiO2 for the photocatalytic oxidation of toluene.

In the present study, we investigated the influence of surface fluorine (F) on TiO2 for the photocatalytic oxidation (PCO) of toluene. TiO2 modified with different F content was prepared and tested. It was found that with the increasing of F content, the toluene conversion rate first increased and then decreased. However, CO2 mineralization efficiency showed the opposite trend. Based on the characterizations, we revealed that F substitutes the surface hydroxyl of TiO2 to form the structure of Ti-F. The presence of the appropriate amount of surface Ti-F on TiO2 greatly enhanced the separation of photogenerated carriers, which facilitated the generation of ·OH and promoted the activity for the PCO of toluene. It was further revealed that the increase of only ·OH promoted the conversion of toluene to ring-containing intermediates, causing the accumulation of intermediates and then conversely inhibited the ·OH generation, which led to the decrease of the CO2 mineralization efficiency. The above results could provide guidance for the rational design of photocatalysts for toluene oxidation.

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.

Fluoride removal from coal mining water using novel polymeric aluminum modified activated carbon prepared through mechanochemical process.

Defluoridation of coal mining water is of great significance for sustainable development of coal industry in western China. A novel one-step mechanochemical method was developed to prepare polymeric aluminum modified powder activated carbon (PAC) for effective fluoride removal from coal mining water. Aluminum was stably loaded on the PAC through facile solid-phase reaction between polymeric aluminum (polyaluminum chloride (PACl) or polyaluminum ferric chloride (PAFC)) and PAC (1:15 W/W). Fluoride adsorption on PACl and PAFC modified PAC (C-PACl and C-PAFC) all reached equilibrium within 5 min, at rate of 2.56 g mg-1 sec-1 and 1.31 g mg-1 sec-1 respectively. Larger increase of binding energy of Al on C-PACl (AlF bond: 76.64 eV and AlFOH bond: 77.70 eV) relative to that of Al on C-PAFC (AlF bond: 76.52 eV) explained higher fluoride uptake capacity of C-PACl. Less chloride was released from C-PACl than that from C-PAFC due to its higher proportion of covalent chlorine and lower proportion of ionic chlorine. The elements mapping and atomic composition proved the stability of Al loaded on the PAC as well as the enrichment of fluoride on both C-PACl and C-PAFC. The Bader charge, formation energy and bond length obtained from DFT computational results explained the fluoride adsorption mechanism further. The carbon emission was 7.73 kg CO2-eq/kg adsorbent prepared through mechanochemical process, which was as low as 1:82.3 to 1:8.07 × 104 compared with the ones prepared by conventional hydrothermal methods.

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.

[Damage and changes in expression of autophagy related factors LC3 and p62 of condylar cartilage in fluorosis mouse].

PURPOSE: To study the damage and the expression of LC3 and p62 of condylar cartilage in fluorosis mouse. METHODS: Thirty 4-week-old male C57BL/6 mice were randomly divided into control group and the experimental group with 15 animals in each group. The control group received regular drinking water and the experimental group received a fluoride concentration of 75 mg/L drinking water for 8 weeks. The structure of condylar cartilage was observed through modified safranine O-fast green FCF cartilage stain kit. Immunohistochemistry was used to detect the expression of MMP-13, type Ⅱ collagen and LC3 and p62. Two-way analysis of variance test was conducted for analysis of semi-quantitative results of immunohistochemistry using SPSS 22.0 software package. RESULTS: Compared with the control group, the fibrocartilage layer of the experimental group became thinner, the condrocytes were smaller, and the staining became deeper.Immunohistochemistry results showed that the expression of MMP-13 and LC3 increased; the expression of type Ⅱ collagen and p62 decreased in the experimental group. CONCLUSIONS: There was degeneration of the condylar cartilage and autophagy in mice with drinking water containing 75 mg/L fluoride.

Efficient recovery of highly pure CaF2 from fluorine-containing wastewater using an icy lime solution.

