Health risk assessment in an area of dental fluorosis disease from high fluoride drinking water: a case study from southeastern Türkiye

This study focuses on identifying fluoride (F‒) concentrations and its health risk assessment (HRA) in drinking water sources in south-eastern Türkiye. Groundwater quality was assessed using some graphical approaches such as Schoeller and Piper diagrams and GIS mapping. Average daily exposure dosages through oral and dermal contact exposure routes were considered to determine the potential health risk of F‒ in groundwater. Groundwater samples were taken from 53 points in spring, summer, autumn, and winter seasons. The results showed that the average annual F‒ concentrations in water resources in the study area were 0.26‒3.62 mg/L. According to the HRA results, the highest F‒ health risk in this region was observed in children, followed by teenagers and adults. This study indicated that there is a strong relationship between the high health risk (4.28 > 3.5) in children and dental fluorosis caused by high F‒ concentration in groundwater.

Tooth whitening: current status and prospects

As a safe, effective, economical, and convenient technique, tooth whitening is one of the most popular treatments for improving tooth discoloration. This review summarizes the theoretical and recent research developments in the classification and mechanisms of tooth discoloration, as well as the principles, agents, effects, and side effects of tooth whitening techniques. The aim is to provide a basis for the clinical treatment of tooth whitening techniques and to suggest possible new ideas for further research. The accepted mechanism of whitening is the redox reaction of oxides in the whitening reagent, and the whitening effect is remarkable. However, side effects such as tooth sensitivity and irritation of gum and other oral soft tissues can still occur. It is recommended that more monitoring be carried out in the clinic to monitor these side effects, and care should be taken to protect the soft tissues in the mouth during office whitening procedures. Furthermore, there is a need to develop new additives or natural whitening products to reduce the occurrence of side effects.

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

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

ERS Mediated by GRP-78/PERK/CHOP Signaling Is Involved in Fluoride-Induced Ameloblast Apoptosis

Fluoride can be widely ingested from the environment, and its excessive intake could result in adverse effects. Dental fluorosis is an early sign of fluoride toxicity which can cause esthetic and functional problems. Though apoptosis in ameloblasts is one of the potential mechanisms, the specific signal cascade is in-conclusive. High-throughput sequencing and molecular biological techniques were used in this study to explore the underlying pathogenesis of dental fluorosis, for its prevention and treatment. A fluorosis cell model was established. Viability and apoptosis rate of mouse ameloblast-derived cell line (LS8 cells) was measured using cell counting kit-8 (CCK-8) assay and flow cytometry analysis. Cells were harvested with or without 2-mM sodium fluoride (NaF) stimulation for high-throughput sequencing. Based on the sequencing data, subcellular structures, endoplasmic reticulum stress (ERS), and apoptosis related biomarkers were verified using transmission electron microscopy, quantitative real-time polymerase chain reaction, and Western blotting techniques. Expression of ERS markers, apoptosis related proteins, and enamel formation enzymes were detected using Western blotting after addition of 4-phenylbutyrate (4-PBA). NaF-inhibited LS8 cells displayed time- and dose- dependent viability. Additionally, apoptosis and morphological changes were observed. RNA-sequencing data showed that protein processing in endoplasmic reticulum was obviously affected. ERS and apoptosis were induced by excessive NaF. Downregulation of kallikrein-related peptidase 4 (KLK4) was also observed. Inhibition of ERS by 4-PBA rescued the apoptotic and functional protein changes in cells. Excessive fluoride induces apoptosis by activating ERS, which is mediated by GRP-78/PERK/CHOP signaling. Key proteinase is present in maturation-stage enamel; KLK4 was also affected by fluoride, but rescued by 4-PBA. This study presents a possibility for therapeutic strategies for dental fluorosis, while further exploration is required.

TGF-β1/Smad3 Signaling Is Required to Alleviate Fluoride-Induced Enamel Hypomineralization

Excessive fluoride intake during enamel development can affect enamel mineralization, leading to dental fluorosis. However, its potential mechanisms remain largely unexplored. In the present study, we aimed to investigate the impact of fluoride on the expressions of RUNX2 and ALPL during mineralization and the effect of TGF-β1 administration on fluoride treatment. A dental fluorosis model of newborn mice and an ameloblast cell line ALC were both used in the present study. The mice of the NaF group, including the mothers and newborns, were fed with water containing 150 ppm NaF after delivery to induce dental fluorosis. The mandibular incisors and molars showed significant abrasion in the NaF group. Immunostaining, qRT-PCR, and Western blotting analysis indicated that exposure to fluoride markedly down-regulated RUNX2 and ALPL in mouse ameloblasts and ALCs. Besides, fluoride treatment significantly decreased the mineralization level detected by ALP staining. Furthermore, exogenous TGF-β1 up-regulated RUNX2 and ALPL and promoted mineralization, while the addition of SIS3 could block such TGF-β1-induced up-regulation. In TGF-β1 conditional knockout mice, the immunostaining of RUNX2 and ALPL was weaker compared with wild-type mice. Exposure to fluoride inhibited the expressions of TGF-β1 and Smad3. Co-treatment of TGF-β1 and fluoride up-regulated RUNX2 and ALPL compared with the fluoride alone treatment, promoting mineralization. Collectively, our data indicated that TGF-β1/Smad3 signaling pathway was necessary for the regulatory effects of fluoride on RUNX2 and ALPL, and the fluoride-induced suppression of ameloblast mineralization was mitigated by activating TGF-β1/Smad3 signaling pathway.

Sociodemographic, biological, and timing characteristics of dental caries and fluorosis using mixed-type cluster analysis on 12-year-olds in Ho Chi Minh city, 1989-2019

Objectives

In 1990, Ho Chi Minh City started Community water fluoridation (CWF) at 0.7 ppm F, and in 2000, it was adjusted to 0.5 ppm F. Here, we analyzed dental caries and fluorosis data in Ho Chi Minh City to explore commonalities associated with CWF among 12-year-old children.

Methods

Dental caries and fluorosis data were collected in 1989, 2003, 2012, and 2019 (N = 4773). Trained dentists scored dental caries using the WHO detection criteria and fluorosis using Dean's Fluorosis Index. We used these data and the k-prototypes method by the R package to identify clusters of participants with shared clinical and water fluoride levels.

Results

We used datasets 1 (4773 participants) and 2 (4194 participants, missing fluorosis data in 1989). K-prototypes analysis identified three clusters in each dataset. Cluster 1, with 80 % of the sample at 0.5 ppm F area characterized by low caries and fluorosis scores. Cluster 2 with 60 % of the sample non-fluoridated area had high caries and low fluorosis scores. Cluster 3, with 75 % of the sample in 0.7 ppm area, had low caries but borderline high fluorosis scores.

Conclusion

Identifying three clusters based on clinical and environmental scores supports the decision to fluoridate the water to prevent caries (0-0.7 ppm) and the shift from 0.7 to 0.5 ppm to keep the caries preventive effect while reducing the risk of fluorosis.

Clinical significance

Our results support the effectiveness of CWF in preventing dental caries and the appropriateness of changing the F concentration to reduce the risk of fluorosis while maintaining its effectiveness.

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

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

Effect of Long Non-coding RNA and DNA Methylation on Gene Expression in Dental Fluorosis

In the process of tooth development, the interaction between genetic information, epigenetic inheritance, and environment jointly affects the teeth formation. At present, the mechanism of dental fluorosis is rarely studied from transcriptomics, and there is no report on epigenetic perspective. In the study, SD rats were randomly divided into dental fluorosis group and control group fed with NaF (150 mg/L) or distilled water for 8 weeks. After 3.5 days of birth, the RNAs or DNA of rat mandibular molars were detected by RNA-seq or MethylTarget, respectively. The results demonstrated that a total of 1723 differentially expressed genes (DEGs) and 2511 differential expression lncRNAs (DE-lncRNAs) were mainly involved in the ion channels, calcium ion transport, and immunomodulatory signaling pathways. ATP2C1 and Nr1d1, which were related to Ca2+ transport, cellular calcium homeostasis, endoplasmic reticulum stress and immunity, may be the key genes in the formation of dental fluorosis. Notably, we also found that the immune response plays an important role in the formation of dental fluorosis, and a large amount of DEGs was enriched in immune regulation and NF-κB signaling pathways. Furthermore, the methylation levels of 13 sites were increased in Ago4, Atf3, Atp2c1, Dusp1, Habp4, and Mycl, while methylation levels of 5 CpG sites decreased in Ago4, Atp2c1, Habp4, and Traf6, and conformably, the expression of these genes have been significantly changed. This study comprehensively analyzed the occurrence mechanism of dental fluorosis from transcriptomics and epigenetics, so as to provide theoretical reference for further research.

