The effect of lifetime fluoridation exposure on dental caries experience of younger rural adults

Effect of fluoridated water on invasive NHS dental treatments for adults: the LOTUS retrospective cohort study and economic evaluation

Background

Most water fluoridation studies were conducted on children before the widespread introduction of fluoride toothpastes. There is a lack of evidence that can be applied to contemporary populations, particularly adolescents and adults.

Objective

To pragmatically assess the clinical and cost effectiveness of water fluoridation for preventing dental treatment and improving oral health in a contemporary population of adults, using a natural experiment design.

Design

Retrospective cohort study using routinely collected National Health Service dental claims (FP17) data.

Setting

National Health Service primary dental care: general dental practices, prisons, community dental services, domiciliary settings, urgent/out-of-hours and specialised referral-only services.

Participants

Dental patients aged 12 years and over living in England (n = 6,370,280).

Intervention and comparison

Individuals exposed to drinking water with a fluoride concentration ≥ 0.7 mg F/l between 2010 and 2020 were matched to non-exposed individuals on key characteristics using propensity scores.

Outcome measures

Primary: number of National Health Service invasive dental treatments (restorations/'fillings' and extractions) received per person between 2010 and 2020. Secondary: decayed, missing and filled teeth, missing teeth, inequalities, cost effectiveness and return on investment.

Data sources

National Health Service Business Services Authority dental claims data. Water quality monitoring data.

Primary outcome

Predicted mean number of invasive dental treatments was 3% lower in the optimally fluoridated group than in the sub/non-optimally fluoridated group (incidence rate ratio 0.969, 95% CI 0.967 to 0.971), a difference of -0.173 invasive dental treatments (95% CI -0.185 to -0.161). This magnitude of effect is smaller than what most stakeholders we engaged with (n = 50/54) considered meaningful.

Secondary outcomes

Mean decayed, missing and filled teeth were 2% lower in the optimally fluoridated group, with a difference of -0.212 decayed, missing and filled teeth (95% CI -0.229 to -0.194). There was no statistically significant difference in the mean number of missing teeth per person (0.006, 95% CI -0.008 to 0.021). There was no compelling evidence that water fluoridation reduced social inequalities in treatments received or missing teeth; however, decayed, missing and filled teeth data did not demonstrate a typical inequalities gradient. Optimal water fluoridation in England in 2010-20 was estimated to cost £10.30 per person (excluding original setup costs). Mean National Health Service treatment costs for fluoridated patients 2010-20 were 5.5% lower per person, by £22.26 (95% CI -£23.09 to -£21.43), and patients paid £7.64 less in National Health Service dental charges per person (2020 prices).

Limitations

Pragmatic, observational study with potential for non-differential errors of misclassification in fluoridation assignment and outcome measurement and residual and/or unmeasured confounding. Decayed, missing and filled teeth data have not been validated. Water fluoridation cost estimates are based on existing programmes between 2010 and 2020, and therefore do not include the potentially significant capital investment required for new programmes.

Conclusions

Receipt of optimal water fluoridation between 2010 and 2020 resulted in very small health effects, which may not be meaningful for individuals, and we could find no evidence of a reduction in social inequalities. Existing water fluoridation programmes in England produced a positive return on investment between 2010 and 2020 due to slightly lower National Health Service treatment costs. These relatively small savings should be evaluated against the projected costs and lifespan of any proposed capital investment in water fluoridation, including new programmes.

Future work

National Health Service dental data are a valuable resource for research. Further validation and measures to improve quality and completeness are warranted.

Trial registrations

This trial is registered as ISRCTN96479279, CAG: 20/CAG/0072, IRAS: 20/NE/0144.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Public Health Research programme (NIHR award ref: NIHR128533) and is published in full in Public Health Research; Vol. 12, No. 5. See the NIHR Funding and Awards website for further award information.

Determinants of oral health status: an ecological study in Iran

OBJECTIVES

The aim of this ecological study was to assess the association between behavioral, social position, circumstance factors, and caries experience in 35- to 44-year-old adults in Iran at a provincial level.