Developing a feasible and low-cost strategy for the recovery of calcium fluoride efficiently from fluoride-containing wastewater is very essential for the recycle of fluoride resources. Herein, a modified lime precipitation method was employed to recover CaF2 from fluorinated wastewater using a special icy lime solution. Intriguingly, the highest F- removal was greater than 95% under the optimal condition, leaving a fluoride concentration from 200 to 8.64 mg/L, while the lime dosage was much lower than that of industry. Importantly, spherical-shaped CaF2 particles with a 93.47% purity and size smaller than 600 nm were recovered, which has a high potential for the production of hydrofluoric acid. Besides, the precipitation was significantly affected by Ca/F molar ratio, stirring time, temperature, and solution pH. Furthermore, the thermodynamics and kinetics were investigated in detail to reveal the crystallization process. As a result, the defluorination reaction followed the pseudo-second order reaction kinetics model. Also, CO2 in the air adversely influenced the CaF2 purity. Based on this facile method, a high lime utilization efficiency was applied to defluorination, which contributed to protecting the environment and saving costs. This study, therefore, provides a feasible approach for the green recovery of fluorine resources and has significance for related research.

Fluoride-induced hypertension by regulating RhoA/ROCK pathway and phenotypic transformation of vascular smooth muscle cells: In vitro and in vivo evidence.

Fluoride exposure has been implicated as a potential risk factor for hypertension, but the underlying mechanisms remain unclear. This study investigated the role of the RhoA/ROCK signaling pathway in fluoride-induced hypertension. Male Wistar rats were divided into different groups and exposed to varying concentrations of sodium fluoride (NaF) or sodium chloride (NaCl) via drinking water. The rats' blood pressure was measured, and their aortic tissue was utilized for high-throughput sequencing analysis. Additionally, rat and A7r5 cell models were established using NaF and/or Fasudil. The study evaluated the effects of fluoride exposure on blood pressure, pathological changes in the aorta, as well as the protein/mRNA expression levels of phenotypic transformation indicators (a-SMA, calp, OPN) in vascular smooth muscle cells (VSMCs), along with the RhoA/ROCK signaling pathway (RhoA, ROCK1, ROCK2, MLC/p-MLC). The results demonstrated that fluoride exposure in rats led to increased blood pressure. High-throughput sequencing analysis revealed differential gene expression associated with vascular smooth muscle contraction, with the RhoA/ROCK signaling pathway emerging as a key regulator. Pathological changes in the rat aorta, such as elastic membrane rupture and collagen fiber deposition, were observed following NaF exposure. However, fasudil, a ROCK inhibitor, mitigated these pathological changes. Both in vitro and in vivo models confirmed the activation of the RhoA/ROCK signaling pathway and the phenotypic transformation of VSMCs from a contractile to a synthetic state upon fluoride exposure. Fasudil effectively inhibited the activities of ROCK1 and ROCK2 and attenuated the phenotypic transformation of VSMCs. In conclusion, fluoride has the potential to induce hypertension through the activation of the RhoA/ROCK signaling pathway and phenotypic changes in vascular smooth muscle cells. These results provide new insights into the mechanism of fluoride-induced hypertension.

Severe magnitude of dental and skeletal fluorosis and its impact on society and environment in a part of Manbhum-Singhbhum Plateau, India.

BACKGROUND: Numerous approaches have been adopted to evaluate limited freshwater resources and the associated health hazards due to excessive amounts of fluoride in drinking water. The study aims to assess the degree and severity of dental and skeletal fluorosis and examine the broader effects of fluorosis on human health and society in the Manbhum-Singhbhum Plateau region, India. METHODS: The Community Fluorosis Index (CFI) and Dean's Index have been used to measure the magnitude and severity of dental and skeletal fluorosis. Questionnaire surveys, Focus Group Discussions (FGDs), and appropriate statistical methods have been applied to identify the social impacts. Risk-prone zones have been identified through overlay analysis using geoinformatics. RESULTS: About 54.60% of people in 67 villages of this part of the Manbhum-Singhbhum Plateau are affected in varying degrees of fluorosis ranging from very mild to mild, moderate, and severe dental fluorosis. Among these 67 villages, Janra (Manbazar I) and Hijla (Barabazar) have the most severely affected people. School dropout (n = 426), social isolation (n = 149), remarriage (n = 21), and physically disabled (n = 75) have also been reported. The study shows that about 414.29 km2 of the Manbhum-Singhbhum Plateau comes under the high-risk-prone category. CONCLUSIONS: The societal and environmental awareness of the fluorosis-affected individuals is almost absent in this region. Economic hardships, lack of education, inadequate health care facilities, water scarcity, and lack of awareness increase the magnitude of health hazards and societal vulnerability of the people in this region, who are largely dependent on natural resources.

