Risk factors associated with dental fluorosis in Central Plateau State, Nigeria

Fluorosilicic acid and cotinine, separately and in combination, induce genotoxicity and telomeric reduction in human osteoblast cell line MG63

Skeletal fluorosis is a severe case in which bone deformations and bone tissue weakening occur due to excessive fluorine deposition. Recently, data on smoking have been published that smoke constituents can indirectly influence bone mass and interfere in the metabolism of fluorides in humans. Thus, the present in vitro study aimed to assess the genetic instability in human osteoblast MG63 cells exposed to fluorosilicic acid (FA) and cotinine (COT), separately and in combination, in concentrations found in human plasma. For this, cell cytotoxicity was performed by MTT assay; DNA damage was performed by alkaline comet assay (CA), modified by repair endonucleases (+FPG); micronuclei test (MN) using CBMN-Cyt assay; and telomere length (TL) by qPCR in MG63 cells. No cytotoxicity was observed for all concentrations tested in this study. Alkaline CA results showed a significant increase in DNA damage at all FA concentrations (0.03125-0.300 mg/L), in the two highest concentrations of COT (125 and 250 ng/mL), and the highest concentration of FA+COT (0.300 mg/L+250 ng/mL). Alkaline CA+FPG test was used to detect oxidized nucleobases, which occurred at the two highest concentrations of FA, COT, and FA+COT. Micronuclei test showed an increase in the frequency of MN at all concentrations of FA (0.075-0.300 mg/L) except in the lowest concentration (0.03125 mg/L), in the two highest concentrations of COT (125 and 250 ng/mL), and all concentrations of FA+COT. There was no significant difference in nuclear division index, binucleated cells, nucleoplasmic bridge, and nuclear bud. A TL reduction was observed in cells treated with the highest concentrations of FA alone (0.300 mg/L) and FA+COT (0.300 mg/L+250 ng/mL). Finally, our study showed that FA and COT (mainly alone) at concentrations found in human plasma induced oxidative damage and genetic instability in human osteoblast cells.

Association Between Dietary Fluoride and Calcium Intake of School-Age Children With Symptoms of Dental and Skeletal Fluorosis in Halaba, Southern Ethiopia

Background

In the Ethiopian Rift Valley, ways to reduce the fluoride (F) burden from drinking water have been unsuccessful. Calcium (Ca) intake may mitigate fluorosis by binding with F ions and preventing absorption. The purpose of this study was to examine the association between Ca intake and proportion of fluorosis symptoms in school-age children in an area where F levels are known to be higher than WHO limit of 1.5 mg F/L water.

Methods

A cross-sectional survey in the Halaba zone involved 135 eligible children aged 6–13 year who were recruited to have dental fluorosis assessed by a dentist and skeletal fluorosis assessed by a physiotherapist. Dietary Ca intake was determined by 24-h recall. Food items and samples from ground wells, taps and spring water were collected for F concentration. Associations were measured using bivariate logistic regression, adjusted for known confounders.

Results

Water F averaged 5.09 mg/L. Total F intake was high, 10.57 mg/day, and Ca intake was low, 520 mg/day. Prevalence of dental fluorosis (from very mild to severe symptoms) was 73.1% for younger children (6–8 years) and 68.3 % for older children (9–13 years). The prevalence of children having symptoms of skeletal fluorosis ranged between 55.1 and 72.4%, with no apparent age difference. Dietary F intake of children was significantly positively associated with presence of dental fluorosis. Dietary Ca intake of children was significantly negatively associated with dental fluorosis. Higher than average dietary F intake significantly increased the odds of developing skeletal fluorosis symptoms when measured as inability to stretch and fold arms to touch back of head. Higher than average Ca intake was significantly associated with decreased odds of developing skeletal fluorosis measured as inability to bend body to touch the toes or floor.

Conclusions

High dietary F, as expected, was associated with fluorosis in children. In the presence of higher Ca intake (>520 mg/day) some fluorosis symptoms were mitigated. There is a need to improve Ca intakes as all were below recommended levels, and this nutritional strategy may also reduce burden of excess F.

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.

