Effect of Fluoride Concentration in Drinking Water on Dental Fluorosis in Southwest Saudi Arabia

Web of Science-Based Scientometric Assessment of the Importance of Filtered Water in Dentistry: Spatiotemporal Dynamics, Emerging Patterns, and Collaboration

Objective

The aim of this study was to examine the characteristics of scientific production related to the use of filtered water in the field of dentistry. Material and Methods. A quantitative and descriptive observational study was carried out with a scientometric approach. Data were collected from the Web of Science (WOS) database during the period January 1991 to December 2023. A search strategy incorporating a combination of MeSH terms, including terms and thesauri related to "filtered water" and "dentistry", was used. R Studio version 4.3.2 and CiteSpace 6.2.R7 were used for data analysis.

Results

Over the 32-year study period, 227 scholarly papers from 134 different sources were reviewed. The literature in this field has shown an annual growth rate of 10.44%. During the year 2010, a steady movement in the number of publications and authors was observed, with considerable collaborative interaction. In the year 2020, a large interaction between publications and their citations was found. The "Citation Burst" graph identified three references that have experienced the largest "burst" of citations in an evaluated period. Lotka's law described the productivity of authors, finding that most authors have published only one paper, while a smaller number of authors have published two papers. Most authors contributed a small number of articles, while a few authors contributed a large amount of the existing literature.

Conclusion

A comprehensive overview of the scientific production related to the use of filtered water in dentistry over a span of 32 years is provided. The results highlight the growing interdisciplinarity and international collaboration in this field. Finally, the importance of filtered water in dentistry and its growing relevance in the scientific literature are emphasized.

Systematic review of epidemiological and toxicological evidence on health effects of fluoride in drinking water

INTRODUCTION

Fluoride is a naturally occurring substance that is also added to drinking water, dental hygiene products, and food supplements for preventing dental caries. Concerns have been raised about several other potential health risks of fluoride.

OBJECTIVE

To conduct a robust synthesis of evidence regarding human health risks due to exposure to fluoride in drinking water, and to develop a point of departure (POD) for setting a health-based value (HBV) for fluoride in drinking water.

METHODS

A systematic review of evidence published since recent reviews of human, animal, and in vitro data was carried out. Bradford Hill considerations were used to weigh the evidence for causality. Several key studies were considered for deriving PODs.

RESULTS

The current review identified 89 human studies, 199 animal studies, and 10 major in vitro reviews. The weight of evidence on 39 health endpoints was presented. In addition to dental fluorosis, evidence was considered strong for reduction in IQ scores in children, moderate for thyroid dysfunction, weak for kidney dysfunction, and limited for sex hormone disruptions.

CONCLUSION

The current review identified moderate dental fluorosis and reduction in IQ scores in children as the most relevant endpoints for establishing an HBV for fluoride in drinking water. PODs were derived for these two endpoints, although there is still some uncertainty in the causal weight of evidence for causality for reducing IQ scores in children and considerable uncertainty in the derivation of its POD. Given our evaluation of the overall weight of evidence, moderate dental fluorosis is suggested as the key endpoint until more evidence is accumulated on possible reduction of IQ scores effects. A POD of 1.56 mg fluoride/L for moderate dental fluorosis may be preferred as a starting point for setting an HBV for fluoride in drinking water to protect against moderate and severe dental fluorosis. Although outside the scope of the current review, precautionary concerns for potential neurodevelopmental cognitive effects may warrant special consideration in the derivation of the HBV for fluoride in drinking water.

Effect of Drinking Water Fluoride on Gingivitis and Caries: A Study in Peat and Non-Peat Land: A Comparative Cross-Sectional Study

Aim

Humans get fluoride from food and water available in their environment. The source of clean water in peatlands comes from rainwater with a low mineral content, especially fluoride. The objective of this study was to investigate the correlation between the fluoride level in drinking water and salivary fluoride levels, as well as their potential impact on dental and oral health conditions.