Fluoride-related changes in the fetal cord blood proteome; a pilot study.

BACKGROUND: Fluoride exposure during pregnancy has been associated with various effects on offspring, including changes in behavior and IQ. To provide clues to possible mechanisms by which fluoride may affect human fetal development, we completed proteomic analyses of cord blood serum collected from second-trimester pregnant women residing in northern California, USA. OBJECTIVE: To identify changes in cord blood proteins associated with maternal serum fluoride concentration in pregnant women. METHODS: The proteomes of 19 archived second-trimester cord blood samples from women living in northern California, USA, and having varied serum fluoride concentrations, were analyzed by quantitative mass spectrometry. The 327 proteins that were quantified were characterized by their abundance relative to maternal serum fluoride concentration, and subjected to pathway analyses using PANTHER and Ingenuity Pathway Analysis processes. RESULTS: Pathway analyses showed significant increases in process related to reactive oxygen species and cellular oxidant detoxification, associated with increasing maternal serum fluoride concentrations. Pathways showing significant decreases included complement cascade, suggesting alterations in alterations in process associated with inflammation. CONCLUSION: Maternal fluoride exposure, as measured by serum fluoride concentrations in a small, but representative sample of women from northern California, USA, showed significant changes in the second trimester cord blood proteome relative to maternal serum fluoride concentration.

[Development of the capacity to communicate risks related to childhood exposure to fluorides through an online educational strategy]. / Desarrollo de la capacidad de comunicar riesgos relacionados con la exposición infantil a fluoruros, a través de una estrategia educativa en línea.

Fluorides are contaminants that occur frequently and, generally, naturally in groundwater, affecting countries that depend on these waters for irrigation and human consumption. Chronic exposure to fluorides generates various health effects; therefore, this research was based on education and risk communication to contribute to the resolution of the problem of fluoride exposure in the population. The objective was to develop the capacity to design risk communication programs for personnel involved in the response and management of environmental health risks, with emphasis on fluoride exposure. An online pilot training course on risk communication and fluoride exposure was designed and implemented. For the analysis of the risk perception and knowledge of the participants, before and after the course, a questionnaire was applied and a focus group was conducted. In addition, the participants carried out a series of activities and designed a risk communication program to assess the degree to which the capacity to develop risk communication programs was achieved. To improve the pilot course, two satisfaction surveys were designed and implemented, and a SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis was conducted. The results showed an increase in the level of knowledge and changes in the participants' perception; regarding the ability to design risk communication programs, two participants were able to design them excellently. Previous experience, motivation, commitment to learn and the feedback provided during the course influenced the development of this ability.

Los fluoruros son contaminantes presentes con frecuencia y generalmente de forma natural en aguas subterráneas, y afectan a países que dependen de estas aguas para el riego y el consumo humano. La exposición crónica a fluoruros genera diversos efectos a la salud; por lo anterior, esta investigación se basó en la educación y la comunicación de riesgos para contribuir a la resolución del problema de exposición a fluoruros en la población. El objetivo fue desarrollar la capacidad de diseñar programas de comunicación de riesgos del personal involucrado en la respuesta y manejo de los riesgos ambientales para la salud, con énfasis en la exposición a fluoruros. Se diseñó e implementó un curso piloto de formación en línea sobre comunicación de riesgos y exposición a fluoruros. Para el análisis de la percepción de riesgos y conocimientos de los participantes, antes y después del curso, se aplicó un cuestionario y se llevó a cabo un grupo focal. Además, los asistentes realizaron una serie de actividades y diseñaron un programa de comunicación de riesgos con el que se valoró el grado en que se alcanzó la capacidad de desarrollar programas de comunicación de riesgos. Para mejorar el curso piloto se diseñaron y aplicaron dos encuestas de satisfacción y se realizó un análisis FODA (Fortalezas, Oportunidades, Debilidades, Amenazas). Los resultados mostraron un incremento en el nivel de conocimientos y cambios en la percepción de los participantes; en cuanto a la capacidad de diseñar programas de comunicación de riesgos, dos participantes lograron diseñarlo de manera excelente. La experiencia previa, la motivación, el compromiso para aprender y la retroalimentación brindada durante el curso, influyeron en el desarrollo de esta capacidad.

