A 4-year assessment of a new water-fluoridation scheme in New South Wales, Australia

The CATFISH study: An evaluation of a water fluoridation program in Cumbria, UK

OBJECTIVES

The objective was to assess the effectiveness of a Water Fluoridation program on a contemporary population of children.

METHODS

The study used a longitudinal prospective cohort design. In Cumbria, England, two groups of children were recruited and observed over a period of 5-6 years. The Birth Cohort consisted of families recruited from two hospitals in Cumbria where children were conceived after water fluoridation was reintroduced. The systemic and topical effects of community water fluoridation were evaluated in the Birth Cohort. The Older Cohort were approximately 5 years old and recruited from primary schools in Cumbria, shortly after water fluoridation was reintroduced. The predominantly topical effects of fluoridated water were evaluated in the Older Cohort. The primary outcome was the proportion of children with clinical evidence of caries experience in their primary (Birth Cohort) or permanent teeth (Older Cohort). Unadjusted and adjusted regression models were used for analysis.

RESULTS

The final clinical examinations for the Birth Cohort involved 1444 participants (mean age 4.8 years), where 17.4% of children in the intervention group were found to have caries experience, compared to 21.4% in the control group. A beneficial effect of water fluoridation was observed adjusting for deprivation (a socioeconomic measure), sex, and age, (adjusted odds ratio 0.74 95% CI 0.55 to 0.98). The final Older Cohort clinical examinations involved 1192 participants (mean age 10.8 years) where 19.1% of children in the intervention group were found to have caries experience compared to 21.9% in the control group (adjusted odds ratio 0.80, 95% CI 0.58 to 1.09). For both the Birth Cohort and Older Cohort there was evidence of a beneficial effect on dmft/DMFT count (IRR 0.61, 95% CI 0.44, 0.86) and (IRR 0.69, 95% CI 0.52, 0.93) respectively. No conclusive proof was found to indicate that the effectiveness of water fluoridation differed across area deprivation quintiles.

CONCLUSIONS

In the contemporary context of lower caries levels and widespread use of fluoride toothpaste, the impact of water fluoridation on the prevalence of caries was smaller than previous studies have reported. It is important to consider the clinical importance of the absolute reduction in caries prevalence against the use of other dental caries preventive measures.

Water fluoridation in Australia: A systematic review

Water fluoridation is considered a safe and effective public health strategy to improve oral health. This review aimed to systematically summarize the available evidence of water fluoridation in Australia, focusing on the history, health impacts, cost effectiveness, challenges, and limitations. A systematic search was conducted on the Ovid Medline, Web of Science, Scopus, ProQuest Central, Cinahl, and Informit databases to identify literature on water fluoridation in Australia. A grey literature search and backward snowballing were used to capture additional literature. Primary studies, reviews, letters, and opinion papers were included in the quantitative analysis and summarized based on the year of publication and geographical location. The data were extracted from primary studies and summarized under three subheadings: history, community health impacts and the limitations and challenges. Water fluoridation in Australia was first implemented in 1953 in Tasmania. Most states and territories in Australia embraced water fluoridation by 1977 and currently, 89% of the Australian population has access to fluoridated drinking water. Studies report that water fluoridation has reduced dental caries by 26-44% in children, teenagers, and adults, benefiting everyone regardless of age, income, or access to dental care. It has been recognized as a cost-effective intervention to prevent dental caries, especially in rural and low-income areas. Water fluoridation as a public health measure has faced challenges, including political and public opposition, implementation and maintenance costs, access and equity, communication and education, and ethical concerns. Variations in research activities on water fluoridation across Australian states and territories over the last seven decades can be due to several factors, including the time of implementation, funding, and support. Ongoing monitoring and research to review and update optimal fluoride levels in drinking water in Australia is warranted to ensure sustainable benefits on oral health while preventing any adverse impacts.

Effect of fluoridated water on dental caries and fluorosis in schoolchildren who use fluoridated dentifrice

This cross-sectional study evaluated the prevalence and severity of dental caries and fluorosis in children and adolescents using fluoridated toothpaste, from areas with and without fluoridated water. Parents of 5-year-old children and 12-year-old adolescents from neighbourhoods that are supplied with and without fluoridated water answered questionnaires for determining socio-economic and demographic characteristics and habits related to oral health. The individuals were examined, and dental caries and fluorosis were measured by dmft/DMFT and TF indexes, respectively. Descriptive, bivariate and logistic regression analyses were performed (p < 0.05). Of 692 participants, 47.7% were 5-year-olds and 52.3% were 12-year-olds. The mean dmft/DMFT in the 5-year-olds/ 12-year-olds from Exposed and Not Exposed fluoridated water groups was 1.53 (± 2.47) and 3.54 (± 4.10) / 1.53 (± 1.81) and 3.54 (± 3.82), respectively. Children (OR = 2.86, 95% CI = 1.71-4.75) and adolescents (OR = 1.95, 95% CI = 1.24-3.05), who did not consume fluoridated water, had greater caries experience. Among adolescents, there was an association between fluoridated water and the prevalence of very mild/mild fluorosis (OR = 5.45, 95% CI: 3.23-9.19) and moderate fluorosis (OR = 11.11, 95% CI = 4.43-27.87). Children and adolescents, who consumed fluoridated water, presented lower prevalence and severity of dental caries compared to those who used only fluoridated toothpaste as the source of fluoride. There is an association between water fluoridation and very mild/mild and moderate fluorosis in adolescents.