MATERIALS AND METHODS

The data from the 2011 Iranian Oral Health Survey were obtained from all 31 provinces across Iran on the population level. Oral health status was measured as the number of decayed, missing (MT), and filled (FT) teeth and the percentage of the population who were edentulous. Data were also gathered from each province on the percentage of smokers (Non-Communicable Diseases Risk Factors Surveillance Provincial Report 2009), per capita consumption of free sugars, concentration of fluoride in the drinking water (National and Sub-national Burden of Disease (NASBOD) Survey), number of dentists per 10,000 people, mean years of schooling of adults, expected years of schooling of children, life expectancy at birth and Gross National Income (Integrated Public Use Microdata Series, Global Data Lab). The data were analyzed using simple and multiple linear regression (α = 0.05).

RESULTS

Mean DMFT was positively associated with the percentage of smokers (B = 0.01 95%CI 0.01-0.14), and negatively with fluoride concentration (B =-2.6 95%CI -4.3- -0.96). The edentulousness percentage was positively associated with smoking (B = 0.2 (with 95%CI: 0.07-0.37) and negatively with mean years of education (B =-1.08 (with 95%CI: -2.04- -0.12). DT was associated with expected years of schooling (B =-0.6 (with 95%CI: -1.07- -0.17), negatively. Mt was negatively associated with life expectancy (B =-0.5 (with 95%CI: -1.1- -0.007), fluoride concentration (B =-3.4 (with 95%CI: -4.5- -1.5) and number of dentists per 10,000 people (B =-0.4 (with 95%CI: -0.8- -0.01). Mean Years of Schooling (B = 0.5 (with 95%CI: 0.2-0.8) and number of dentists per 10,000 people (B =-0.62 (with 95%CI: 0.51 - 0.48) were positively in associated with FT.

CONCLUSIONS

The present findings indicate that there were differences in the oral health measures and their social determinants among the provinces of Iran. Regarding the limitations of the study especially the limitation of the number of independent variables, it seems, this discrepancy could be better explained by social variables of the provinces such as income than by environmental factors.

Qualitative evaluation of the pre-implementation phase of a rural dental clinic co-located within a health center in the Pacific Northwest of the United States

OBJECTIVE

The development of a dental clinic within an existing Rural Health Clinic (RHC) was proposed to improve access to dental care for Medicaid enrollees in Washington. This qualitative study assessed the implementation of a co-located dental clinic in a rural community during the pre-implementation phase. Additionally, we sought to determine the needs and expectations of community members living in this rural Washington county.

METHODS

This study took place in Jefferson County, Washington, a Dental Health Professional Shortage Area. Semi-structured interviews were conducted with 42 participants, consisting of administrators (n = 9), health providers (n = 9) and community members (n = 24). Administrators and health providers were interviewed by phone. Community members were interviewed in-person at Jefferson Healthcare primary care clinics or by phone. Interview data were deductively coded, and thematic analysis with a hybrid inductive-deductive approach was used to analyse coded data.

RESULTS

Five themes were identified regarding local needs and expectations: dental care as a major need in the community, persisting barriers to dental care access, expecting more than a 'Medicaid experience', visions for a clinic that serves the community, and solutions outside the clinic to improve community oral health.

CONCLUSIONS

By improving access to dental care, a co-located dental clinic is helping to address general dental care needs in rural communities. Policy-level solutions that address housing and food insecurity, improve public transportation, and retain and expand low-income adult Medicaid dental benefits may be needed to overcome persisting barriers to oral health.

Access to dental care barriers and poor clinical oral health in Australian regional populations

BACKGROUND

This paper investigated the associations between oral health with behavioural, demographic, periodontitis risk, financial and access to dental care barriers and compared the results in three Australian regional areas.

METHODS

Data were obtained from the Australian National Study of Adult Oral Health (2017-18). Oral health status was measured using DMFT-score, and mean numbers of decayed, missing or filled teeth and periodontitis prevalence using the Center for Disease Control and Prevention (CDC) and the American Academy of Periodontology (AAP) Periodontal Classification. Analysis included these dependent variables by three regional areas, seven socio-demographic variables, two periodontal disease risk-factors, two preventive dental behaviours, two barriers to dental care and three access to dental care variables.