Os fluoretos são contaminantes que ocorrem com frequência e, geralmente, de forma natural nas águas subterrâneas, afetando os países que dependem dessas águas para irrigação e consumo humano. A exposição crônica aos fluoretos gera vários efeitos à saúde; portanto, esta pesquisa baseou-se na educação e na comunicação de riscos para contribuir com a solução do problema da exposição ao fluoreto na população. O objetivo foi desenvolver a capacidade de elaborar programas de comunicação de risco para o pessoal envolvido na resposta e no gerenciamento de riscos ambientais à saúde, com ênfase na exposição à fluoretos. Foi elaborado e implementado um curso piloto de treinamento online sobre comunicação de riscos e exposição. Para a análise da percepção de risco e do conhecimento dos participantes antes e depois do curso, foi aplicado um questionário e aplicado um grupo de foco. Além disso, os participantes realizaram uma série de atividades e elaboraram um programa de comunicação de riscos para avaliar até que ponto a capacidade de desenvolver programas de comunicação de riscos foi alcançada. Para aprimorar o curso piloto, foram duas pesquisas de satisfação foram desenvolvidas e implementadas e uma análise FOFA (Forças, Oportunidades, Fraquezas e Ameaças) foi aplicada. Os resultados mostraram um aumento no nível de conhecimento e mudanças nas percepções dos participantes; em termos da capacidade de elaborar programas de comunicação de riscos, dois participantes conseguiram elaborar excelentes programas de comunicação de riscos. A experiência prévia, a motivação, o compromisso com o aprendizado e o feedback fornecido durante o curso influenciaram o desenvolvimento dessa capacidade.

Theobromine for Remineralization of White Spot Lesions on Dental Enamel: A Systematic Review and Meta-analysis.

AIM: This systematic review and meta-analysis evaluated theobromine's (Theobroma cacao) potential in remineralizing white spot lesions in dental enamel. Methods: This study is reported according to the PRISMA checklist and was registered in PROSPERO (CRD42023414371). In vitro tests that evaluated the remineralizing potential of theobromine compared to fluoride ion after demineralization for the formation of white spot lesions on enamel were selected, with no limitation on the year of publication. Electronic searches were performed in PubMed/MEDLINE, Scopus, and Web of Science by two independent researchers. Thirty articles were received of which six were selected according to the inclusion criteria. RESULTS: The selected studies evaluated the Enamel Surface Microhardness (SMH), Vickers or Knoop, before and after treatment with theobromine and fluoride solutions. For the SMH Vickers, there were no differences between groups at baseline (p=1.00; mean difference: -0.00; CI: -11.36 to 11.36) and after treatment (p=0.51; mean difference: 4.12; CI: -8.16 to 16.41). The results of SMH Knoop showed differences between groups at baseline, favoring the experimental group (p=0.002; mean difference: 9.84; CI: 3.65 to 16.02) and after treatment favoring the control group (p=0.00001; mean difference: -5.45; CI: -7.62 to -3.27). CONCLUSION: The use of theobromine increases the microhardness of dental enamel subjected to a demineralization process, thus being effective in the remineralization of this tissue with success equivalent to that obtained with the use of fluoride.

Magnetic lanthanide sensor with self-ratiometric time-resolved luminescence for accurate detection of epithelial cancerous exosomes.