Meta-analysis and risk assessment of fluoride contamination in groundwater

This study aimed to carry out a systematic review of meta-analysis and risk assessment of the global pooled concentration of fluoride and identify the influencing factors of fluoride loads in groundwater. The study extracted data from 36 most prevalent regions of 20 countries in the world through various search engines using keywords as well as Boolean operators and follows the PRISMA statement in every phase of literature searching. The study illustrated the pooled concentration of fluoride in the selected 20 countries was 2.1267 mg/L (1.650, 2.604) at 95% confidence interval, which was higher than the WHO standards limit of 1.5 mg/L. The results of the meta-analysis suggested that pH, Na, HCO₃ and rainfall was significantly positively correlated (r = ~0.4; p ˂ 0.05) to fluoride and has a weak correction with the other parameters such as local temperature, altitude, water depth, EC, Ca, and Mg (r = -0.064 to +0.214; p ˂ 0.05). Concerning, the risk assessment through oral and dermal route exposure revealed that the consumers in most of the regions were at considerable risk, and the children were more vulnerable than the adults (THQ > 1). The study findings would help to take measures for safe water supply in the affected areas. PRACTITIONER POINTS: The calculated pooled concentration of fluoride was 2.1267 mg/L (1.650, 2.604) at 95% CI in groundwater of the study areas. Climatic conditions and lithological composition are the key controlling factors for groundwater fluoride contamination. Semi-arid and arid regions are significantly affected by fluoride rather than humid areas. Regarding fluorosis in selected regions, children (78%) are more vulnerable than adults (23%).

Factors influencing the relationship between fluoride in drinking water and dental fluorosis: a ten-year systematic review and meta-analysis

The relationship between naturally fluoridated groundwater and dental fluorosis has received large attention from researchers around the world. Despite recognition that several factors influence this relationship, there is a lack of systematic studies analyzing the heterogeneity of these results. To fill such a gap, this study performs a systematic review and meta-analysis to understand which factors influence this relationship and how. Selected studies were sampled between 2007 and 2017 from Web of Science, PubMed, Google Scholar and Scopus using keywords and Boolean operators. Results of the systematic review show that dental fluorosis affects individuals of all ages, with the highest prevalence below 11, while the impact of other factors (gender, environmental conditions, diet and dental caries) was inconclusive. Meta-regression analysis, based on information collected through systematic review, indicates that both fluoride in drinking water and temperature influence dental fluorosis significantly and that these studies might be affected by publication bias. Findings show that fluoride negatively affects people's health in less developed countries. The conclusions discuss policy tools and technological innovations that could reduce fluoride levels below that of the World Health Organization (WHO) (<1.5 mg/L).

Prevalence, severity, and request for treatment of dental fluorosis among adults in an endemic region of Northern Nigeria

Objectives:

The objective was to assess the prevalence of all forms of dental fluorosis (DF), the severity, and the request for treatment as a measure of the burden of the condition among adult patients seen at a tertiary health facility in an endemic region of Northeastern Nigeria.

Materials and Methods:

This was a cross-sectional study that collected required information using a questionnaire from adult dental patients followed by dental examination to assess for DF.

Statistical Analysis Used:

Associations between sociodemographic distributions (age and gender) and prevalence were analyzed on the Statistical Package for the Social Sciences using the Chi-square test. Analysis was done at 95% confidence interval and the level of statistical significance was set at P < 0.05.

Results:

Three hundred and twelve patients (41.7%) were diagnosed with DF among the patients who resided in the endemic region with a calculated Community Fluorosis Index of 0.62. The mean age of the affected patients was 33.8 ± 9.2 years, with a majority of the patients in the 16–25 (47.4%) years' age group and a preponderance among females (P = 0.003). A greater proportion of the 312 diagnosed patients, 201 (64.3%), had fluorosis of esthetic concern, while only 9.3% sought treatment. Most of these patients that sought treatment had the severe form of the enamel defect.

Conclusions:

DF should be considered as a condition of public health importance in this region. It is necessary to conduct a community-based study and fluoride mapping of the northeastern region as well to determine other factors that may contribute to its occurrence in this population.

Protective effects of melatonin against fluoride-induced oxidative stress in rats at high altitude

This study was conducted to evaluate the protective effects of melatonin against fluoride-induced oxidative stress-mediated haematological and biochemical changes in rat at high altitude. Adult male Wistar rats (6) were given the basal diet and drinking water ad lib. for first 7-days which was considered as the control period. Thereafter, they were exposed to NaF (@ 50 ppm) per-oral through drinking water for the next 14 days followed by melatonin treatment (@ 15 mg/kg BW, p.o.) for the next 14 days. The result showed induction of oxidative stress during NaF treatment alone, which caused significant increase in alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) activity, and % inhibition of DPPH, MDA, and water intake. Whereas, total antioxidant capacity (FRAP) and body weight gain were significantly reduced during NaF exposure. Haemogram analysis indicated significant decrease in haemoglobin, packed cell volume, erythrocytes, lymphocytes, platelets count, whereas increase in MCH, monocytes, neutrophil, and eosinophil during NaF exposure. However, melatonin administration after 14 days of fluoride treatment resulted in significant amelioration of adverse changes occurred in different blood-biochemical parameters and also increased the total antioxidant status. Notably, the body weight gain improved during melatonin administration. These findings indicated induction of oxidative stress-mediated adverse change in haematology and biochemical parameters, and amelioration effect of oral dose of melatonin in rats under high altitude stress condition. Hence it can be concluded that melatonin acts as a potent antioxidant agent, which may be orally supplemented for amelioration of fluoride-mediated oxidative stress even under prevalent high altitude stress.