Materials and Methods

It is a causal-comparative study with a cross-sectional approach at the Health Polytechnics of Pontianak and Yogyakarta. The population were indigenous people in peat land (Pontianak) and non-peat land (Yogyakarta). The data were pH and mineral content in drinking water, saliva, the number of Streptococcus mutans colonies, dental caries rates, and gingivitis.

Results

Drinking water fluoride is only significantly correlated with salivary fluoride on non-peat land. If these data are combined, it can be seen that drinking water fluoride is positively correlated (P < 0.05; CI 95%) with pH water, fluoride water, and pH saliva. Increased levels of fluoride in drinking water were negatively correlated with gingivitis, dental caries, and S. mutans.

Conclusion

Drinking water fluoride is negatively correlated with dental caries and gingivitis in peatland and non-peatland communities, but would be significantly associated with dental caries and gingivitis if both peatland and non-peatland data were analyzed together. This is due to the low content of fluoride in the drinking water of peatland. Therefore, it is necessary to add fluoride gel to the teeth to prevent the development of dental caries.

Investigation on Applying Biodegradable Material for Removal of Various Substances (Fluorides, Nitrates and Lead) from Water

Sapropel was used as a biodegradable material for water treatment. Sapropel is a sedimentary layer of a mix of organic and inorganic substances accumulated in the bottoms of lakes for thousands of years. It is a jelly-like homogeneous mass and has properties of sorption. Sapropel is used as a biosorbent and an environment-friendly fertiliser, and it is used in building materials and in the beauty industry as well. In water, there are abundant various solutes that may cause a risk to human health. Such substances include fluorides, nitrates and lead in different sources of water. The goal of this investigation is to explore and compare the efficiencies of removal of different pollutants (fluorides, nitrates and lead) from aqueous solutions upon using sapropel as a sorbent. In this research, various doses of sapropel (0.1, 0.5, 1, 5, 10, 20, 50, 100 and 200 g/L) and various mixing times (15, 30, 60, 90 and 120 min) were used for removal of fluorides, nitrates and lead from aqueous solutions. It was found that the maximum efficiency (up to 98.57%) of lead removal from aqueous solutions by sapropel was achieved when the minimum doses of it (0.1 and 0.5 g/L) were used. The most efficient removal of fluorides (64.67%) was achieved by using 200 g/L of sapropel and mixing for 120 min. However, sapropel does not adsorb nitrates from aqueous solutions.

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.

Mean Fluoride Concentration in Drinking Water Sources of a Municipality: A Descriptive Cross-sectional Study

Introduction

Fluoride is essential for the growth and development of teeth and bone. Excess or less fluoride consumption can have harmful effects on our bodies. Fluoride level of 0.5-1.5 mg/l is said to be optimized according to the World Health Organization. The level of fluoride varies among the different geographical regions and water sources. It is essential to find out the fluoride content of various water sources used for drinking purposes. The aim of this study was to find the mean concentration of fluoride in drinking water sources of a municipality.

Methods

A descriptive cross-sectional study was conducted in a Municipality. The study was conducted from 1 December 2021 to 30 December 2021 after receiving ethical approval from the Ethical Review Board (Reference number: 1134). Water samples were collected and the fluoride content was estimated using 2-parasulfophenylazo-1,8-dihydroxy-3,6-napthalene-disulfonate colorimetric method. The data collected from the laboratory were calculated and presented in the form of a table. Point estimate and 95% Confidence Interval were calculated.

Results

The mean value of fluoride content in 160 collected water samples was 0.369±0.275 mg/l (0.33-0.41, 95% Confidence Interval). Among the different wards, the fluoride content was 0.708±0.27 mg/l in ward number 12 followed by a fluoride content of 0.57±0.19 mg/l in ward number 5.

Conclusions

In this study, the mean fluoride levels were lower when compared with similar studies conducted in similar settings. The levels were lower than that recommended by the World Health Organization. The various controlled methods of fluoridation have to be quickly initiated. Other means of fluoride consumption, like the use of fluoridated toothpaste, has to be recommended.

Keywords

dental caries; drinking water; fluoride.

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.