Unraveling gene expression and genetic instability in dental fluorosis: Investigating the impact of chronic fluoride exposure

Chronic fluoride exposure, even in small quantities, when continuously ingested by the human population, can lead to a significant public health concern known as fluorosis. Our understanding of the effects of fluoride on human health, as well as its potential to impact DNA, is limited. The present study aimed to assess genetic instability in 20 individuals diagnosed with dental fluorosis and 20 individuals without the condition from the state of Rio Grande do Sul, Brazil. The participants' dental fluorosis was evaluated using the Thylstrup-Fejerskov index (TF). To further evaluate genetic instability, several assays were conducted, including the alkaline and modified (+FPG) comet assay (using a visual score, VS), the buccal micronucleus (MN) cytome (BMCyt) assay, the cytokinesis-block MN (CBMN-Cyt) assay, and the measurement of telomere length (TL). In addition, the study utilized tools from Systems Biology to gain insights into the effects of fluoride exposure on humans, which aided in the selection and evaluation of mRNA expression levels of specific genes, namely PPA1 (inorganic pyrophosphatase 1), AQP5 (Aquaporin 5), and MT-ATP6 (Mitochondrially Encoded Adenosine Triphosphate Synthase Membrane Subunit 6). Furthermore, fluoride levels in the blood and urine were assessed using an ion-selective electrode, along with the evaluation of the inflammatory response in serum. The group with dental fluorosis exhibited 2.18 times higher MN frequencies specifically when assessed using the CBMN-Cyt assay, in comparison with individuals without fluorosis. Findings from the enzyme-modified comet assay indicated oxidative damage to purines in DNA. Furthermore, a decrease in TL was observed, along with elevated expression patterns of the PPA1 and AQP5 genes, and significant alterations in cytokine release. Significant correlations were identified between the TF and age, as well as the levels of necrotic cells. Additionally, noteworthy correlations were established between fluoride levels and the levels of MN, VS, and MT-ATP6. Although dental fluorosis results from fluoride exposure, our research highlights the potential influence of this condition on genomic instability and gene expression. Consequently, our findings stress the importance of continuously monitoring populations with a high incidence of dental fluorosis to enhance our comprehension of how genomic instability might correlate with the origins and consequences of health problems in these individuals.

How to optimize bonding procedures on healthy and hypomineralized enamel in orthodontics?

Introduction

Bonding to enamel is a daily problem for the orthodontist. While bonding to healthy enamel is nowadays well mastered, bonding to hypomineralized enamel is much less so. The aim of this article was to help the orthodontist to optimise bonding, whatever the clinical situation.

Material and Method

Based on data from the literature, the clinical and microscopic characteristics of healthy and hypomineralised enamel, including amelogenesis imperfecta (AI), molar incisor hypomineralization (MIH), fluorosis or erosion will be described. Proposals for optimising bonding will then be identified and summarized.

Results

Bonding to enamel is reliable, but the use of an etch-and-rinse mode (even with a universal adhesive) is recommended. For AI, MIH and fluorosis, the use of sodium hypochlorite after etching seems to significantly increase bonding. No treatment is needed for eroded enamel. However, deep resin infiltration for severe MIH or superficial resin infiltration for fluorosis would reduce the risk of enamel fracture during bracket removal.

Conclusion

It is important to be aware of the characteristics of the dental substrate and the materials used to optimize procedures.

Fluoride in groundwater of industrial town of Sonbhadra district, Uttar Pradesh, India: probable release mechanism and potential health risk assessment

In the selected study region of Sonbhadra district, coal burning and mining activities are dominant. Previous studies reported F contamination in very few groundwater samples of this region. A detailed study is required to estimate the fluoride in groundwater of this area. Hence, a total of 128 groundwater samples were collected during post- and pre-monsoon seasons in the year 2017 to estimate the F-, its geochemistry, and health risk assessment from Renukoot and Anpara industrial clusters of Sonbhadra district, Uttar Pradesh, India. The pH of groundwater samples varied from slightly acidic to alkaline during both seasons. Almost all the major cations (Ca2+, Mg2+, Na+, and K+) and major anions (HCO3-, Cl-, SO42-, and F-) values in groundwater samples of both clusters were found within the permissible limit of World Health Organization (WHO) and Beauro of Indian standards except F- in both seasons. The scatter plots of F- with Ca2+, Na+, HCO3-, and pH are used to explain the release mechanism of fluoride in groundwater. Saturation indices (SI) calcite versus SI fluorite and SI dolomite versus SI fluorite plots of both clusters used to check the involvement of these minerals in fluoride enrichment of aquifers. F- contamination in groundwater due to coal burning in coal mining and thermal power plant dominated region is discussed globally and locally both. The non-carcinogenic health risk due to consumption of fluoride-contaminated water is estimated by using target hazard quotient (THQ). THQ values of F- showed that children are at high risk than adults in both clusters of the study area during both seasons. Pictorial representation is used to show the dental fluorosis cases in children of the study region.

MiR-1a-3p Inhibits Apoptosis in Fluoride-exposed LS8 Cells by Targeting Map3k1

Dental fluorosis is a common chemical disease. It is currently unclear how fluorosis occurs at the molecular level. We used miRNA-seq to look at the differences between miRNAs in the cell line of ameloblasts LS8 that had been treated with 3.2 mmol/L NaF. We also performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. miR-1a-3p levels were significantly lower in mouse LS8 cells treated with 3.2 mmol/L NaF, and miR-1a-3p-targeted genes were significantly enriched in the MAPK pathway. LS8 cells were divided into four groups: control, NaF, NaF+miR-1a-3p mimics, and NaF+miR-1a-3p mimics normal control groups. Cellular morphology was observed by an inverted microscope, and the proliferation activity of LS8 cells was assessed by Cell Counting Kit-8 (CCK-8). Using the real-time quantitative polymerase chain reaction (RT-qPCR), transcription levels of miR-1a-3p and Map3k1 were detected. The expressions of Bax, Bcl-2, Map3k1, p38MAPK, ERK1/2, p-p38MAPK, and p-ERK1/2 were measured by Western blot. After bioinformatics analysis, we used a luciferase reporter assay (LRA) to validate the target of miR-1a-3p, showing that miR-1a-3p could inhibit apoptosis while increasing proliferation in fluoride-exposed LS8 cells. Generally, miR-1a-3p might directly inhibit Map3k1, reduce MAPK signal pathway activation, and promote phosphorylation. Thus, our findings revealed that the interaction of miR-1a-3p with its target gene Map3k1 and MAPK signal pathway might decrease the apoptosis of LS8 cells treated with 3.2 mmol/L NaF.

Microstructural Analysis of Cancellous Bone in Fluorosis Rats

Skeletal fluorosis likely alters bone structural properties on the cortical and cancellous tissue levels in view that fluorine ion replaces bone mineral composition. Our previous study showed high bone turnover occurred in cortical bone of skeletal fluorosis. Therefore, this study further analyzed the microstructure of cancellous bone in fluorosis rats. Rats were randomly assigned into three groups: the control, low-dose fluoride group (10 mgF-/kg·day), and high-dose fluoride group (20 mgF-/kg·day). Rats were orally administered with fluoride for 1, 2, and 3 months of periods. The trabecular bone parameters of tibia were detected with micro CT and analyzed with software. The activities of glutathione peroxidase (GPX), superoxide dismutase (SOD), and the content of malondialdehyde (MDA) in serum were measured. Results showed that severity of dental fluorosis rose with the increase of dose and prolongation of fluoride exposure. Meantime, the poorer connectivity and less trabecular bone network were observed in cancellous bone of rats treated with fluoride. Data analysis indicated that fluoride treatment significantly decreased bone volume and connectivity degree, but amplified trabecular space in 1 and 2 months of periods. Intriguingly, trabecular thickness significantly decreased in 1-month high-dose fluoride group, but returned to the control in 3 months of period. Fluoride treatment mainly inhibited the GPX activity and increased the MDA level to activate oxidative stress. This study confirmed that excessive fluoride impaired cancellous bone and caused redox imbalance.

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

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

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

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

Impact of dental fluorosis on the oral health related quality of life of adolescents in an endemic area

Introduction

Oral diseases and conditions affect the physical, social, and psychological well-being of an individual. The aim of this study was to determine the association between the severity of dental fluorosis and oral health related quality of life (OHRQoL) among 15-year-old school children residing in an endemic area for dental fluorosis in Sri Lanka.