Prevalence and extent of enamel defects in the permanent teeth of 8-year-old Nigerian children

OBJECTIVES

Enamel formation is a vulnerable developmental process, susceptible to environmental influences such as excessive systemic fluoride (F) exposure and infant/childhood disease. This study determined prevalence and extent of developmental enamel defects (DDE) and dental fluorosis in 8-year-old Nigerians and explored associations with key predictors.

METHODS

A sample of 322 healthy 8-year-olds (155 males, 167 females) from primary schools in lower and higher water F areas of (i) rural and (ii) urban parts of Oyo State in south-west Nigeria (n = 4 areas) (in which the mean (SD) F concentration of community water supplies ranged from 0.07 (0.02) to 2.13 (0.64) mg F/L) were dentally examined using modified DDE (mDDE) and Thylstrup and Fejerskov (TF) indices. Drinking waters, cooking waters and toothpaste samples were analysed for F concentration using a F ion-selective electrode (F-ISE). Information on infant/childhood diseases, infant feeding and tooth cleaning practices was obtained from parents/legal guardians. Data were analysed using ANOVA, chi-square tests, Spearman correlation and binary logistic regression as appropriate.

RESULTS

Mean (SD) F concentration of actual drinking and actual cooking waters consumed by participants was 0.25 (0.20) and 0.24 (0.14) mg F/L respectively in the urban higher F area; 1.11 (1.00) and 1.16 (1.02) mg F/L, respectively in the rural higher F area (P < .05). Overall, mouth prevalence of DDE in the permanent dentition was 61.2% with a mean (SD) of 2.4 (2.2) index teeth affected. Dental fluorosis mouth prevalence was 29.8% with a mean of 2.1 (3.7) teeth affected. Prevalence and extent of DDE and dental fluorosis were greater in higher F than lower water F areas (P < .001). A weak positive correlation was seen between extent of dental fluorosis and drinking water F concentration (ρ = 0.28). The absence of infant/childhood disease was associated with a lower risk of DDE being present (P = .001), with an odds ratio of 0.43 (95% CI = 0.26, 0.71). Gender was a statistically significant (P = .014) predictor for dental fluorosis with females having a higher risk OR 1.94 (95% CI = 1.14, 3.28) of dental fluorosis than males.

CONCLUSIONS

In these Nigerian 8-year-olds (n = 322), mouth prevalence of DDE was 61.2% (mean (SD) teeth affected = 2.4 (2.2)), and a key positive predictor was a history of infant/childhood disease. With 29.8% of these children exhibiting dental fluorosis (mean (SD) teeth affected = 2.1(3.7)), drinking water F concentration was identified as a positive predictor, along with gender, with females more at risk of dental fluorosis than males.

Dietary Fluoride Intake and Associated Skeletal and Dental Fluorosis in School Age Children in Rural Ethiopian Rift Valley

An observational study was conducted to determine dietary fluoride intake, diet, and prevalence of dental and skeletal fluorosis of school age children in three fluorosis endemic districts of the Ethiopian Rift Valley having similar concentrations of fluoride (F) in drinking water (~5 mg F/L). The duplicate plate method was used to collect foods consumed by children over 24 h from 20 households in each community (n = 60) and the foods, along with water and beverages, were analyzed for fluoride (F) content. Prevalence of dental and skeletal fluorosis was determined using presence of clinical symptoms in children (n = 220). Daily dietary fluoride intake was at or above tolerable upper intake level (UL) of 10 mg F/day and the dietary sources (water, prepared food and beverages) all contributed to the daily fluoride burden. Urinary fluoride in children from Fentale and Adamitulu was almost twice (>5 mg/L) the concentration found in urine from children from Alaba, where rain water harvesting was most common. Severe and moderate dental fluorosis was found in Alaba and Adamitulu, the highest severity and prevalence being in the latter district where staple foods were lowest in calcium. Children in all three areas showed evidence of both skeletal and non-skeletal fluorosis. Our data support the hypothesis that intake of calcium rich foods in addition to using rain water for household consumption and preparation of food, may help in reducing risk of fluorosis in Ethiopia, but prospective studies are needed.

