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

Author(s):  
Yuhui Du ◽  
Xiaoli Fu ◽  
Jing Jin ◽  
Zhiyuan Li ◽  
Kaihong Xu ◽  
...  
2010 ◽  
Vol 21 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Danilo Bonadia Catani ◽  
Livia Maria Andaló Tenuta ◽  
Fernanda Alcântara Andaló ◽  
Jaime Aparecido Cury

Considering that blood fluoride concentration varies according to fluoride exposure and that dental fluorosis is related to the amount of enamel formed under a given fluoride dose, the present study investigated whether the fluorosis produced by an oscillating chronic fluoride dose would be similar to that caused by exposure to a constant dose, representing the mean of the oscillation during a given time. Rats received during 78 days water with fluoride concentrations of 0, 12.5, 25 or 37.5 µg F/mL, or oscillating concentrations of 12.5 and 37.5 µg F/mL every 72 h (mean exposure=25 µg F/mL). The concentrations of fluoride in the plasma, femur and incisors of the rats were determined at the end of the experimental period. Also, the enamel dental fluorosis index was determined in the incisors using a quantitative method developed by our research group named Dental Fluorosis by Image Analysis (DFIA). Fluoride concentrations in plasma, femur and teeth, and DFIA increased linearly for constant fluoride concentrations in water (p<0.0001, r values=0.87-0.98). The results of the oscillating group and the groups receiving 25 µg F/mL did not differ significantly (p>0.05). The findings of this study suggest that in animals chronically exposed to symmetrically oscillating fluoride doses, the resulting dental fluorosis reflects the metabolic effect of the mean of the oscillating doses.


Author(s):  
Yumin Wang ◽  
Ran Yu ◽  
Guangcan Zhu

In this study, the concentration of fluoride and the associated health risks for infants, children, and adults were analyzed and compared for three drinking water sources in Yancheng City, Jiangsu Province, China. To analyze the relationship between the water quality parameters of pH, fluoride (F−), sulfate (SO42−), chloride (Cl−), total dissolved solids (TDS), total alkalinity (TAlk), sodium (Na+), and potassium (K+), statistical analyses including correlation analysis, R-mode cluster analysis and factor analysis were performed based on monthly data from the year 2010 to 2015. The results indicated: (1) Fluoride concentrations in the drinking water sources ranged from 0.38 to 1.00 mg L−1 (mean = 0.57 mg L−1) following the order of Tongyu River > Yanlong Lake > Mangshe River; (2) fluoride concentrations in 22.93% of the collected samples were lower than 0.5 mg L−1, which has the risk of tooth cavities, especially for the Mangshe River; (3) the fluoride exposure levels of infants were higher than children and adults, and 3.2% of the fluoride exposure levels of infants were higher than the recommended toxicity reference value of 122 μg kg−1 d−1 as referenced by Health Canada, which might cause dental fluorosis issues; (4) the physico-chemical characteristics are classified the into four groups reflecting F−- TAlk, Na+-K+, SO42−-Cl−, and pH-TDS, respectively, indicating that fluoride solubility in drinking water is TAlk dependent, which is also verified by R-mode cluster analysis and factor analysis. The results obtained supply useful information for the health department in Yancheng City, encouraging them to pay more attention to fluoride concentration and TAlk in drinking water sources.


2020 ◽  
Vol 54 (2) ◽  
pp. 134-143
Author(s):  
Oladipo S. Idowu ◽  
Ralph M. Duckworth ◽  
Ruth A. Valentine ◽  
Fatemeh Vida Zohoori