Design

A cross-sectional study was conducted among 989, 15-year-old school children who were lifetime residents of Kurunegala district. A validated Sinhala version of the Child Perception Questionnaire (CPQ 11-14) was used to assess OHRQoL. Dental fluorosis was assessed using the Thylstrup and Ferjeskov index (TF index) while dental caries and malocclusion were assessed using the WHO Basic Methods and Dental Aesthetics Index (DAI) respectively. In addition, information pertaining to parental level of education, type of toothpaste used, frequency of toothbrushing and use of dental services was also gathered.

Results

The prevalence of dental fluorosis was 52%. The overall prevalence of impacts based on the CPQ was 38.2%. The severity of dental fluorosis was not significantly associated with the overall prevalence of impacts. However, the severity of dental fluorosis was significantly associated with three oral impacts namely "having pain in teeth, lips, jaws, or mouth", "felt irritable or frustrated" and "other children teased or called names". According to the multiple logistic regression analysis, use of dental services and moderate to severe malocclusion were significantly associated with poor OHRQoL but not dental fluorosis.

Conclusion

The severity of dental fluorosis was not associated with OHRQoL of the participants.

A Bibliometric Analysis of the Top 100 Most-Cited Papers Concerning Dental Fluorosis

A high number of citations can indicate the potential of any specific paper to influence other research and generate changes in clinical practice. Analyzing the most-cited papers in a certain scientific field may assist researchers to identify the influential papers as well their main characteristics. The present study aimed to analyze the 100 most-cited papers concerning dental fluorosis (DF) through a bibliometric review. A search was performed in the Web of Science Core Collection (WoS-CC) database in November 2021. The papers were displayed in descending order according to the number of citations in WoS-CC. Two independent researchers performed the selection. Scopus and Google Scholar were used to compare the number of citations with WoS-CC. The following data were extracted from the papers: title, authors, number and density of citations, institution, country, continent, year of publication, journal title, keywords, study design, and theme. Collaborative networks were generated using the VOSviewer software. The top 100 most-cited papers were published between 1974 and 2014 and were cited 6,717 times (ranging from 35 to 417). Community Dentistry and Oral Epidemiology (24%), Journal of Dental Research (21%), Journal of Public Health Dentistry (17%), and Caries Research (13%) published the most papers. Observational studies (60%) and literature reviews (19%) were the most common study designs. The main topics were epidemiology (44%) and fluoride intake (32%). The countries with the highest number of papers were the USA (44%), Canada (10%), and Brazil (9%). The University of Iowa (USA) had the most papers (12%). Levy SM was the author with the highest number of papers (12%). The 100 most-cited papers on DF were mainly observational studies focused on epidemiology and originated in North America. There were few interventional studies and systematic reviews among the most-cited papers concerning this topic.

A Systematic Review and Meta-Analysis of the Relationship Between the Severity of Dental Fluorosis and Fluoride Biomarkers in Endemic Areas

The intake of high concentrations of fluoride, mainly through drinking water, diet and fluoridated dentifrices, produces fluorosis, which in its early stages is manifested as dental fluorosis (DF). To recognize exposure to fluoride in endemic areas and to evaluate the risk of developing health impairment, the WHO has established several biomarkers that are used to determine systemic fluorine (F^-) exposure. Thus, the aim of this study was to conduct a systematic review and meta-analysis of the relationship between the severity of DF and fluoride biomarkers in endemic areas. The protocol of this study was previously registered as CRD42021244974. A digital search was carried out in PubMed/Medline, SpringerLink, Scopus, Cochrane and Google Scholar by employing the keywords "urine", "nails", "hair", "plasma", "saliva" and "dental fluorosis" for the original studies with content associated with F^- for the biomarkers and DF. The mean difference was established as the effect measure for the meta-analysis. Seven studies fulfilled the eligibility criteria, among which five assessed urine and two employed nails as fluoride biomarkers. A positive significant difference was found between the biomarkers and the severity of DF (0.27, p < 0.001) and individually for each biomarker (urine: 0.14, p = 0.001; nails: 0.88, p < 0.05). The F^- concentration in urine and nails is correlated with the severity of DF, with the most evident differences between healthy individuals and those with mild severity. Both biomarkers are adequate to assess this relationship in endemic areas of fluoride and DF.

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

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

Analysis of multiple pathways and levels of fluoride intake in fluorosis areas of Southwest China

In the coal-burning fluorosis areas of China, over 10 million people suffer from dental fluorosis caused by multiple pathways of fluoride intake. However, the link between dental fluorosis prevalence, the geochemical distribution of fluoride, and contributions of different exposure pathways remain unclear. Here, we aimed to quantify the various fluoride exposure pathways and establish the association between dental fluorosis and fluoride intake in Southwest China. Epidemiological data on the peak time of fluorosis prevalence were combined with geochemical analyses of the fluoride content in coal and clay over a large scale, the amounts and ratios of fluoride intake through different exposure pathways were calculated, and the association between the total daily fluoride intake (TDFI) and dental fluorosis severity was analyzed. The prevalence of dental fluorosis was not significantly correlated with the fluoride geo-background of coal and clay on a large scale (P > 0.05). The co-combustion of coal and clay contained in hand-made briquettes is the main pathway of fluoride contamination, which occurs through the inhalation of polluted air and consumption of contaminated roasted products. Furthermore, the TDFI per person ranged from 2.78 to 17.32 mg, and it was significantly positively correlated with the prevalence of dental fluorosis (P < 0.05). The TDFI from breathing and eating was 1.1-3.2 mg and 1.1-15.1 mg, which accounted for 9%-54% and 40%-90% of the total TDFI, respectively. The combination of living habits and soil geochemical fluoride anomalies resulted in the higher prevalence of fluorosis in rural areas of Southwest China.

Sodium Fluoride and Sulfur Dioxide Derivatives Induce TGF-β1-Mediated NBCe1 Downregulation Causing Acid-Base Disorder of LS8 Cells

The aim of the present work was to assess whether the combination of sodium fluoride (NaF) and sulfur dioxide derivatives (SO₂ derivatives) affects the expression of the electrogenic sodium bicarbonate cotransporter NBCe1 (SLC4A4), triggering an acid-base imbalance during enamel development, leading to enamel damage. LS8 cells was taken as the research objects and fluorescent probes, quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and factorial analysis were used to clarify the nature of the fluoro-sulfur interaction and the potential signaling pathway involved in the regulation of NBCe1. The results showed that exposure to fluoride or SO₂ derivatives resulted in an acid-base imbalance, and these changes were accompanied by inhibited expression of NBCe1 and TGF-β1; these effects were more significant after fluoride exposure as compared to exposure to SO₂ derivatives. Interestingly, in most cases, the toxic effects during combined exposure were significantly reduced compared to the effects observed with fluoride or sulfur dioxide derivatives alone. The results also indicated that activation of TGF-β1 signaling significantly upregulated the expression of NBCe1, and this effect was suppressed after the Smad, ERK, and JNK signals were blocked. Furthermore, fluoride and SO₂ derivative-dependent NBCe1 regulation was found to require TGF-β1. In conclusion, this study indicates that the combined effect of fluorine and sulfur on LS8 cells is mainly antagonistic. TGF-β1 may regulate NBCe1 and may participate in the occurrence of dental fluorosis through the classic TGF-β1/Smad pathway and the unconventional ERK and JNK pathways.

Possible Association Between Polymorphisms in ESR1, COL1A2, BGLAP, SPARC, VDR, and MMP2 Genes and Dental Fluorosis in a Population from an Endemic Region of West Bengal

Dental fluorosis (DF) is the most prevalent form of fluorosis in India affecting millions of people all over the country. As estrogen receptor 1 (ESR1), collagen type 1 alpha 2 (COL1A2), bone γ-carboxyglutamic acid protein (BGLAP), secreted protein acidic and cysteine-rich (SPARC), vitamin D receptor (VDR), and matrix metallopeptidase 2 (MMP2) genes play critical roles in bone metabolism, bone formation, mineral metabolism, and mineralization, variants in these genes could influence susceptibility to DF. The present study was aimed at evaluating the association between 15 single-nucleotide polymorphisms (SNPs) in the six candidate genes (namely, ESR1, COL1A2, BGLAP, SPARC, VDR, and MMP2) and DF among 132 individuals (case = 71 and control = 61) living in a fluoride endemic region of West Bengal, India. No statistically significant association with disease risk was found when the genotypes and allele frequencies of each of the 15 SNPs was analyzed individually using odd's ratio with 95% confidence interval. "CC" and "AG" haplotypes of the COL1A2 gene showed a borderline association with DF. The present study is the first in India to use multifactor dimensionality reduction (MDR) analysis for identifying gene-gene and gene-environment interactions in fluorosis. The biomarker of serum fluoride showed a significant association with the disease state among the 17 attributes (15 SNPs and 2 biomarkers of urine fluoride and serum fluoride) (P value = 0.011). The best model of MDR analysis with maximized testing accuracy involved two SNPs from the ESR1 gene (rs9340799 and rs2077647) and one SNP from BGLAP gene (rs1543294) (P value < 0.0001).