Prevalence of Dental Fluorosis and associated Risk Factors in Bagalkot District, Karnataka, India

INTRODUCTION

An earlier epidemiological study by these authors revealed fluorosis at very low levels of fluoride concentrations in drinking water.

AIM

The objective of present study was to investigate risk factors of dental fluorosis in permanent teeth in the villages of northern Karnataka, India.

MATERIALS AND METHODS

The present survey was carried out in three villages of Hungund Taluk, Bagalkot District, Karnataka, India, with the fluoride concentration of 0.136, 0.381, and 1.36 ppm. Children aged between 9 and 15, with permanent teeth, were examined for dental fluorosis using Dean's index, as per WHO criteria. Required relevant information regarding risk factors was obtained through a questionnaire.

STATISTICAL ANALYSIS

Data entry and analysis were performed using SPSS for Windows 16.0. Comparison of means of different indices by the three groups was performed using ANOVA and t-test (p < 0.05). Bivariate analysis was performed to identify significant risk factors that affected prevalence and severity of dental fluorosis. Those variables showing a statistically significant association (p < 0.05) on χ2 were entered into multiple logistic regressions to assess their independent effects.

RESULTS

In this study, we analyzed risk factors for both prevalence and severity of fluorosis. From multiple logistic regression analysis, only fluoride concentration in drinking water was found significant with prevalence of fluorosis and only nutritional status showed significant association with severity of fluorosis.

CONCLUSION

Presence or absence of dental fluorosis in permanent teeth was significantly associated with fluoride concentration in drinking water. Once present, its severity was determined by nutritional status of the children - malnourished children exhibiting severe form of fluorosis.

HOW TO CITE THIS ARTICLE

Mahantesha T, Dixit UB, Nayakar RP, Ashwin D Ramagoni NK, Ellore VPK. Prevalence of Dental Fluorosis and associated Risk Factors in Bagalkot District, Karnataka, India. Int J Clin Pediatr Dent 2016;9(3):256-263.

Prevalence of Brick Tea-Type Fluorosis in the Tibet Autonomous Region

Background

The prevalence of brick tea-type fluorosis is high in Tibet because of the habit of drinking brick tea in this region. Brick tea-type fluorosis has become an urgent public health problem in China.

Methods

A cross-sectional survey was conducted to investigate prevalence of brick tea-type fluorosis in all districts of Tibet using a stratified cluster sampling method. Dental fluorosis in children aged 8–12 years and clinical skeletal fluorosis in adults were diagnosed according to the national criteria. A total of 423 children and 1320 adults participated in the study. Samples of drinking water, brick tea, brick tea infusion (or buttered tea), and urine were collected and measured for fluoride concentrations by the fluoride ion selective electrode method.

Results

The fluoride level in all but one of the brick tea samples was above the national standard. The average daily fluoride intake from drinking brick tea in all seven districts in Tibet was much higher than the national standard. The prevalence of dental fluorosis was 33.57%, and the prevalence of clinical skeletal fluorosis was 46.06%. The average daily fluoride intake from drinking brick tea (r = 0.292, P < 0.05), urine fluoride concentrations in children (r = 0.134, P < 0.05), urine fluoride concentrations in adults (r = 0.162, P < 0.05), and altitude (r = 0.276, P < 0.05) were positively correlated with the prevalence of brick tea-type fluorosis. Herdsmen had the highest fluoride exposure and the most severe skeletal fluorosis.

Conclusions

Brick tea-type fluorosis in Tibet is more serious than in other parts of China. The altitude and occupational factors are important risk factors for brick tea-type fluorosis.

Restoration of Fluorosis Stained Teeth: A Case Study

Dental fluorosis manifests by too much ingestion of fluoride resulting in disturbances in enamel mineralization. The result is intrinsic discolorations in the maxillary and mandibular teeth with a poor esthetic appearance. In challenging cases, an esthetic result may be achieved only by a combination of techniques. This case report demonstrates a combination of modalities used to treat a patient presenting with atypical staining as a result of high-level exposure to ingested fluoride present in the drinking water as a child. Conservative treatment consisted of a combination of in-office bleaching to reduce the discoloration and porcelain veneers to create an esthetic result.

Water fluoridation for the prevention of dental caries

BACKGROUND

Dental caries is a major public health problem in most industrialised countries, affecting 60% to 90% of school children. Community water fluoridation was initiated in the USA in 1945 and is currently practised in about 25 countries around the world; health authorities consider it to be a key strategy for preventing dental caries. Given the continued interest in this topic from health professionals, policy makers and the public, it is important to update and maintain a systematic review that reflects contemporary evidence.