RESULTS

Of the 15,731 people interviewed, 5,022 were examined. There was no significant difference in periodontitis prevalence between the regions. All the socio-demographic characteristics, periodontal disease risk-factors, preventive dental behaviours were significantly associated with at least one of the dental caries indicators. In multivariable analysis, there was no significant association between regional location with any of the four clinical dental caries variables.

CONCLUSION

Poorer oral health outside major cities was associated with household income, education level, higher smoking, usual reason for and frequency of dental visiting. © 2022 Australian Dental Association.

Maintaining Good Oral Health With Fluoridated Water

Community water fluoridation (CWF) has been a public health measure against tooth decay since 1945. Strong evidence supports the use of CWF in reduction in caries risk in the pediatric population, and numerous studies also show benefit in adults. CWF remains an important contributor to oral health despite the availability and widespread use of other fluoride-containing dental products. The efficacy, safety, and optimal use of CWF will be discussed.

How effective and cost-effective is water fluoridation for adults? Protocol for a 10-year retrospective cohort study

BACKGROUND

Tooth decay can cause pain, sleepless nights and loss of productive workdays. Fluoridation of drinking water was identified in the 1940s as a cost-effective method of prevention. In the mid-1970s, fluoride toothpastes became widely available. Since then, in high-income countries the prevalence of tooth decay in children has reduced whilst natural tooth retention in older age groups has increased. Most water fluoridation research was carried out before these dramatic changes in fluoride availability and oral health. Furthermore, there is a paucity of evidence in adults. The aim of this study is to assess the clinical and cost-effectiveness of water fluoridation in preventing invasive dental treatment in adults and adolescents aged over 12.

METHODS/DESIGN

Retrospective cohort study using 10 years of routinely available dental treatment data. Individuals exposed to water fluoridation will be identified by sampled water fluoride concentration linked to place of residence. Outcomes will be based on the number of invasive dental treatments received per participant (fillings, extractions, root canal treatments). A generalised linear model with clustering by local authority area will be used for analysis. The model will include area level propensity scores and individual-level covariates. The economic evaluation will focus on (1) cost-effectiveness as assessed by the water fluoridation mean cost per invasive treatment avoided and (2) a return on investment from the public sector perspective, capturing the change in cost of dental service utilisation resulting from investment in water fluoridation.

DISCUSSIONS

There is a well-recognised need for contemporary evidence regarding the effectiveness and cost-effectiveness of water fluoridation, particularly for adults. The absence of such evidence for all age groups may lead to an underestimation of the potential benefits of a population-wide, rather than targeted, fluoride delivery programme. This study will utilise a pragmatic design to address the information needs of policy makers in a timely manner.

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.

Long-term variability in artificially and naturally fluoridated water supplies in England

OBJECTIVES

To understand the potential impact of exposure misclassification on water fluoridation studies in England, this paper aims to describe the long-term variation in water fluoride concentrations in both artificially and naturally fluoridated water supplies.

METHODS

Water fluoridation dose monitoring data were requested from all five English public water suppliers who artificially fluoridate their water, as well as from one water company that supplies naturally fluoridated water. Descriptive statistics were calculated, including annual means, standard deviations, minimum-maximum and absolute and relative frequencies.

RESULTS

Data were made available by two of the five English water companies who supply artificially fluoridated water and one water company that supplies naturally fluoridated water (40 398 individual samples). The data for fluoridated water spanned 18-35 years, whilst the data on naturally fluoridated water spanned 14 years. The artificially fluoridated samples showed wide variation in fluoride dose control, both between different water treatment works and over time. Mean fluoride concentrations in the artificially fluoridated supplies ranged from 0.53 (SD 0.47) to 0.93 (SD 0.22) mg F/L and were within the optimal range of 0.7-1.0 mg F/L in 27.7%-77.8% of samples. The naturally fluoridated supplies had a higher mean fluoride concentration of 1.06 (SD 0.18) and 1.15 (SD 0.16) mg F/L than the artificially fluoridated supplies, with lower variation over time. The naturally fluoridated supplies were above the optimal range in 75.5% and 53% of samples.

CONCLUSIONS

Assumptions that populations living in areas with a water fluoridation scheme have received optimally fluoridated water (0.7-1.0 mg F/L) are invalid. To support future research endeavours, as well as to provide 'external control' and facilitation of optimal dosing, it is recommended that a quarterly record of water fluoride concentrations (mean, standard deviation and minimum and maximum) are made available for every water supply in England, in a format that can be mapped against residential postcodes.