Novel machine learning techniques based hybrid models (LR-KNN-ANN and SVM) in prediction of dental fluorosis in groundwater

Studies have shown that excessive intake of fluoride into human body from drinking water may cause fluorosis adversely affects teeth and bones. Fluoride in water is mostly of geological origin and the amounts depend highly on many factors such as availability and solubility of fluoride minerals as well as hydrogeological and geochemical conditions. Chemical methods usually accomplish fluoride analysis in drinking water. The chemical methods are expensive, labor-intensive and time-consuming in general although accurate and reliable results are obtained. An alternative cost-effective approach based on machine learning (ML) technique is investigated in this study. Furthermore, most effective input parameters are selected via proposed Simulated Annealing (SA) search scheme. Selected subset (SAR, K⁺, NO₃^-, NO₂^-, Mn, Ba and Fe) by SA algorithm exhibited high correlation coefficient values of 0.731 and strong t test scores of 5.248. On the other hand, most frequently selected individual features were identified as NO₃^-, NO₂^-, Fe and SAR by vote map. The results of experiments revealed that selected feature subset improves the prediction performance of the learning models while feature size is reduced substantially. Thus it eventually enabled determination of fluoride in a cheap, fast and feasible way.

Arsenic and fluoride co-exposure through drinking water and their impacts on intelligence and oxidative stress among rural school-aged children of Lahore and Kasur districts, Pakistan

Arsenic (As), and fluoride (F^-) are potent contaminants with established carcinogenic and non-carcinogenic impacts on the exposed populations globally. Despite elevated groundwater As and F^- levels being reported from various regions of Pakistan no biomonitoring study has been reported yet to address the co-exposure impact of As and F^- among school children. We aimed to investigate the effects of these two contaminants on dental fluorosis and intelligence quotient (IQ) along with the induction of oxidative stress in rural children under co-exposed conditions. A total of 148 children (5 to 16 years old) from the exposed and control group were recruited in the current study from endemic rural areas of Lahore and Kasur districts, Pakistan having elevated As and F^- levels in drinking water than permissible limits. We monitored malondialdehyde and its probable association with antioxidants activity (SOD, CAT, and GR) as a biomarker of oxidative stress. GSTM1/T1 polymorphisms were measured to find the impact of As on health parameters. Mean urinary concentrations of As (2.70 vs. 0.016 µg/L, P < 0.000) and F^- (3.27 vs. 0.24 mg/L, P < 0.000) as well as the frequency of dental fluorosis were found elevated among the exposed group. The cases of children with lower IQ were observed high in the exposed group. Additionally, lower concentrations of antioxidants (SOD, CAT, and GR) were found suggesting high susceptibility to F^- toxicity. The findings suggest that F^- accounted for high variations in health parameters of children under the co-exposure conditions with As.

Essence of hydroxyapatite in defluoridation of drinking water: A review

Hydroxyapatite (HAP) is an easily synthesizable, low-cost mineral that has been recognized as a potential material for fluoride removal. Some of the synthesis methods of HAP are quite straightforward and cost-effective, while some require sophisticated synthesis techniques under advanced laboratory conditions. This review assesses the physicochemical characteristics of HAP and HAP-based composites produced via various techniques, their recent development in defluoridation and most importantly, the fluoride removal performances. For the first time, fluoride removal performances of HAP and HAP composites are compared based on partition coefficient (K_D) instead of maximum adsorption capacity (Q_max), which is significantly influenced by initial loading concentrations. Novel HAP tailored composites exhibit comparatively high K_D values indicating the excellent capability of fluoride removal along with specific surface areas above 120 m²/g. HAP doped with aluminium complexes, HAP doped ceramic beads, HAP-pectin nanocomposite and HAP-stilbite nanocomposite, HAP decorated nanotubes, nanowires and nanosheets demonstrated high Q_max and K_D. The secret of HAP is not the excellent fluoride removal performances but best removal at neutral and near-neutral pH, which most of the defluoridation materials are incapable of, making them ideal adsorbents for drinking water treatment. Multiple mechanisms including physical surface adsorption, ion-exchange, and electrostatic interactions are the main mechanisms involved in defluoridation. Further research work must be focused on upscaling HAP-based composites for defluoridation on a commercial scale.

Influence of climate on groundwater fluoride in different climatic domains in a hard rock terrain of Sri Lanka: implications to community health

Health risks associated with excessive intake of fluoride through drinking water are one of the geoenvironmental health problems observed in many parts of the world, mainly in countries of the humid tropical belt, including Sri Lanka. Fluoride-related health problems are widespread in the dry climatic region compared to the wet climatic zone of Sri Lanka. The potential health risks of fluoride for communities in a river basin which drains through two climatic zones, viz. wet and dry zones, were investigated in this study. Sixty-three groundwater samples were collected from wells in the Walawe river basin during pre- and post-monsoon periods. From collected samples, ten selected samples were analyzed for their tritium (³H) levels to find out the approximate resident time of groundwater. In the river basin, the dry zone segment is characterized by elevated levels of fluoride (> 1.0 mg/L) in groundwater. Groundwater fluoride in the region was primarily of geogenic origin. The tritium values showed older groundwater contained higher fluoride levels, showing a increased dissolution of fluoride-bearing minerals. The hazard quotient (HQ_fluoride) showed that about 45% of pre- and 55% of post-monsoon groundwater samples in the dry zone area were unsuitable for drinking purposes for school children who are vulnerable to non-carcinogenic risks and dental fluorosis. This study emphasizes the need for continuous water quality monitoring and mitigation measures to ensure the health of residents.

Dental Fluorosis and Its Associated Factors Amongst Libyan Schoolchildren

BACKGROUND

Little is known about dental fluorosis (DF) in Benghazi, Libya, where the public water supply is naturally fluoridated.

OBJECTIVE

The study aims to investigate the distribution of DF and its related risk factors and impact on oral health-related quality of life (OHRQoL) and the association between DF and caries amongst Libyan school children.

METHODS

A cross-sectional survey was carried out amongst 12-year-old schoolchildren in the city of Benghazi. Dean's and decayed, missing, and filled surfaces (DMF) indices were used to assess the severity of DF and dental caries. In addition, a self-administered questionnaire was used to collect sociodemographic and behavioural information and OHRQoL using the Child Oral Health Impact Profile-Short Version 19 (COHIP-SF19).

RESULTS

Out of 1125 children who participated in the study, 15%, 7.8%, 2.2%, and 0.4% of participants were coded as having questionable, mild, moderate, and severe DF, respectively. Children enrolled in private schools were less likely to have DF (odds ratio, 0.55; 95% confidence interval, 0.35-0.83; P = .007). Moderate-severe DF was associated with more decayed surfaces and DMF scores and low scores for COHIP-SF19 and its socioemotional well-being subscale.

CONCLUSIONS

The data demonstrate that rates of DF are relatively low in naturally fluoridated areas in Libya. DF amongst Libyan schoolchildren was associated with social disparities, higher caries rates, and negative impacts on OHRQoL.

Fluoride levels in river water from the volcanic regions of Cauca (Colombia)

Fluoride concentrations of 0.5 mg/L in drinking water are considered useful for dental caries prevention. However, fluoride concentrations higher than 1.2 mg/L in water can pose a risk of dental fluorosis due to high exposure to fluoride. The objective is to determine the fluoride concentration in water from aqueducts of different Colombian municipalities of Cauca (Popayán, Coconuco, and Puracé) to assess the fluoride dietary intake from the consumption of this water. A total of 66 water samples have been taken from Popayán, Coconuco, and Puracé. Fluoride content was determined by fluoride ion-selective electrode (ISE) potentiometry. The fluoride concentrations recorded in Coconuco and Puracé water were ≤ 0.002 mg/L. The mean fluoride content recorded in the Popayán water was 0.42 mg/L, with its highest concentration in Cauca River water (0.83 mg/L). Considering the admissible intake values, the water from Popayán confers remarkable fluoride intakes, especially in children with high percentages of contribution to the admissible daily intake (46.7% to 7- to 12-month children and 41.5% to 1- to 3-year children). The fluoride content in the water of Coconuco and Puracé does not reach an optimal value (< 0.5 mg/L) for the protective effect against dental caries, while the water of the main Cauca River basin does reach the optimal value. Likewise, the intake of fluoride from the consumption of the analyzed water does not confer any health risk. However, the implementation of monitoring systems for fluoride levels is recommended in order to safeguard the consumer's health.