OBJECTIVES

To evaluate the effects of water fluoridation (artificial or natural) on the prevention of dental caries.To evaluate the effects of water fluoridation (artificial or natural) on dental fluorosis.

SEARCH METHODS

We searched the following electronic databases: The Cochrane Oral Health Group's Trials Register (to 19 February 2015); The Cochrane Central Register of Controlled Trials (CENTRAL; Issue 1, 2015); MEDLINE via OVID (1946 to 19 February 2015); EMBASE via OVID (1980 to 19 February 2015); Proquest (to 19 February 2015); Web of Science Conference Proceedings (1990 to 19 February 2015); ZETOC Conference Proceedings (1993 to 19 February 2015). We searched the US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization's WHO International Clinical Trials Registry Platform for ongoing trials. There were no restrictions on language of publication or publication status in the searches of the electronic databases.

SELECTION CRITERIA

For caries data, we included only prospective studies with a concurrent control that compared at least two populations - one receiving fluoridated water and the other non-fluoridated water - with outcome(s) evaluated at at least two points in time. For the assessment of fluorosis, we included any type of study design, with concurrent control, that compared populations exposed to different water fluoride concentrations. We included populations of all ages that received fluoridated water (naturally or artificially fluoridated) or non-fluoridated water.

DATA COLLECTION AND ANALYSIS

We used an adaptation of the Cochrane 'Risk of bias' tool to assess risk of bias in the included studies.We included the following caries indices in the analyses: decayed, missing and filled teeth (dmft (deciduous dentition) and DMFT (permanent dentition)), and proportion caries free in both dentitions. For dmft and DMFT analyses we calculated the difference in mean change scores between the fluoridated and control groups. For the proportion caries free we calculated the difference in the proportion caries free between the fluoridated and control groups.For fluorosis data we calculated the log odds and presented them as probabilities for interpretation.

MAIN RESULTS

A total of 155 studies met the inclusion criteria; 107 studies provided sufficient data for quantitative synthesis.The results from the caries severity data indicate that the initiation of water fluoridation results in reductions in dmft of 1.81 (95% CI 1.31 to 2.31; 9 studies at high risk of bias, 44,268 participants) and in DMFT of 1.16 (95% CI 0.72 to 1.61; 10 studies at high risk of bias, 78,764 participants). This translates to a 35% reduction in dmft and a 26% reduction in DMFT compared to the median control group mean values. There were also increases in the percentage of caries free children of 15% (95% CI 11% to 19%; 10 studies, 39,966 participants) in deciduous dentition and 14% (95% CI 5% to 23%; 8 studies, 53,538 participants) in permanent dentition. The majority of studies (71%) were conducted prior to 1975 and the widespread introduction of the use of fluoride toothpaste.There is insufficient information to determine whether initiation of a water fluoridation programme results in a change in disparities in caries across socioeconomic status (SES) levels.There is insufficient information to determine the effect of stopping water fluoridation programmes on caries levels.No studies that aimed to determine the effectiveness of water fluoridation for preventing caries in adults met the review's inclusion criteria.With regard to dental fluorosis, we estimated that for a fluoride level of 0.7 ppm the percentage of participants with fluorosis of aesthetic concern was approximately 12% (95% CI 8% to 17%; 40 studies, 59,630 participants). This increases to 40% (95% CI 35% to 44%) when considering fluorosis of any level (detected under highly controlled, clinical conditions; 90 studies, 180,530 participants). Over 97% of the studies were at high risk of bias and there was substantial between-study variation.

AUTHORS' CONCLUSIONS

There is very little contemporary evidence, meeting the review's inclusion criteria, that has evaluated the effectiveness of water fluoridation for the prevention of caries.The available data come predominantly from studies conducted prior to 1975, and indicate that water fluoridation is effective at reducing caries levels in both deciduous and permanent dentition in children. Our confidence in the size of the effect estimates is limited by the observational nature of the study designs, the high risk of bias within the studies and, importantly, the applicability of the evidence to current lifestyles. The decision to implement a water fluoridation programme relies upon an understanding of the population's oral health behaviour (e.g. use of fluoride toothpaste), the availability and uptake of other caries prevention strategies, their diet and consumption of tap water and the movement/migration of the population. There is insufficient evidence to determine whether water fluoridation results in a change in disparities in caries levels across SES. We did not identify any evidence, meeting the review's inclusion criteria, to determine the effectiveness of water fluoridation for preventing caries in adults.There is insufficient information to determine the effect on caries levels of stopping water fluoridation programmes.There is a significant association between dental fluorosis (of aesthetic concern or all levels of dental fluorosis) and fluoride level. The evidence is limited due to high risk of bias within the studies and substantial between-study variation.