Fluorescence-based LB (liquid biopsy) offers a rapid means of detecting cancer non-invasively. However, the widespread issue of sample loss during purification steps will diminish the accuracy of detection results. Therefore, in this study, we introduce a magnetic lanthanide sensor (MLS) designed for sensitive detection of the characteristic protein, epithelial cell adhesion molecule (EpCAM), on epithelial tumor exosomes. By leveraging the inherent multi-peak emission and time-resolved properties of the sole-component lanthanide element, combined with the self-ratiometric strategy, MLS can overcome limitations imposed by manual operation and/or sample complexity, thereby providing more stable and reliable output results. Specifically, terbium-doped NaYF4 nanoparticles (NaYF4:Tb) and deformable aptamers terminated with BHQ1 were sequentially introduced onto superparamagnetic silica-decorated Fe3O4 nanoparticles. Prior to target binding, emission from NaYF4:Tb at 543 nm was partially quenched due to the fluorescence resonance energy transfer (FRET) from NaYF4:Tb to BHQ1. Upon target binding, changes in the secondary structure of aptamers led to the fluorescence intensity increasing since the deconfinement of distance-dependent FRET effect. The characteristic emission of NaYF4:Tb at 543 nm was then utilized as the detection signal (I1), while the less changed emission at 583 nm served as the reference signal (I2), further reporting the self-ratiometric values of I1 and I2 (I1/I2) to illustrate the epithelial cancerous features of exosomes while ignoring possible sample loss. Consequently, over a wide range of exosome concentrations (2.28 × 102-2.28 × 108 particles per mL), the I1/I2 ratio exhibited a linear increase with exosome concentration [Y(I1/I2) = 0.166 lg (Nexosomes) + 3.0269, R2 = 0.9915], achieving a theoretical detection limit as low as 24 particles per mL. Additionally, MLS effectively distinguished epithelial cancer samples from healthy samples, showcasing significant potential for clinical diagnosis.

Electron bifurcation and fluoride efflux systems implicated in defluorination of perfluorinated unsaturated carboxylic acids by Acetobacterium spp.

Enzymatic cleavage of C─F bonds in per- and polyfluoroalkyl substances (PFAS) is largely unknown but avidly sought to promote systems biology for PFAS bioremediation. Here, we report the reductive defluorination of α, ß-unsaturated per- and polyfluorocarboxylic acids by Acetobacterium spp. The microbial defluorination products were structurally confirmed and showed regiospecificity and stereospecificity, consistent with their formation by enzymatic reactions. A comparison of defluorination activities among several Acetobacterium species indicated that a functional fluoride exporter was required for the detoxification of the released fluoride. Results from both in vivo inhibition tests and in silico enzyme modeling suggested the involvement of enzymes of the flavin-based electron-bifurcating caffeate reduction pathway [caffeoyl-CoA reductase (CarABCDE)] in the reductive defluorination. This is a report on specific microorganisms carrying out enzymatic reductive defluorination of PFAS, which could be linked to electron-bifurcating reductases that are environmentally widespread.

Colloidal chitosan-silver nanoparticles-fluoride nanocomposite as an antibacterial mouthwash against salivary Streptococcus mutans in orthodontic patients (a randomized clinical trial).