Are there associations between the occurrence of dental fluorosis and the experience of dentine hypersensitivity? A cross-sectional study

OBJECTIVES

Associations between the occurrence of dentine hypersensitivity (DH) and dental fluorosis (DF) have been suggested. Testing this association requires studies among populations with both conditions. This study aimed to determine the association between DF and the experience of DH among a population endemic for DF.

METHODS

This was a cross-sectional study conducted in 2021 over 6 months among 428 adult patients. Participants' demographics were collected, followed by verbal screening for DH and oral examinations. Clinical assessment for DH was carried out by tactile and evaporative methods. The presence and severity of DF were also assessed using the Thylstrup and Fejerskov Index. Data analysis included Chi-square and correlation statistics to assess the presence and strength of associations.

RESULTS

The overall prevalence of DH was 31.1%. A higher proportion (41.1%, P < 0.001) of participants with DF had DH than those without DF. The association between DH and DF was minimal but statistically significant (r = 0.174, P < 0.001). Among those with DF, the prevalence of DH was highest in participants with severe fluorosis (50%, P = 0.740). The proportion of sensitive teeth to the teeth examined was significantly higher (P < 0.0001) for participants with DF (289/4167, 6.9%) than participants without DF (267/6758, 4%). This proportion was also highest for severe DF (20/254, 7.9%, P = 0.572) than the mild and moderate forms.

CONCLUSION

DH was more prevalent among individuals with DF. The prevalence of DH was not dependent on the severity of DF.

Dental fluorosis among 15- year- old school children in an endemic district in Sri Lanka

AIM

To determine the prevalence, severity, and intraoral distribution of dental fluorosis among 15-year-old school children in Kurunegala district of the North-Western Province, Sri Lanka.

METHOD

A cross-sectional study was conducted among 15-year-old school children residing in Kurunegala district since birth. One thousand and forty participants from 42 schools were selected using two stage cluster sampling method. A single calibrated dentist examined all participants for dental fluorosis using Thylstrup and Ferjeskov index. Water samples from the drinking water source of participants were analyzed for their fluoride content.

RESULTS

The prevalence of dental fluorosis was 52% and 42% when TF score ⟩ 0 and TF score ⟩1 were considered as cut-offs for dental fluorosis respectively. Of those with dental fluorosis, a majority (20.9%) had a TF score of 2. Only 0.5% had a TF score of 6 which was the highest score observed for any participant. With regards to the intra-oral distribution of dental fluorosis, the premolars were the most affected teeth and the least affected were the central incisors. The fluoride levels in the drinking water source ranged between 0.0-1.9 mg/L and the prevalence of dental fluorosis increased with the increase in the fluoride level in drinking water source.

CONCLUSIONS

The prevalence of dental fluorosis was high and it increased with the increase in the fluoride content in the drinking water source.

Moderating Role of TSHR and PTPN22 Gene Polymorphisms in Effects of Excessive Fluoride on Thyroid: a School-Based Cross-Sectional Study

We aimed to investigate the relationship between the effects excessive of fluoride on thyroid health in children and the moderating role of thyroid stimulating hormone receptor (TSHR) or protein tyrosine phosphatase nonreceptor-22 (PTPN22) gene polymorphisms. Four hundred thirteen children (141 with dental fluorosis and 198 boys) were enrolled from both historical endemic and non-endemic areas of fluorosis in Tianjin, China. The fluoride exposure levels, thyroid health indicators, and TSHR (rs2268458) and PTPN22 (rs3765598) polymorphisms were examined. Multiple logistic models were applied to evaluate the relationship between dental fluorosis and thyroid abnormalities. Children over 9 year old with dental fluorosis have lower FT₄ and TGAb levels and thyroid volume and higher TPOAb levels (all P < 0.05). In overall participants, children with dental fluorosis were more likely to have thyroid antibody single positive issues (adjusted P = 0.039) and less likely to have a goiter according to age or body surface area (age or BSA) (adjusted P = 0.003); In the TSHR (rs2268458) SNP = CC/CT or PTPN22 (rs3765598) SNP = CC subgroup, dental fluorosis may cause thyroid antibody single positive (adjusted P = 0.036; adjusted P = 0.002); in the TSHR (rs2268458) SNP = TT or PTPN22 (rs3765598) SNP = CC subgroup, dental fluorosis may protect children from goiter (age or BSA) (adjusted P = 0.018; adjusted P = 0.013). Excessive fluoride may induce thyroid antibody single positive and reduce goiter in children. Heterogeneity exists in the relationship between excessive fluoride and thyroid antibody single positive or goiter issues across children carrying different TSHR (rs2268458) or PTPN22 (rs3765598) genotypes.

Exposure Assessment of Fluoride Intake Through Commercially Available Black Tea (Camellia sinensis L.) from Areas with High Incidences of Chronic Kidney Disease with Undetermined Origin (CKDu) in Sri Lanka

Fluoride is a beneficial trace element for human health as its deficiency and excess levels can cause detrimental health effects. In Sri Lanka, dry zone regions can have excessive levels of fluoride in drinking water and can cause dental and skeletal fluorosis. In addition to drinking water, traditional habits of tea consumption can cause an additional intake of fluoride in the population. A total number of 39 locally blended black tea samples were collected from a village where chronic kidney disease with undetermined origin (CKDu) is prevalent. In addition, unblended tea samples were obtained from tea-producing factories. The fluoride contents in infusions of 2% weight per volume (w/v) were measured using calibrated ion-selective fluoride electrodes. The mean fluoride content was 2.68±1.03 mg/L in loose tea, 1.87±0.57mg/L in packed tea samples, and 1.14±0.55 mg/L in unblended tea. Repeated brewing of the same tea leaves showed that over 50% of fluoride leached into the solution in the first infusion. An estimate of the daily total average fluoride intake via tea consumption per person is 2.68 mg per day. With groundwater in many dry zone regions in Sri Lanka showing high fluoride levels that exceed 0.5 mg/L, the additional daily intake can rapidly exceed recommended thresholds of 2 mg/day. This can add to adverse health impacts that might also relate to CKDu.

Effect of Fluoride in Drinking Water on Fecal Microbial Community in Rats

Intestinal nutrition has a close association with the onset and development of fluorosis. Intestinal microbes play a major role in intestinal nutrition. However, the effect of fluoride on intestinal microbes is still not fully understood. This study aimed to evaluate the dose-response of fluoride on fecal microbes as well as the link between fluorosis and fecal microbes. The results showed that fluoride did not significantly alter the diversity of fecal microbiota, but richness estimators (ACE and Chao) increased first, and then decreased with the increase of water fluoride. At the genus level, 150 mg/L fluoride significantly reduced the abundances of Roseburia and Clostridium sensu stricto, and 100 mg/L and 150 mg/L fluoride obviously increased the abundances of Unclassified Ruminococcaceaes and Unclassified Bdellovibrionales, respectively. The correlation analysis showed fluoride exposure had a negative association with Roseburia and Turicibacter and was positively associated with Pelagibacterium, Unclassified Ruminococcaceae, and Unclassified Bdellovibrionales. Dental fluorosis was negatively associated with Clostridium sensu stricto, Roseburia, Turicibacter, and Paenalcaligenes and had a positive association with Pelagibacterium, Unclassified Ruminococcaceae, and Unclassified Bdellovibrionales. In conclusion, this study firstly reports fluoride in drinking water has a remarkable biphasic effect on fecal microbiota in rats, and some bacteria are significantly associated with fluoride exposure and dental fluorosis. These results indicate the gut microbiota may play an important role in fluorosis, and some bacteria are likely to be developed as biomarkers for fluorosis.

The influence of fluoride in drinking water on the incidence of fluorosis and intelligence of elementary school students in Palu City

OBJECTIVE

This research aims to know the influence of fluoride in drinking water towards Fluorosis and the Intelligence Level of Elementary School Students in Palu City.

METHOD

This cross-sectional study was performed through descriptive analysis on 100 students aged 6-12 years old selected by stratified random sampling from two different areas with different levels of fluoride in drinking water in Palu City. The samples were collected from two different elementary schools which were SDN 2 Talise and SDN Inpres 1 Birobuli. The examination was performed by a dentist using Dean's Fluorosis Index and philology, who measured students' IQ using Raven's Coloured Progressive Matrices.