The Prevalence of Dental Caries in Primary Dentition in 3- to 5-Year-Old Preschool Children in Northern China

Objectives

To investigate the prevalence and factors promoting caries in primary dentition of 3-5-year-old children in Northeast China.

Materials and Methods

Data of 1,229 children aged 3 to 5 years were randomly selected. The caries prevalence and other indicators were assessed, and the results analyzed by SPSS. A questionnaire was also given to the children's guardians to ascertain the potential risk factors associated with caries.

Results

The decayed, missing, and filled teeth (dmft) index in children aged 3, 4, and 5 years old was 3.17, 5.13, and 6.07, respectively, while the caries prevalence rate was 62.16%, 75.89%, and 87.28% accordingly. The incidence of caries among rural children was higher than that in urban areas. Regarding oral health awareness, it was found that parents in urban areas had more accurate perceptions of oral health problems. It was also noted that the children's brushing habits were worrying. Family economic and medical resources are not the main causes of serious dental caries in rural areas.

Conclusions

The oral health status of children aged 3-5 years is not optimistic. Many parents have a low awareness of oral health. Strengthening the promotion of oral health knowledge is an effective way to change the situation.

Calcium Intake and Health

There are striking inequities in calcium intake between rich and poor populations. Appropriate calcium intake has shown many health benefits, such as reduction of hypertensive disorders of pregnancy, lower blood pressure particularly among young people, prevention of osteoporosis and colorectal adenomas, lower cholesterol values, and lower blood pressure in the progeny of mothers taking sufficient calcium during pregnancy. Studies have refuted some calcium supplementation side effects like damage to the iron status, formation of renal stones and myocardial infarction in older people. Attention should be given to bone resorption in post-partum women after calcium supplementation withdrawal. Mechanisms linking low calcium intake and blood pressure are mediated by parathyroid hormone raise that increases intracellular calcium in vascular smooth muscle cells leading to vasoconstriction. At the population level, an increase of around 400–500 mg/day could reduce the differences in calcium intake between high- and middle-low-income countries. The fortification of food and water seems a possible strategy to reach this goal.

Age-sex specific and sequela-specific disability-adjusted life years (DALYs) due to dental caries preventable through water fluoridation: An assessment at the national and subnational levels in Iran, 2016

We assessed disability-adjusted life years (DALYs) due to dental caries preventable through water fluoridation apportioned by sex, age group, sequela, province, and community type in Iran, 2016. The burden of disease due to dental caries was extracted from the Global Burden of Disease Study 2016 (GBD 2016) and the caries preventive effect of water fluoridation was calculated using a database of fluoride levels in drinking water. All the preventable DALYs were caused by years lived with disability (YLDs) because of the non-fatal character of dental caries. DALYs and DALY rate (per 100,000 people) preventable through water fluoridation at the national level in 2016 were 14,971 (95% uncertainty interval 7348- 24,725) and 18.73 (9.19-30.93), respectively. The national population preventable fraction (PPF) of dental caries by water fluoridation was determined to be as high as 0.176 (0.141-0.189). The share of sequelae in the preventable DALYs at the national level were estimated to be 76.8% for edentulism and severe tooth loss, 21.4% for caries of permanent teeth, and 1.8% for caries of deciduous teeth. The national DALYs and DALY rate preventable through water fluoridation exhibited no difference by sex, but considerably increased by age from 110 (37-223) and 1.5 (0.5-3.1) for the age group 0-4 y to 4331 (2334-6579) and 88.9 (47.9-135.1) for the age group 65 y and older, respectively. Over 80% of the national preventable DALYs occurred in urban areas due to higher population and lower coverage of fluoridated drinking water. The highest provincial DALYs and DALY rate preventable by water fluoridation were observed in Tehran and Gilan to be 3776 (1866-6206) and 37.2 (18.6-60.8), respectively. The results indicated that water fluoridation can play a profound role in the promotion of dental public health and compensate the spatial inequality and increasing temporal trend of health losses from dental caries at the national level.

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.