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.

Multivariable Projections of Caries-Free Prevalence and the Associated Factors from 2019 to 2030 among Schoolchildren Aged 6, 12 and 16-Year-Old in Malaysia

This study identified caries-free associated factors and conducted multivariable projections of the caries-free prevalence until 2030 among six-, 12-, and 16-year-old schoolchildren in Malaysia. It was a secondary data analysis of caries-free prevalence and potential associated factors obtained from the Health Information Management System (HIMS), Department of Statistics Malaysia (DOSM), and Food Balance Sheets (FBS). Multiple linear regression and regression with ARMA errors were employed to determine the associated factors and predict the caries-free prevalence from 2019 or 2020 until 2030 for the six-, 12-, and 16-year-old groups, respectively. Gross Domestic Product (GDP) and household income, sugar consumption, and water fluoridation were significantly associated with caries-free status, with the most impactful in all age groups being water fluoridation. With the projected values of the associated factors, the caries-free prevalence in schoolchildren of all age groups in Malaysia is predicted to increase in the next decade. Similar to the past decade, the prevalence trend will remain the highest among the 12-year-olds and the lowest among six-year-olds. Caries-free prevalence was predicted to increase by 9.10%, 15.52%, and 15.10% in the six-, 12-, and 16-year-old groups, respectively. The prevalence multiplied the highest at four times greater than in the past ten years among 16-year-olds, compared with less than 2% in the six- and 12-year-old groups. In conclusion, by factoring in economic factors, sugar consumption, water fluoridation, and age groups, the caries-free prevalence of schoolchildren in Malaysia is projected to increase at different rates in the next decade until 2030. Thus, strategic oral health plans to recognise effective promotion programmes and strengthen others for each age group are crucial.

A Global Perspective of Racial-Ethnic Inequities in Dental Caries: Protocol of Systematic Review

Though current evidence suggests that racial-ethnic inequities in dental caries persist over time and across space, their magnitude is currently unknown from a global perspective. This systematic review aims to quantify the magnitude of racial/ethnic inequities in dental caries and to deconstruct the different taxonomies/concepts/methods used for racial/ethnic categorization across different populations/nations. This review has been registered in PROSPERO; CRD42021282771. An electronic search of all relevant databases will be conducted until December 2021 for both published and unpublished literature. Studies will be eligible if they include data on the prevalence or severity of dental caries assessed by the decayed, missing, filled teeth index (DMFT), according to indicators of race-ethnicity. A narrative synthesis of included studies and a random-effects meta-analysis will be conducted. Forest plots will be constructed to assess the difference in effect size for the occurrence of dental caries. Study quality will be determined via the Newcastle-Ottawa Scale and the GRADE approach will be used for assessing the quality of evidence. This systematic review will enhance knowledge of the magnitude of racial/ethnic inequities in dental caries globally by providing important benchmark data on which to base interventions to mitigate the problem and to visualize the effects of racism on oral health.

Impact of water fluoridation on dental caries decline across racial and income subgroups of Brazilian adolescents

OBJECTIVES

The aim of this study was to assess the impact of community water fluoridation (CWF) on differences in dental caries decline across racial and socioeconomic subgroups of Brazilian adolescents.

METHODS

Two nationwide Brazilian population-based oral health surveys were used (Brazilian Oral Health Survey 2003 and 2010). In total, 7,198 adolescents from 15 years to 19 years old living in 50 cities investigated in both surveys were included. The mean numbers of untreated decayed teeth (DT) according to racial (Whites vs. Browns/Blacks) and socioeconomic subgroups (at or above the minimum wage per capita vs. under) were analysed. Difference-in-differences negative binomial regressions were adjusted by schooling, age, and sex. Decayed, missing, and filled teeth and DT prevalence, calculated as a categorical variable, were used in sensitivity analyses.