RESULTS

High level of F in drinking water affects the fluorosis status of students (p=0.001), in which among 40 students (40%) who experienced fluorosis, 38 (38%) of them are from the area whose F level is high. The high level of F also affected the children's IQ, obtaining a p-value of 0.001, showing that there were no students with low IQ found in the area with low F level. For the status of Fluorosis and IQ, p=0.001 was obtained. Among the 60 students who did not experience fluorosis, 96.6% of them had a high IQ level.

CONCLUSION

The recent research found that fluorosis was found more often in the area of which F level was high, where the IQ level of the students was found to be lower compared to the students who loved in the area with low F level.

Dental fluorosis among people and livestock living on Gihaya Island in Lake Kivu, Rwanda

BACKGROUND

Dental fluorosis is caused by prolonged exposure to excessive fluoride during the period of permanent tooth formation and is characterized by tooth discoloration, pitting, and loss of shape. Communities living near Lake Kivu in Western Rwanda exhibit a high prevalence of dental fluorosis; however, data on prevalence and risk factors are scarce.

METHODS

This cross sectional, quantitative study used a One Health approach to investigate dental fluorosis prevalence among people and livestock and to measure fluoride content in the environment. In 2018, oral health examinations were conducted to assess the prevalence of fluorosis in children (aged 9 to 15 years), cattle and goats residing on Gihaya Island (Rwanda, East Africa). All children and cattle/goats meeting basic eligibility criteria (e.g., island residence) were invited to participate. Presence and severity of dental fluorosis was categorized according to the Dean's Fluorosis Index. Samples of local foods, water, soil and grass were collected from communal sources and individual households and analyzed for fluoride content using standard laboratory techniques. Descriptive and binomial analyses (Fisher Exact Test) were used to assess this dataset.

RESULTS

Overall, 186 children and 85 livestock owners (providing data of 125 livestock -23 cattle and 102 goats) participated. Dental fluorosis was recorded in 90.7% of children and 76% of livestock. Moderate to severe fluorosis was observed in 77% children while goats and cattle most often exhibited mild or absent/questionable severity, respectively. Water from Lake Kivu (used primarily for human cooking water and livestock drinking water) contained fluoride levels that were consistently higher than the maximum threshold (1.5 mg/L) recommended by the World Health Organization. Other sources (borehole and rainwater) were within safe limits. All food, soil and grass samples contained fluoride. The highest levels were observed in porridge (0.5 mg/g) and small fishes (1.05 mg/g).

CONCLUSIONS

Altogether, dental fluorosis was highly prevalent among children and goats on Gihaya Island with various food and water sources contributing a cumulative exposure to fluoride. An immediate and coordinated response across human, animal and water professionals is needed to reduce fluoride exposure within safe limits for island residents.

Determination of the Fluoride Content in Water of Aqueducts of Cauca (Colombia) by Ion Exchange Chromatography

Water for human consumption is the main source of fluoride exposure. The concentration in water should not exceed 1 mg/L of fluoride since, at higher levels; it increases the risk of dental fluorosis, among other adverse effects. The fluoride content of 149 water samples from different aqueducts in Cauca (Colombia) has been determined by ion exchange chromatography with the aim of fluoride risk assessment. The rural area of the Municipality of Santander de Quilichao registered fluoride concentrations between 0.012 and 0.150 mg/L. The urban area of Santander de Quilichao recorded lower fluoride levels than the rural area (0.027-0.068 mg/L). The urban area of the Municipality of Cajibío registered fluoride levels of 0.082-0.186 mg/L. The highest levels of fluoride were found in Timbío (0.121-0.210 mg/L). The fluoride levels recorded in this study are not considered sufficient to trigger dental fluorosis. Likewise, optimal levels are not considered to protect the child population against dental caries. However, a monitoring plan of fluoride concentrations in water should be implemented to assure the quality and safe of the water.

Fluoride concentrations in drinking water and health risk assessment in the south of Algeria

Drinking water is the primary source of fluoride intake by humans worldwide. Algeria, Africa's largest country, has been reported to have moderate to high fluoride levels in the water, particularly in the Southern and Saharan regions. In the south of Algeria, dental fluorosis is considered an epidemic that is spreading within the population by health professionals. This study aimed to determine fluoride concentrations in drinking water consumed by Ouargla population (south-east of Algeria) in 2021, assess non-carcinogenic health risk via daily human intake, and calculate the upper acceptable fluoride concentration in drinking water by Galgan and Vermillion formula. Forty-two water samples were collected during the spring season. The fluoride was measured using a validated spectrophotometric method. Hazard quotient of fluoride (HQ) and estimated daily intake (EDI) were calculated. The results reveal a mean fluoride level of 1.07 ± 0.38 mg/L, below WHO recommendation. Fluoride concentrations in water were higher in rural areas than in the central city (p = 0.05). HQ values were less than one for adults but greater than 1 for infants and children, suggesting health risks associated with water consumption for these vulnerable groups (p = 0.007). The main contribution of this study is the establishment of a database concerning fluoride levels and hazard quotient in the south of Algeria. Monitoring drinking water and control fluorosis is essential to avoid potential health risks.

Esthetic and Functional Rehabilitation of an Adolescent Patient with Severe Dental Fluorosis: A Clinical Report

Dental fluorosis is a developmental defect affecting amelogenesis. It presents clinically in different forms depending on the concentration, duration, and time of exposure to fluoride. Several therapeutic modalities have been described to manage mild and moderate forms of dental fluorosis; however, limited literature is available on the restorative management of severe forms of dental fluorosis, specifically in young individuals. This clinical report describes a complete prosthodontic rehabilitation of an adolescent patient with severe dental fluorosis affecting his permanent dentition. The patient was treated with a combination of monolithic, minimally-veneered zirconia crowns and direct composite resins. At the 1-year follow-up appointment, there were no complications, and both the patient's oral health and the integrity of the restorations remained stable.

Dental fluorosis prevalence in Saudi Arabia

Aim

In order to improve the understanding of dental fluorosis prevalence in Saudi Arabia and have a good idea of the quality of the studies that have been conducted, a systematic review was conducted to evaluate the prevalence of dental fluorosis among people who live in Saudi Arabia.

Methods

Online databases EMBASE and MEDLINE and the Cochrane Library were searched, without any restriction regarding age. In addition, there were no study design filters applied to the search engine. Study selection and data extraction were conducted in duplicate. Studies were included if they were conducted in Saudi Arabia on any population (adults and children) and collected dental fluorosis data. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of the studies. A narrative synthesis was conducted.

Results

Seven cross-sectional studies were identified. Areas of weakness in study design/conduct were low response rates, and identification and handling of confounding factors. Statistical pooling of data was not appropriate due to substantial heterogeneity, due in part to variation in sample size, variation of water fluoridation concentration, index used, targeted population and age group. Seven studies present dental fluorosis at any level. The proportion of dental fluorosis prevalence at any level ranged from 0.00 to 0.91. Six studies explored the prevalence of dental fluorosis of aesthetic-only level of concern. The proportion of dental fluorosis in this category ranged from 0.07 to 0.76.

Conclusion

The proportion of dental fluorosis at any level ranged from 0.00 to 0.91 and fluorosis at aesthetics level ranged from 0.07 to 0.76. However, current data does not provide a complete assessment of dental fluorosis across Saudi Arabia. Existing studies are limited in terms of the population covered. The included studies had methodological flaws.

The cholinergic system, intelligence, and dental fluorosis in school-aged children with low-to-moderate fluoride exposure

Disruption of cholinergic neurotransmission can affect cognition, but little is known about whether low-to-moderate fluoride exposure affects cholinergic system and its effect on the prevalence of dental fluorosis (DF) and intelligence quotient (IQ). A cross-sectional study was conducted to explore the associations of moderate fluoride exposure and cholinergic system in relation to children's DF and IQ. We recruited 709 resident children in Tianjin, China. Ion selective electrode method was used to detect fluoride concentrations in water and urine. Cholinergic system was assessed by the detection of choline acetyltransferase (ChAT), acetylcholinesterase (AChE) and acetylcholine (ACh) levels in serum. Compared with children in the first quartile, those in fourth quartile the risk of either developing DF or IQ < 120 increased by 19% and 20% for water and urinary fluoride. The risk of having both increased by 58% and 62% in third and fourth quartile for water fluoride, 52% and 65% for urinary fluoride. Water fluoride concentrations were positively associated with AChE and negatively associated with ChAT and ACh, trends were same for urinary fluoride except for ACh. The risk of either developing DF or having non-high intelligence rose by 22% (95%CI: 1.07%, 1.38%) for the fourth quartile than those in the first quartile of AChE, for having the both, the risk was 1.27 (95%CI: 1.07, 1.50), 1.37 (95%CI: 1.17, 1.62) and 1.44 (95%CI: 1.23, 1.68) in second, third and fourth quartiles. The mediation proportion by AChE between water fluoride and either developing DF or IQ < 120 was 15.7%. For both to exist, the proportion was 6.7% and 7.2% for water and urinary fluoride. Our findings suggest low-to-moderate fluoride exposure was associated with dysfunction of cholinergic system for children. AChE may partly mediate the prevalence of DF and lower probability of having superior and above intelligence.