Dental caries experience in children of a remote Australian Indigenous community following passive and active preventive interventions

Objectives

To report on changes in dental caries experience in children of a remote Indigenous community following 6 years of passive preventive intervention (PPI) and 2 years of active preventive intervention (API).

Methods

Five consecutive cross‐sectional surveys were conducted on 4‐ to 15‐year‐old school going children between 2004 and 2017 following phases of Community Water Fluoridation (CWF), post‐cessation of CWF and API. Following treatment of any cavities present, API included selective placement of fissure sealants (FS) and an annual application of povidone‐iodine (PI) and fluoride varnish (FV). The World Health Organization's (WHO) “Oral Health Surveys – Basic Methods (4th Edition)” methodology was used in the first two and the International Caries Detection and Assessment System (ICDAS‐II) in the latter three surveys. ICDAS‐II codes of 3‐6, representing advanced caries, were combined to allow comparison to the decayed component of the DMF caries index.

Results

Age‐weighted mean dmft decreased by 37.7% in the deciduous (DD) and DMFT by 35% in the permanent (PD) dentitions between the pre‐ and post‐CWF surveys, followed by increases of 25% and 7.7%, respectively, between the 1‐year and 4‐year post‐CWF surveys. After 2 years of API, mean dmft decreased by 14.3% and DMFT by 7.1%. Untreated dental caries however remained a concern in the DD and PD during both phases of PPI and of API. The decline in caries experience for both dentitions following 2 years of API exceeded that for the 6‐year period of PPI.

Conclusions

The annual reductions in caries experience of 7.2% (DD) and 8% (PD) during the phase of API exceeded annual decreases of 4.7% (DD) and 4.6% (PD) during the phase of PPI. Due to remoteness, cost and logistics in ensuring long‐term viability of API programmes, CWF remains necessary in this type of community.

"Setting the scene in early childhood" - an MID approach for life

This article presents a discussion paper for both consideration and implementation of Minimal Intervention Dentistry (MID) principles by the general dental practitioner. It argues that if these concepts can be adopted in early childhood by both the community and the profession, "Teeth for Life" can become a reality for all. Oral Health promoting behaviours can be nurtured and supported from infancy and developed into everyday living practice for a lifetime thereby maintaining an optimal quality of life. MID techniques have become more refined and supported by scientific research in the recent times and should be considered an essential clinical guideline for the future disease management.

Reduction of Dental Caries Among Children and Adolescents From a 15-Year Community Water Fluoridation Program in a Township Area, Korea

Since 2000, a community water fluoridation program (CWFP) has been implemented in Hapcheon for over 15 years. We aimed to evaluate the caries-reducing effect on permanent teeth after this implementation. In 2015, evaluation surveys were conducted by our study group, 498 subjects aged 8, 10, 12, and 15 years. As the control, 952 similarly aged subjects were selected from the Sixth Korean National Health and Nutrition Examination Survey (2013-2015 KNHANES). Data of a prospective cohort of 671 8-,10- and 12-year-olds, collected when CWFP started, were used for the evaluation. Caries-reducing effects were estimated by decayed, missing and filled teeth (DMFT) scores between CWFP and control groups, pre- and post-program. Confounders including the mean number of sealant teeth and gender were adjusted for. The mean adjusted DMFT scores of 10-, 12- and 15-year-olds in Hapcheon were significantly lower compared to KNHANES DMFT scores; in addition, those of 8-, 10- and 12-year-olds after the 15-year CWFP were significantly lower than in 2000. The caries-reducing effect among 12-year-olds was 37.6% compared to those recorded in KNHANES, and 67.4% compared to those in 2000. In conclusion, the caries-reducing effect was so high that health policy makers should consider CWFP as a priority policy for caries-reducing in Korean children and adolescents.