Due to practical difficulties in quantifying fluoride exposure, the ability of various biomarkers to predict exposure has been investigated previously. However, the results are inadequate for validation of their application and usefulness. This study aimed to investigate the association between contemporary/recent biomarkers of fluoride exposure and total daily fluoride intake (TDFI) of children with large differences in fluoride exposure through drinking water. TDFI was assessed in 61 healthy 4- to 5-year-old children who provided at least 1 biomarker sample; 32 lived in a low-fluoride area (0.04 mg F/L) and 29 lived in a high-fluoride area (3.05 mg F/L). Validated questionnaires were administered to evaluate fluoride intake from diets (including water) and toothpaste ingestion. Daily urinary fluoride excretion (UFE) and fluoride concentrations in plasma, fasting whole saliva, hair, and nails (toenails/fingernails) were evaluated and related to total fluoride exposure. TDFI, UFE, and fluoride concentrations of biomarkers were statistically significantly higher in the high-fluoride area than in the low-fluoride area. There was a strong statistically significant positive correlation between TDFI and UFE (ρ = 0.756, p < 0.001); plasma fluoride concentration (ρ = 0.770, p < 0.001); and toenail fluoride concentration (ρ = 0.604, p < 0.001). The statistically significant positive correlation between TDFI and fingernail fluoride concentration (ρ = 470, p < 0.001) as well as between TDFI and fasting whole saliva fluoride concentration (ρ = 0.453, p = 0.001) was moderate, whereas it was weak between TDFI and hair fluoride concentration (ρ = 0.306, p = 0.027). In conclusion, the current study confirmed the suitability of 24-h urine samples for estimating fluoride exposure in children. The strong correlations between TDFI and fluoride in plasma and toenails also suggest these biomarkers may be considered for health risk assessments of fluoride in children who are susceptible to development of dental fluorosis.


2007 ◽  
Vol 86 (8) ◽  
pp. 723-728 ◽  
Author(s):  
L.G. Do ◽  
A.J. Spencer

This study aimed to evaluate the risk-benefit balance of several fluoride exposures. Fluoride exposure history of randomly selected children was collected for calculation of exposure to fluoridated water, toothpaste, and other fluoride sources. We evaluated the risk-benefit balance of fluoride exposure by comparing dental fluorosis on maxillary central incisors, recorded at the time of the study with the use of the Thylstrup and Fejerskov Index, and deciduous caries experience, recorded at age six years, of the same group of South Australian children who were from 8 to 13 years old in 2002–03. Population Attributable Risk for fluorosis and Population Prevented Fraction for caries were estimated. Fluorosis prevalence was found to be 11.3%; caries prevalence, 32.3%; mean dmfs, 1.57 (SD 3.3). Exposure to fluoridated water was positively associated with fluorosis, but was negatively associated with caries. Using 1000-ppm-F toothpaste (compared with 400- to 550-ppm-F toothpaste) and eating/licking toothpaste were associated with higher risk of fluorosis without additional benefit in caries protection. Evaluation of the risk-benefit balance of fluoride exposure provides evidence to assist in the formulation of appropriate guidelines for fluoride use.


2014 ◽  
Vol 496 ◽  
pp. 188-197 ◽  
Author(s):  
Tewodros Rango ◽  
Avner Vengosh ◽  
Marc Jeuland ◽  
Redda Tekle-Haimanot ◽  
Erika Weinthal ◽  
...  

Author(s):  
Paulina Farías ◽  
Jesús Alejandro Estevez-García ◽  
Erika Noelia Onofre-Pardo ◽  
María Luisa Pérez-Humara ◽  
Elodia Rojas-Lima ◽  
...  

Water fluoride levels above the World Health Organization’s guideline (1.5 mg/L), common in overexploited aquifers, represent a health hazard. Our objective was to assess the health risks posed by exposure to fluoride in different drinking water sources in a contaminated basin in Mexico. Fluoride was measured in mutual drinking water sources and in the urine of 39 children and women. Risks were estimated through hazard quotient (HQ) by drinking water source. Dental fluorosis was assessed in the children. Mean fluoride water concentrations (mg/L) were: well, 4.2; waterhole, 2.7; bottled, 2.1; rainwater, 0.4. The mean urinary fluoride concentrations (specific gravity adjusted) were 2.1 mg/L and 3.2 mg/L in children and women, respectively. Our multiple linear regression model showed children’s urinary fluoride concentrations increased 0.96 mg/L for every 1 mg/L increase in water fluoride (p < 0.001). Dental fluorosis was diagnosed in 82% of the children, and their HQ according to drinking water source was: well, 1.5; waterhole, 1.1; bottled, 0.8; harvested rainwater, 0.3. The pervasive dental fluorosis indicates a toxic past fluoride exposure; urinary fluoride levels and HQs indicate high exposure and current health risks for most children. Drinking harvested rainwater will likely prevent most of the local fluoride exposure.