Effects of SNPs in SOD2 and SOD3 interacted with fluoride exposure on the susceptibility of dental fluorosis

A total of 649 children aged 7-13 years of age were recruited in a cross-sectional study in Tongxu County, China (2017) to assess the effects of interaction between single nucleotide polymorphisms (SNPs) in SOD2 and SOD3 gene and fluoride exposure on dental fluorosis (DF) status. Associations between biomarkers and DF status were evaluated. Logistic regression suggested that the risk of DF in children with rs10370 GG genotype and rs5746136 TT genotype was 1.89-fold and 1.72-fold than that in children with TT/CC genotype, respectively. Increased T-SOD activity was associated with a lower risk of DF (OR = 0.99). The rs2855262*rs10370*UF model was regarded as the optimal interaction model in generalized multifactor dimensionality reduction analyses. Our findings suggested that rs4880 and rs10370 might be useful genetic markers for DF, and there might be interactions among rs10370 in SOD2, rs2855262 in SOD3, and fluoride exposure on DF status.

Comparison of oral health indicators between two places of endemic dental fluorosis in Jordan

INTRODUCTION

Excessive fluoride intake during tooth development causes dental fluorosis.

AIM

This study aimed to (1) determine the prevalence of dental fluorosis in association with fluoride concentrations in drinking water, (2) explore the effects of altitude on the severity of fluorosis in two towns with high fluoride levels in the drinking water, and (3) assess decayed, missing, and filled teeth (DMFT) and oral hygiene practices among participants.

MATERIAL AND METHODS

The sample consisted of 100 and 141 schoolchildren, aged 15.3 ± 1.4 and 16.1 ± 1.3 years, living in Ruwaished and Kuraymah, respectively. Oral examinations were carried out, and dental fluorosis was assessed using the Dean's index. The DMFT index was also used for assessment. Samples of drinking water were analyzed using a fluoride-ion selective electrode. SPSS was used to analyze the data.

RESULTS

Two-thirds (68.8%) of adults from Kuraymah had moderate to severe fluorosis, with only 7% being unaffected. In Ruwaished, 50% of the sample had severe fluorosis, 22% showed moderate fluorosis, and none were unaffected. The average DMFT scores were 3.18 ± 1.81 and 3.81 ± 1.41 for Kuraymah and Ruwaished, respectively. In both towns, males had significantly higher caries scores than females. Oral hygiene was poor, as 64% and 57% of the participants from Kuraymah and Ruwaished, respectively, did not brush their teeth. A significant correlation was found between poor oral hygiene and increased DMFT scores.

CONCLUSIONS

This study concluded that higher fluorosis incidence and severity were present in the higher-altitude location (Ruwaished). Moreover, this study also indicated that fluorosed teeth are not immune to caries, and the preventive management of dental fluorosis should be directed to de-fluoridation of drinking water in endemic areas.

Hydrogeogenic fluoride in groundwater and dental fluorosis in Thai agrarian communities: a prevalence survey and case-control study

Background

Dental fluorosis can be a disease of social inequity in access to safe drinking water. This dental public health issue becomes prominent in socially disadvantaged agrarian communities in fluoride endemic areas where the standard irrigation system is unavailable and groundwater containing natural fluoride is the major drinking water source. This study aimed to determine the prevalence and severity of dental fluorosis in children and to evaluate its association with fluoride in groundwater in the aforementioned setting in Thailand.

Methods

A cross-sectional survey of 289 children in Nakhon Pathom Province was conducted in 2015. Children with very mild to severe fluorosis were regarded as ‘cases’ while their counterparts were ‘controls’ for a subsequent case–control study. Records of fluoride concentrations in groundwater used for household supply corresponding to resident and number of years by age of each child during 2008–2015 were retrieved. Other exposure variables were measured using a questionnaire. Prevalence ratio (PR), a measure indicating the relative effect of different levels of fluoride on dental fluorosis, was obtained from Poisson regression with robust standard error.

Result

There were 157 children with very mild to moderate dental fluorosis (54.3% prevalence). The univariable analysis revealed that the prevalence of dental fluorosis among children with fluoride concentrations in water sources of 0.7–1.49 (index category 1) and ≥ 1.5 ppm (index category 2) was 1.62 (95% CI; 0.78, 3.34) and 2.75 (95% CI; 1.42, 5.31) times the prevalence among those with fluoride < 0.7 ppm (referent category). After adjusting for all covariates, the adjusted prevalence ratios in both index categories were 1.64 (95% CI; 0.24, 11.24) and 2.85 (95% CI; 0.44, 18.52) which were close to their corresponding crude estimates. Since the magnitude of confounding, measured by (PR_crude–PR_adjusted)/PR_adjusted, were less than 10% for both index categories; this indicated the limited confounding effect of all covariates.

Conclusions

In fluoride endemic areas, groundwater containing natural fluoride utilized for household consumption resulted in high dental fluorosis prevalence, particularly in the groundwater with fluoride concentrations of ≥ 1.5 ppm.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01902-8.

Dental Fluorosis and Periodontium: an Original Research Report of In Vitro and In Vivo Institutional Studies

Fluorosis is one of the global problems that have persisted for a very long time now without any specific treatment and cure. Fluoride is known for its influence on the tooth structures like enamel and dentin, but little information exists on its effect on the surrounding periodontal structures and bone. With this background, we conducted multiple studies assessing etiological, diagnostic, therapeutic and clinical criteria in subjects with and without dental fluorosis in a single group of the population residing in high fluoride water areas (1.5-3.0 ppm) of Davangere District, Karnataka, India. These preliminary studies conducted are hereby elaborately presented and discussed in this comprehensive review article along with their important conclusions.

children and adolescents, NHANES 2015-2016

Drinking water fluoridation was a mid-twentieth century innovation based on the medical hypothesis that consuming low doses of fluoride at the teeth forming years provided protection against dental decays. Numerous studies showed that high level exposure to fluoride could cause dental and skeleton fluorosis. However, there was limited study focusing on the fluorosis effect of low levels of exposure to fluoride. Therefore, our study aimed to examine whether the low level of fluoride exposure (measured in blood plasma and household tap water) was associated with the risk of dental fluorosis based on data of the National Health and Nutrition Examination Survey (NHANES) 2015-2016. We analyzed data in 2098 children and adolescents who had Dean's Index scores, and water and plasma fluoride measures. The Dean's Index score was measured by calibrated dental examiners using the modified Dean's fluorosis classification system. Fluoride was measured in plasma and household tap water. In this study, we found that the rate of fluoride concentration in water above the recommended level of 0.7 mg/L was 25%, but the prevalence of dental fluorosis was 70%. Binary logistic regression adjusted for covariates showed that higher water fluoride concentrations (0.31-0.50, 0.51-0.70, > 0.70 compared 0.00-0.30) were associated with higher odds of dental fluorosis (OR = 1.48, 95% CI: 1.13-1.96, p = 0.005; OR = 1.92, 95% CI: 1.44-2.58, p < 0.001, and OR = 2.30, 95% CI: 1.75-3.07, p < 0.001, respectively). The pattern of regression between plasma fluoride and dental fluorosis was similar. Inclusion, our study showed that even low level of water or plasma fluoride exposure was associated with increased the risk of dental fluorosis. The safety of public health approach of drinking water fluoridation for global dental caries reduction are urgently needed further research.