RESULTS

The adjusted difference of reduction in DT was similar across socioeconomic subgroups (β=-0.05; 95% confidence interval [CI], -0.45 to 0.35) and favoured, but not to a significant degree, Whites (β=-0.34; 95% CI, -0.74 to 0.04) compared to Brown/Blacks in fluoridated areas. In non-fluoridated areas, significant differences were observed in the mean number of DT, favouring the higher socioeconomic subgroup (β=-0.26; 95% CI, -0.53 to -0.01) and Whites (β=-0.40; 95% CI, -0.69 to -0.11) in relation to their counterparts. The sensitivity analyses confirmed the findings.

CONCLUSIONS

The similar reduction in DT across income subgroups suggests that CWF has had a beneficial effect on tackling income inequalities in dental caries within a 7-year timeframe.

Community water fluoridation and the integrity of equitable public health infrastructure

Community water fluoridation is a population health program that is in a unique position to equitably prevent dental caries across all socioeconomic groups. A review of the 76‐year long history of community water fluoridation shows that the challenges to expanding this program persist despite continued evidence of its efficacy. We offer dental health practitioners an opportunity to share the evidence of this oral disease prevention program with the communities they serve. While dental caries is still the most prevalent chronic disease that disproportionately effects lower socioeconomic status communities, community water fluoridation continues to decrease cavities by 25% at the population level. COVID‐19 has reaffirmed the importance of disease prevention and valuing public health infrastructure. There is a continued need for community water fluoridation to offer equitable access to oral disease prevention interventions.

Do network centrality measures predict dental outcomes of Indigenous children over time?

BACKGROUND

Centrality measures identify items that are central to a network, which may inform potential targets for oral interventions.

AIM

We tested whether centrality measures in a cross-sectional network of mothers' baseline factors are able to predict the association with children's dental outcomes at age 5 years.

DESIGN

A network approach was applied to longitudinal data from a randomised controlled trial of dental caries prevention delivered to 448 women pregnant with an Indigenous child in South Australia. Central items were identified at baseline using three centrality measures (strength, betweenness, and closeness). Centrality values of mothers' outcomes were regressed with their predictive values to dental caries experience and dental service utilisation at child age 5 years.

RESULTS

Items of oral health self-efficacy and oral health literacy were central to mothers' baseline network. Strength at baseline explained 51% and 45% of items' predictive values to dental caries experience and dental service utilisation at child age 5 years, respectively. Adjusted and unadjusted values of node strength for the children's oral health network were highly correlated.

CONCLUSION

Strength at baseline successfully identified mothers' items with greater importance to dental caries experience and dental service utilisation at child age 5 years.

Dynamics in oral health-related factors of Indigenous Australian children: A network analysis of a randomized controlled trial

OBJECTIVES

Network analysis is an innovative, analytic approach that enables visual representation of variables as nodes and their corresponding statistical associations as edges. It also provides a new way of framing oral health-related questions as complex systems of variables. We aimed to generate networks of oral health variables using epidemiological data of Indigenous children, and to compare network structures of oral health variables among participants who received immediate or delayed delivery of an oral health intervention.

METHODS

Epidemiological data from 448 mother-child dyads enrolled in a randomized controlled trial of dental caries prevention in South Australia, Australia, were obtained. Networks were estimated with nodes representing study variables and edges representing partial correlation coefficients between variables. Data included dental caries, impact on quality of life, self-rated general health, self-rated oral health, dental service utilization, knowledge of oral health, fatalism and self-efficacy in three time points. Communities of nodes, centrality, clustering coefficient and network stability were estimated.

RESULTS

The oral health intervention interacted with the network through self-rated general health and knowledge of oral health. Networks depicting groups shortly after receiving the intervention presented higher clustering coefficients and a similar arrangement of nodes. Networks tended to return to a preintervention state.

CONCLUSION

The intervention resulted in increased connectivity and changes in the structure of communities of variables in both intervention groups. Our findings contribute to elucidating dynamics between variables depicting oral health networks over time.

The impact of different determinants on the dental caries experience of children living in Australia rural and urban areas

AIMS

Evidence suggests there are geographical variations in child oral health and this has prompted research into determinants of that variation. This study aimed to investigate factors attributable to the difference in child oral health between urban and rural areas in Australia.