OBJECTIVES: This study aimed to synthesize and characterize colloidal chitosan-silver nanoparticles-fluoride nanocomposite (CCAgNPF) and evaluate its efficacy compared to chlorhexidine on salivary Streptococcus mutans in orthodontic patients. MATERIALS AND METHODS: AgNPs stabilized with chitosan were synthesized by chemical reduction of AgNO3. The nanoparticles were characterized with SEM, FTIR, DLS and ICP-OES. The MIC and MBC against S. mutans and IC50 concentration of CCAgNPF were obtained for antibacterial and cytotoxicity evaluations, respectively. For the clinical study, a total of 45 orthodontic patients were divided into three groups of 15 and used the following mouthwashes twice a day for 1 month: CCAgNPF, chlorhexidine 0.2% and the combination of these mouthwashes. The colony count of salivary S. mutans was evaluated before and after using the mouthwashes. The data were analyzed using One-way ANOVA and Tukey's test. RESULTS: Stabilized AgNPs were spherical with a diameter of 25.3 ± 3.3 nm. The MIC, MBC and IC50 of CCAgNPF were 4.42, 8.85 and 18.89 µg/ml. All mouthwashes reduced the salivary S. mutans of the orthodontic patients, however, no significant difference was found between the efficacy of CCAgNPF and chlorhexidine (P-value > 0.05). The best results were achieved by the combination of CCAgNPF and chlorhexidine mouthwashes (P-value < 0.05). CONCLUSION: The CCAgNPF and its combination with chlorhexidine present potent bactericidal, biocompatible and effective anti-carious mouthwashes for orthodontic patients. CLINICAL RELEVANCE: This study proved CCAgNPF as an antibacterial mouthwash with lower cytotoxicity and side effects for patients undergoing orthodontic treatments to maintain oral hygiene and reduce salivary S. mutans.

The damage and remineralization strategies of dental hard tissues following radiotherapy.

OBJECTIVES: This study pursued two main purposes. The first aim was to expound on the microscopic factors of radiation-related caries (RRC). Further, it aimed to compare the remineralization effect of different remineralizing agents on demineralized teeth after radiotherapy. METHODS: The enamel and dentin samples of bovine teeth were irradiated with different doses of radiation. After analysis of scanning electron microscope (SEM), X-Ray diffraction (XRD), and energy dispersive spectrometer (EDS), the samples irradiated with 50 Gy radiation were selected and divided into the demineralization group, the double distilled water (DDW) group, the Sodium fluoride (NaF) group, the Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) group, the NaF + CPP-ACP group, and the Titanium tetrafluoride (TiF4) group. After demineralization, remineralizing agents treatment, and remineralization, the samples were evaluated using SEM, atomic force microscope (AFM), EDS, and transverse microradiography (TMR). RESULTS: A radiation dose of 30 Gy was sufficient to cause damage to the dentinal tubules, but 70 Gy radiation had little effect on the microstructure of enamel. Additionally, the NaF + CPP-ACP group and the TiF4 group significantly promoted deposit formation, decreased surface roughness, and reduced mineral loss and lesion depth of demineralized enamel and dentin samples after radiation. CONCLUSIONS: Radiation causes more significant damage to dentin compared to enamel. NaF + CPP-ACP and TiF4 had a promising ability to promote remineralization of irradiated dental hard tissues. ADVANCES IN KNOWLEDGE: This in vitro study contributes to determining a safer radiation dose range for teeth and identifying the most effective remineralization approach for RRC.

Antibacterial and oral tissue effectiveness of a mouthwash with a novel active system of amine + zinc lactate + fluoride.

OBJECTIVES: Reflecting the need for an effective support for the daily oral hygiene routine of patients experiencing (symptoms of) gum inflammation, a new mouthwash has been developed containing an amine + zinc lactate + fluoride system. The in vitro efficacy of this product was assessed using traditional laboratory methods, as well as novel experimentation. MATERIALS AND METHODS: This mouthwash has been evaluated in a series of laboratory tests including two short interval kill tests (SIKTs), a 12-h (longer term) biofilm regrowth assay, a plaque glycolysis assay, and an aerobic, repeated exposure biofilm model, as well as tests for soft tissue uptake and LPS neutralization. RESULTS: Several laboratory studies demonstrate that a mouthwash containing an amine + zinc lactate + fluoride system provides short-term and long-term antibacterial activity. While the immediate efficacy of this formula has been shown to be driven by the presence of the amine, zinc lactate provides a long-term antibacterial effect, as well as is able to inhibit bacterial metabolism. CONCLUSIONS: This research provides the basis for understanding the mode of action of this new mouthwash formulation and explains the previously observed clinical efficacy of this formula against plaque and gingivitis.

A cross-sectional study of physicians on fluoride-related beliefs and practices, and experiences with fluoride-hesitant caregivers.