1994 ◽  
Vol 8 (1) ◽  
pp. 105-110 ◽  
Author(s):  
P.K. Den Besten

Several epidemiological studies, beginning with those of Dean and co-workers in the 1940's, clearly demonstrate the relationship between dental fluorosis in humans and the level of fluoride in water supplies. These studies and others have shown that, in a population, there is a direct relationship among the degree of enamel fluorosis, plasma and bone fluoride levels, and the concentration of fluoride in drinking water. However, dental fluorosis is a reflection of fluoride exposure only during the time of enamel formation, somewhat limiting its use as a biomarker. In addition, the degree of fluorosis is dependent not only on the total fluoride dose, but also on the timing and duration of fluoride exposure. At the level of an individual response to fluoride exposure, factors such as body weight, activity level, nutritional factors, and the rate of skeletal growth and remodeling are also important. These variables, along with an individual variability in response to similar doses of fluoride, indicate that enamel fluorosis cannot be used as a biological marker of the level of fluoride exposure for an individual.


1994 ◽  
Vol 8 (1) ◽  
pp. 56-65 ◽  
Author(s):  
A. Kingman

The currently popular scoring systems used to diagnosis fluorosis use different measurement units, evaluate variable numbers of sites per person, and involve non-comparable groupings of clinical symptoms. Although none of these factors is related to the level of fluoride exposure in the examined population, their combined effect produces fluorosis prevalence values for a population which vary considerably among and within these scoring systems. Intrinsic factors for a scoring system include the inclusion of a questionable category, the minimal level of fluorotic involvement, and the number of affected sites within a subject required for case definition. Thus, a case definition of fluorosis for each scoring system, although not mandatory, would certainly be desirable so that dental epidemiologists and clinical investigators can interpret fluorosis scores relative to risk assessment. On the other hand, ratios of fluorosis prevalence magnitudes, as evidenced by odds ratios, can be more stable between scoring systems when groups with different fluoride exposure levels are compared. There is a strong correlation between extent and specific measures of fluorosis severity for Dean's Index (DI) and the Tooth Surface Index of Fluorosis (TSIF) scoring system, as well as within each scoring system separately. Parallel patterns in fluorosis severity were found among groups with different fluoride exposures for the DI and TSIF scoring systems. The effects of fluoride exposure on severity levels of fluorosis may be better understood by using relative measures rather than by using differences in severity levels.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Lizet Jarquín-Yañez ◽  
José de Jesús Mejía-Saavedra ◽  
Nelly Molina-Frechero ◽  
Enrique Gaona ◽  
Diana Olivia Rocha-Amador ◽  
...  

Objective. The aim of this study is to investigate urine fluoride concentration as a toxicity factor in a rural community in the state of San Luis Potosi, Mexico.Materials and Methods. A sample of 111 children exposed to high concentrations of fluoride in drinking water (4.13 mg/L) was evaluated. Fluoride exposure was determined by measuring urine fluoride concentration using the potentiometric method with an ion selective electrode. The diagnosis of dental fluorosis was performed by clinical examination, and the severity of damage was determined using Dean’s index and the Thylstrup-Fejerskov (TF) index.Results. The range of exposure in the study population, evaluated through the fluoride content in urine, was 1.1 to 5.9 mg/L, with a mean of 3.14 ± 1.09 mg/L. Dental fluorosis was present in all subjects, of which 95% had severe cases. Higher urine fluoride levels and greater degrees of severity occurred in older children.Conclusions. The results show that dental fluorosis was determined by the presence of fluoride exposure finding a high positive correlation between the severity of fluorosis and urine fluoride concentration and the years of exposure suggested a cumulative effect.


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