METHOD

Data were from the National Child Oral Health Study 2012-14, a population-based study of 5- to 14-year-old children, who underwent oral epidemiological examinations by trained examiners. Caries prevalence (dmfs/DMFS > 0) and experience (dmfs/DMFS count) in the primary dentition (5- to 8-year-old) and permanent dentition (9- to 14-year-old) were calculated. Children were grouped by residential location (urban or rural areas). A parental questionnaire collected information on family socio-economic factors, and individual health behaviours (dental access, sugar consumption and toothbrushing). Residential history was used to calculate lifetime exposure to water fluoridation (WF). Analyses were weighted to produce population-representative estimates. The primary outcomes were assessed separately for the two groups in regression models with robust standard error estimation to estimate prevalence ratios and mean ratios and their 95% confidence intervals. Population Attributable Fractions were calculated using the population distribution of the exposures and their adjusted estimates.

RESULTS

10 581 5- to 8-year-old and 14 041 9- to 14-year-old children were included. Caries prevalence was higher in rural than in urban areas. In multivariable models, exposure to fluoridation, reason for dental visit and consumption of sugary beverages were consistently associated with caries prevalence and experience. WF coverage attributed to differences in caries prevalence (10% vs 21%) and experience (14% vs 35%) in the permanent dentition. High consumption of sugary beverages attributed to a higher primary and permanent dental caries experience in rural than in urban areas. Dental access was also attributed to the differences between the two areas.

CONCLUSION

Factors at both community and individual levels attributed to the observed differences in child caries prevalence and experience between urban and rural areas.

Effects of Community Water Fluoridation on Dental Caries Disparities in Adolescents

Despite improvements in the prevalence of dental caries, disparities are still observed globally and in the U.S. This study examined whether community water fluoridation (CWF) reduced dental caries disparities in permanent teeth of 10- to 19-year-old schoolchildren in North Carolina. We used cross-sectional data representing K-12 schoolchildren in North Carolina (NC) public schools. A poisson regression model was used to determine whether the association between children’s parental educational attainment and the prevalence of dental caries of children differed by children’s lifetime CWF exposure. We analyzed data on 2075 students. Among the children without any CWF exposure in their life, statistically significant caries disparities by parental educational attainment were observed. Compared to the children of parents with more than high school education, the relative risk for those with a parent with a high school education was 1.16 (95% CI = 1.01, 1.33) and those with less than a high school education was 1.27 (95% CI = 1.02, 1.60). In contrast, these disparities were not observed among children exposed to CWF throughout their lives. Socioeconomic disparities in dental caries were not observed among 10–19-year-old schoolchildren with lifetime CWF exposure. CWF seemed to reduce dental caries disparities.

Teeth: Small but Mighty and Mighty Important. A Comprehensive Review of Children's Dental Health for Primary Care Clinicians

Healthy teeth allow us to eat and stay well-nourished. Although primary care clinicians receive limited training about teeth, given the common nature of dental problems, it is important that they understand and recognize normal and abnormal dental conditions and can implement primary and secondary prevention of dental conditions in their practice. PubMed has been used to search the scientific literature for evidence on the following topics: normal dental development, dental abnormalities, malocclusion, teething, dental caries and related epidemiology and prevention, fluoride, dental injury and its management and prevention; and identification, prevention and treatment of gingivitis and periodontal disease. Literature review relied on randomized controlled trials, meta-analyses, systematic reviews, and Cochrane reviews when relevant and available. Other sources of evidence included cohort and case-control studies. Consensus statements and expert opinion were used when there was a paucity of high-quality research studies. The literature has been synthesized on these topics to make them relevant to pediatric primary care clinicians, and as available, the strength of evidence has been characterized when making clinical recommendations.

Is There an Association between Breastfeeding and Dental Caries among Three-Year-Old Australian Aboriginal Children?