The goal of this study was to describe medical providers' fluoride-related beliefs and practices, experiences with fluoride-hesitant caregivers, and barriers to incorporating oral health activities into their practice. In this cross-sectional study, we specifically tested the hypothesis of whether these factors differed between pediatric and family medicine providers. A 39-item online survey was administered to a convenience sample of pediatric and family medicine providers in Washington state and Ohio (U.S.A.). Responses to the fluoride survey were compared between pediatric and family medicine providers with a chi-square test (α = 0.05). Of the 354 study participants, 45% were pediatric providers and 55% were family medicine providers. About 61.9% of providers believed fluoridated water was highly effective at preventing tooth decay while only 29.1% believed prescription fluoride supplements were highly effective. Nearly all providers recommend over-the-counter fluoride toothpaste (87.3%), 44.1% apply topical fluoride in clinic, and 30.8% prescribe fluoride supplements. Most providers reported fluoride hesitancy was a small problem or not a problem (82.5%) and the most common concerns patients raise about fluoride were similar to those raised about vaccines. Lack of time was the most commonly reported barrier to incorporating oral health into practice, which was more commonly reported by family medicine providers than pediatric providers (65.6% vs. 50.3%; p = .005). Pediatric and family medicine providers have early and frequent access to children before children visit a dentist. Improving the use of fluorides through children's medical visits could improve pediatric oral health and reduce oral health inequities, especially for vulnerable populations at increased risk for tooth decay.

Optical properties investigation and multicolor behavior of neodymium (Nd3+)-doped oxyfluoride silicate glasses SiO2-PbO-PbF2.

The aim of this research is to investigate novel compositions of oxyfluoride glasses doped with Neodymium (Nd3+) rare earth ions in the visible spectrum. This area has not been extensively studied in the existing literature, so it is vital to understand the favorable photoluminescence characteristics within this part of the electromagnetic spectrum. Therefore, we synthesized and characterized SiO2-PbO-PbF2 (SPF) doped with 1% neodymium (Nd3+) ions glasses. Spectroscopic analyses, based on Judd-Ofelt theory, were conducted on absorption spectra. These analyses enabled to determine absorption cross-sections, transition probabilities, and Judd-Ofelt intensity parameters Ω2, Ω4, and Ω6 for the different transition. Additionally, we calculated various radiative properties, such as branching ratios, integrated cross-sections, radiative lifetimes, emission cross-section, optical gain, and the multicolor behavior (chromaticity coordinates, CIE diagram) under different excitation wavelengths. The results suggest promising prospects for using these oxyfluoride silicate glasses doped with Nd3+ as a fluorophore, potentially for lasing materials around 630-nm emission and in other photonic applications.

Stepwise extraction of lithium and potassium and recovery of fluoride from aluminum electrolyte wastes through calcification roasting-two-stage leaching.

Aluminum electrolyte is a necessity for aluminum reduction cells; however, its stock is rising every year due to several factors, resulting in the accumulation of solid waste. Currently, it has become a favorable material for the resources of lithium, potassium, and fluoride. In this study, the calcification roasting-two-stage leaching process was introduced to extract lithium and potassium separately from aluminum electrolyte wastes, and the fluoride in the form of CaF2 was recycled. The separation behaviors of lithium and potassium under different conditions were investigated systematically. XRD and SEM-EDS were used to elucidate the phase evolution of the whole process. During calcification roasting-water leaching, the extraction efficiency of potassium was 98.7% under the most suitable roasting parameters, at which the lithium extraction efficiency was 6.6%. The mechanism analysis indicates that CaO combines with fluoride to form CaF2, while Li-containing and K-containing fluorides were transformed into water-insoluble LiAlO2 phase and water-soluble KAlO2 phase, respectively, thereby achieving the separation of two elements by water leaching. In the second acid-leaching stage, the extraction efficiency of lithium was 98.8% from water-leached residue under the most suitable leaching conditions, and CaF2 was obtained with a purity of 98.1%. The present process can provide an environmentally friendly and promising method to recycle aluminum electrolyte wastes and achieve resource utilization.

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.