Hydrogeochemistry and health hazards of fluoride-enriched groundwater in the Tarim Basin, China

Fluoride (F^-) enrichment reduces the availability of groundwater resources in the arid region, and it is thus important to investigate the hydrogeochemistry and health hazards of fluoride-enriched groundwater. Seventy-two groundwater samples (20 unconfined samples from the piedmont plain, 22 unconfined samples and 30 shallow confined samples from the alluvial plain) were collected in the Tarim Basin of China to illustrate the geochemical processes driving the F^- enrichment and the incidence of dental fluorosis. The patterns of average ions contents in groundwater are Na⁺ > Ca²⁺ > Mg²⁺ > K⁺ and SO₄^2- > Cl^- > HCO₃^- > NO₃^- > F^-. The highest F^- concentration (average 2.16 mg/L) is observed in unconfined groundwater in the alluvial plain, while the lowest (average 0.63 mg/L) is recorded in unconfined groundwater in the piedmont plain. Approximately 5.0% of unconfined groundwater in the piedmont plain, 90.9% of unconfined groundwater and 33.3% of shallow confined groundwater in the alluvial plain contain F^- concentrations exceeding 1.0 mg/L (Chinese drinking water standard). Mineral dissolution, cation exchange, and evaporation play a significant role in the formation of solutes in groundwater. High-F^- groundwater is mostly associated with SO₄·Cl-Na·Ca, SO₄·Cl-Na·Mg, and SO₄·Cl-Na types water. Thermodynamic simulations reveal that the dissolution of F-bearing minerals (e.g., fluorite) significantly controls the F^- contents in groundwater. High concentrations of F^- are closely related to high HCO₃^-, high Na⁺, high salinity, cation exchange, and evaporation. This demonstrates that high F^- concentrations are caused by the increase in fluorite solubility due to high ionic strength, Ca²⁺ consumption and the desorption of F^- from solid surfaces under alkaline conditions. Mixing with the upper unconfined groundwater plays a vital role in the enrichment of F^- in shallow confined groundwater in the alluvial plain. The health risk assessment based on Dean's classification indicates that the percentage prevalence of fluorosis for boys aged 6 to 18 is 15.5% for Yecheng (YC), 18.4% for Zepu (ZP), 33.3% for Shache (SC), 29.8% for Maigaiti (MG), and 44.9% for Bachu (BC), while that for girls of the same age is 14.3% for YC, 24.3% for ZP, 42.2% for SC, 41.4% for MG, and 45.3% for BC. For male and female adults aged between 19 and 68, the percentage prevalence of fluorosis is: YC (11.5%, 12.0%), ZP (18.3%, 20.0%), SC (35.4%, 35.0%), MG (32.5%, 39.7%), and BC (42.4%, 44.3%). It is obvious that younger generation, especially girls, suffers from more severe dental fluorosis. This study has implications for the effective management of high-F^- groundwater in arid regions.

Calcium and Vitamin D Supplementation Effectively Alleviates Dental and Skeletal Fluorosis and Retain Elemental Homeostasis in Mice

Fluoride (F) is an essential trace element, but chronic exposure beyond the permissible limit (1.5 ppm) effectuates dental and skeletal fluorosis. Although 200 million people across the world are suffering from toxic manifestations of F, till now proper treatment is not available. In this study, we assessed the effectiveness of calcium and vitamin D supplementation for alleviation of fluorosis. Swiss albino mice were divided into 6 groups; group I-control group (received drinking water ˂ 0.5 ppm F; within the permissible limit), group II-treated with 15 ppm of sodium fluoride (NaF) for 4 months, group III-treated with 15 ppm of NaF for 8 months through drinking water. Group IV-orally treated with 15 ppm NaF for 4 months, thereafter received only drinking water for next 4 months, group V-orally treated with 15 ppm NaF for 4 months, thereafter received drinking water supplemented with calcium and vitamin D (2.5-g calcium kg^-1 diet and 1000 IU vitamin D kg^-1 diet) for next 4 months, and group VI was treated with 15 ppm of NaF through drinking water as well as supplemented with calcium and vitamin D for 4 months. NaF treatment caused dental fluorosis, skeletal fluorosis, and alteration of bone's metal profile. Substitution of NaF-containing water with normal drinking water reduced the severity of fluorosis but supplementation of calcium and vitamin D effectively alleviated dental and skeletal fluorosis, reduced F deposition, and retained elemental homeostasis of the bone. Our findings strongly support that calcium and vitamin D act as redeemer of fluorosis. Graphical Abstract.

Clinical changes in the severity of dental fluorosis: a longitudinal evaluation

BACKGROUND

Dental fluorosis (DF) has been one of the most prevalent pediatric dental conditions associated with aesthetic concern and treatment needs. This study aimed to identify the longitudinal clinical change in the severity of DF in 8-12-year-old children and its association with gender, age, severity, and tooth type.

METHODS

This observational study assessed the dental aspects of the 92 Colombian children in 2015 (mean age at beginning 9.71 years ± 1.23) and 2018 (mean age 13.69 years ± 1.41), from an area with high DF prevalence. DF was recorded in all permanent teeth by two calibrated examiners using the Thylstrup and Fejerskov Index (TFI). DF severity change (maximum-TFI-score) was analyzed with descriptive analysis at the tooth level. Associated factors were evaluated with the generalized linear model, binomial family, and logarithmic link function.

RESULTS

TFI scores ranged between 1 (very mild) to 6 (severe), being score 2 (41.7%) the most prevalent. After three years, 29.6% of the teeth presented score reduction, 24.1%, increased and 46.3% did not change; the significant association was related to increasing of the basal TFI = 1 score (44.2%) (RR = 9.7; 95% CI 1.7-56.5; p = 0.01) and with canines, premolars and second-permanent-molars teeth group (RR = 3.3; 95% CI 1.9-5.6; p = 0.005).

CONCLUSION

The present study based on clinical features about DF confirms the dynamic post-eruptive nature of this condition. After three years of follow-up, a considerable proportion of the teeth changed to a higher score. Furthermore, the canines, premolars, and second-permanent-molars showed a higher incidence of an increase in severity of TFI score.

Prevalence of dental fluorosis and treatment needs among 11-14 years old school children in endemic fluoride areas of Haryana, India

Introduction

Dental fluorosis is a major endemic oral disease characterized by hypo mineralization of enamel caused due to consumption of water containing high concentration of fluoride during developmental stages of teeth.

Aim

To assess the prevalence of dental fluorosis among 11-14 years old school children in endemic fluoride areas of Haryana and to find their treatment needs.

Materials and Methods

A cross-sectional study was conducted among 2200 school children in endemic fluoride areas of Haryana (India) for a period of six months. Dental fluorosis was recorded by the Thylstrup-Fejerskov index (TF index) given by Thylstrup A, Fejerskov O.

Statistical Analysis

Data entry and analysis were performed using Statistical Package of Social Sciences (SPSS) software version 18.0. Chi square test was used to find association between TFI scores and gender, age categories. The level of significance was set at 0.05.

Results

Prevalence of dental fluorosis (TFI) reached 96.6% with most children falling in TFI score 2, 3, 4 and 5 categories. Mean TFI score of study population was found to be 3.19 ± 1.551. There was significant difference found between gender and prevalence of dental fluorosis (P = 0.00).

Conclusion

Our findings showed the increased prevalence of dental fluorosis in endemic fluoride areas with mild to moderate level of dental fluorosis.

Resin infiltration and remineralization interventions in management of moderate dental fluorosis: A quantitative light-induced fluorescence-based randomized controlled trial

Context

Aesthetic concerns due to dental fluorosis (DF) considerably impact pyschosocial health in young children and requires aesthetic microinvasive treatment.

Aims

The aim of this study was to use quantitative light-induced fluorescence to evaluate two intervention protocols: microabrasion with resin infiltration and microabrasion with remineralization and assess which brings about more fluorescence gain; better colour masking and greater patient satisfaction among subjects with dental fluorosis.

Methods and Material

120 maxillary central incisors with Grade 3 DF (Dean's Fluorosis Index) were randomly distributed into four groups: I-microabrasion + resin infiltration (fluorosis with stains); II microabrasion + remineralization (fluorosis with stains); III-microabrasion + resin infiltration (fluorosis without stains); IV microabrasion + remineralization (fluorosis without stains). At baseline, post-microabrasion and post-intervention Quantitative light-induced fluorescent images were captured. Fluorescence gain (ΔF) was analysed from the blue light images. The white light images were used to evaluate post intervention colour difference (ΔE = [(ΔL*) 2+(Δa*) 2+(Δb*) 2]1/2) and child satisfaction was evaluated.

Statistical Analysis Used

Collected data was analysed using repeated measures ANOVA and Independent t-test.

Results

Intra-group comparison of ΔF values showed statistically significant improvement in ΔF value in all the four groups (P < 0.001, 0.002). Inter-group comparison of ΔF values based on intervention showed statistically significant fluorescence gain (P < 0.004) indicating resin infiltration intervention being better than remineralization in unstained grade III fluorosis. The colour difference was statistically significantly better with resin infiltration in both stained and unstained Grade III DF (P < 0.001).

Conclusions

Resin infiltration intervention showed better fluorescence gain and colour masking compared to remineralization intervention.