An unresolved question about breastfeeding is its effect on caries, in particular, early childhood caries (ECC). In secondary analyses of data from an ECC intervention, we describe breastfeeding among Aboriginal children and associations between breastfeeding and ECC. Breastfeeding (duration and exclusivity to six months) was grouped into mutually exclusive categories. ECC was observed by a calibrated dental professional. Outcomes were prevalence of ECC (% decayed, missing, and filled teeth in the primary dentition (% dmft>0)) and caries severity (mean number of decayed, missing, and filled surfaces (mean dmfs)) in children aged three years. Analyses were adjusted for confounding. Multiple imputation was undertaken for missing information. Of 307 participants, 29.3% were never breastfed, 17.9% exclusively breastfed to six months, and 9.3% breastfed >24 months. Breastfeeding >24 months was associated with higher caries prevalence (adjusted prevalence ratio (PRa) 2.06 (95%CI 1.35, 3.13, p-value = 0.001) and mean dmfs (5.22 (95% CI 2.06, 8.38, p-value = 0.001), compared with children never breastfed. Exclusive breastfeeding to six months with breastfeeding <24 months was associated with 1.45 higher caries prevalence (95% CI -0.92, 2.30, p-value = 0.114) and mean dmfs 2.04 (-0.62, 4.71, p-value = 0.132), compared with never breastfeeding. The findings are similar to observational studies on breastfeeding and caries but not with randomized controlled trials of breastfeeding interventions. Despite attending to potential biases, inconsistencies with trial evidence raises concerns about the ability to identify causal effects of breastfeeding in observational research.

The Impact of Policy Modifiable Factors on Inequalities in Rates of Child Dental Caries in Australia

Background: Poor oral health in childhood can lead to adverse impacts later in life. We aimed to estimate the prevalence and population distribution of childhood dental caries in Australia and investigate factors that might ameliorate inequalities. Methods: Data from the nationally representative birth cohort Longitudinal Study of Australian Children (N = 5107), using questions assessing: The experience of dental caries during each biennial follow-up period (2–3 years to 10–11 years), socioeconomic position (SEP), and policy modifiable oral health factors. Results: The odds of dental caries were higher for children with lowest vs. highest SEP (adjusted OR (adjOR) 1.92, 95% CI 1.49–2.46), and lower where water was fluoridated to recommended levels (adjOR 0.53, 95% CI 0.43–0.64). There was no evidence of an association between caries experience and either reported sugary diet or tooth brushing. When SEP and fluoridation were considered in conjunction, compared to the highest SEP group with water fluoridation children in the lowest SEP with fluoridation had adjOR 1.54 for caries, (95% CI 1.14–2.07), and children in the lowest SEP without fluoridation had adjOR 4.06 (95% CI 2.88–5.42). For patterns of service use: The highest SEP group reported a greater percentage of service use in the absence of caries. Conclusions: Dental caries appears prevalent and is socially distributed in Australia. Policy efforts should consider how to ensure that children with dental caries receive adequate prevention and early care with equitable uptake.

Risk indicators for untreated dental decay among Indigenous Australian children

OBJECTIVE

To investigate risk indicators for untreated dental decay among Indigenous Australian children using a national representative sample.

METHODS

Data were from the National Child Oral Health Study 2012-2014, which included a nationally representative sample of Indigenous Australian children aged 5-14 years. Outcomes were the prevalence (% ds/DS >0) and severity (mean ds/DS) of untreated dental decay at the tooth surface level. Caries of the primary dentition was estimated among 5- to 10-year-olds, while that of the permanent dentition was among 8- to 14-year-olds. Independent variables included residential location, household income, frequency and age commencement of toothbrushing, sugar-sweetened beverages (SSB) consumption, dental visiting and residential fluoridation status. Multivariable log-Poisson regression models with robust standard error estimation were used to identify risk indicators for untreated decay. The complex sampling design was taken into account in all analyses.

RESULTS

There were 720 5- to 10-year-old and 736 8- to 14-year-old Indigenous children. Indigenous children experienced significant amount of untreated dental caries. Among 5- to 10-year-olds, % ds >0 was 43.1 (95% CI: 36.8-49.6) and mean ds was 3.4 (95% CI: 2.4-4.4). Among 8- to 14-year-olds, % DS >0 was 27.3 (22.3-32.9), while mean DS was 0.8 (0.6-1.0). In multivariable modelling, risk indicators for % ds >0 among 5- to 10-year-olds were low household income, commencing toothbrushing after 30 months of age, consuming 2+ cups of SSB per day and not residing in fluoridated areas. Risk indicators for mean ds among 5- to 10-year-olds included infrequent toothbrushing and consuming 2+ cups of SSB per day. Risk indicators for % DS >0 among 8- to 14-year-olds were low household income, while risk indicators for mean DS among 8- to 14-year-olds were residing in non-capital city, low household income, consuming 2+ cups of SSB per day and not residing in fluoridated areas.

CONCLUSION

Indigenous Australian children experienced significant amount of untreated dental caries. Risk indicators for untreated decay included demographic factors, socioeconomic factors, oral hygiene behaviours, dietary behaviours and environmental factors.

Fluoridated Water Modifies the Effect of Breastfeeding on Dental Caries

Breastfeeding is important for health and development. Yet, the interaction between breastfeeding duration and usage of fluoridated water on caries experience has not been investigated. This study examined exposure to fluoridation as an effect modifier of the association between breastfeeding duration and caries. The 2012 to 2014 national population-based study of Australian children involved parental questionnaires and oral epidemiological assessment. Children were grouped by parent-reported breastfeeding duration into minimal (none or <1 mo), breastfed for 1 to <6 mo, breastfed for 6 to 24 mo, and sustained (>24 mo). Residential history and main water source used for the first 2 y of life were collected to group children into exposed (WF) and nonexposed (NF) to fluoridation. Socioeconomic status, infant formula feeding, and sugar-sweetened beverage (SSB) consumption data were collected. The prevalence and severity of caries in children aged 5 to 6 y were primary outcomes. Multivariable regression models with robust error estimation were generated to compute prevalence ratios (PRs) and mean ratios (MRs) for 3 breastfeeding groups against the reference (breastfed for 6-24 mo). Of the 5- to 6-y-old children, 2,721 were in the WF and 1,737 were in the NF groups. The groups had comparable distributions of socioeconomic factors, infant formula feeding, and SSB consumption. There were U-shape distributions of caries experience among breastfeeding groups, being more pronounced among NF children. Among NF children, the minimal and sustained breastfeeding groups had significantly higher PR (1.4 [1.1-1.9] and 1.8 [1.4-2.4]) and MR (2.1 [1.4-3.3] and 2.4 [1.4-4.1]) than the reference group. However, among the WF children, this association between breastfeeding duration and caries attenuated after adjustment for other factors. The study contributes evidence of a nonlinear (U-shape) association between breastfeeding duration and dental caries. Early life exposure to fluoridated drinking water attenuated the potential cariogenic effect of both lack of and sustained breastfeeding.

Racial Inequalities in Oral Health

Together with other social categories, race has been at the core of much scholarly work in the area of humanities and social sciences, as well as a host of applied disciplines. In dentistry, debates have ranged from the use of race as a criterion for the recommendation of specific dental procedures to a means of assessing inequalities in a variety of outcomes. What is missing in these previous discussions, though, is a broader understanding of race that transcends relations with genetic makeup and other individual-level characteristics. In this review, we provide readers with a critique of the existing knowledge on race and oral health by answering the following 3 guiding questions: (1) What concepts and ideas are connected with race in the field of dentistry? (2) What can be learned and what is absent from the existing literature on the topic? (3) How can we enhance research and policy on racial inequalities in oral health? Taken together, the reviewed studies rely either on biological distinctions between racial categories or on other individual characteristics that may underlie racial disparities in oral health. Amidst a range of individual-level factors, racial inequalities have often been attributed to lower socioeconomic status and “health-damaging” cultural traits, for instance, patterns of and reasons for dental visits, dietary habits, and oral hygiene behaviors. While this literature has been useful in documenting large and persistent racial gaps in oral health, wider sociohistorical processes, such as systemic racism, as well as their relationships with economic exploitation, social stigmatization, and political marginalization, have yet to be operationalized among studies on the topic. A nascent body of research has recently begun to address some of these factors, but limited attention to structural theories of racism means that many more studies are needed to effectively mitigate racial health differentials.