The relationship of primary care providers to dental practitioners in rural and remote Australia

Background

Rural residents have poorer oral health and more limited access to dental services than their city counterparts. In rural communities, health care professionals often work in an extended capacity due to the needs of the community and health workforce shortages in these areas. Improved links and greater collaboration between resident rural primary care and dental practitioners could help improve oral health service provision such that interventions are both timely, effective and lead to appropriate follow-up and referral. This study examined the impact oral health problems had on primary health care providers; how primary care networks could be more effectively utilised to improve the provision of oral health services to rural communities; and identified strategies that could be implemented to improve oral health.

Methods

Case studies of 14 rural communities across three Australian states. Between 2013 and 2016, 105 primary and 12 dental care providers were recruited and interviewed. Qualitative data were analysed in Nvivo 10 using thematic analysis. Quantitative data were subject to descriptive analysis using SPSSv20.

Results

Rural residents presented to primary care providers with a range of oral health problems from “everyday” to “10 per month”. Management by primary care providers commonly included short-term pain relief, antibiotics, and advice that the patient see a dentist. The communication between non-dental primary care providers and visiting or regional dental practitioners was limited. Participants described a range of strategies that could contribute to better oral health and oral health oral services in their communities.

Conclusions

Rural oral health could be improved by building oral health capacity of non-dental care providers; investing in oral health promotion and prevention activities; introducing more flexible service delivery practices to meet the dental needs of both public and private patients; and establishing more effective communication and referral pathways between rural primary and visiting/regional dental care providers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12913-017-2473-z) contains supplementary material, which is available to authorized users.

Critique of the review of 'Water fluoridation for the prevention of dental caries' published by the Cochrane Collaboration in 2015

The Cochrane Review on water fluoridation for the prevention of dental caries was published in 2015 and attracted considerable interest and comment, especially in countries with extensive water fluoridation programmes. The Review had two objectives: (i) to evaluate the effects of water fluoridation (artificial or natural) on the prevention of dental caries, and (ii) to evaluate the effects of water fluoridation (artificial or natural) on dental fluorosis. The authors concluded, inter alia, that there was very little contemporary evidence, meeting the Review's inclusion criteria, that evaluated the effectiveness of water fluoridation for the prevention of dental caries. The purpose of this critique is to examine the conduct of the above Review, and to put it into context in the wider body of evidence regarding the effectiveness of water fluoridation. While the overall conclusion that water fluoridation is effective in caries prevention agrees with previous reviews, many important public health questions could not be answered by the Review because of the restrictive criteria used to judge adequacy of study design and risk of bias. The potential benefits of using wider criteria in order to achieve a fuller understanding of the effectiveness of water fluoridation are discussed.

Access to Fluoridated Water and Adult Dental Caries

Systematic reviews have found no evidence to support a benefit of water fluoridation (WF) to prevent dental caries in adult populations. The aim of this natural experiment was to investigate whether lifetime access to fluoridated water is associated with dental caries experience among adults from Florianópolis, Brazil. The data originated from a population-based cohort study ( EpiFloripa Adult) initiated in 2009 ( n = 1,720) when participants were aged 20 to 59 years. The second wave was carried out in 2012 ( n = 1,140) and included a dental examination and a face-to-face questionnaire. Participants residing at the same address since the age of 7 y or before were included in the primary analyses. Sensitivity analyses were also performed. WF was implemented in the city in 2 different periods of time: 1982 (60% of the population) and 1996. Dental caries was assessed by the decayed, missing, and filled teeth (DMFT) index. A combination of residential status, participant’s age, and year of implementation of WF permitted the creation of participants’ lifetime access to fluoridated water: >75%, 50% to 75%, and <50% of a participant’s lifetime. Covariates included sex, age, socioeconomic mobility, educational attainment, income, pattern of dental attendance, and smoking. Participants who accessed fluoridate water <50% of their lifetime presented a higher mean rate ratio of DMFT (1.39; 95% CI, 1.05–1.84) compared with those living >75% of their lifetime with residential access to fluoridated water. Participants living between 50% and 75% and <50% of their lives in fluoridated areas presented a decayed and filled teeth mean ratio of 1.34 (95% CI, 1.02–1.75) and 1.47 (95% CI, 1.05–2.04) higher than those with residential access to fluoridated water >75% of their lifetime, respectively. Longer residential lifetime access to fluoridated water was associated with less dental caries even in a context of multiple exposures to fluoride.

Non-dental primary care providers' views on challenges in providing oral health services and strategies to improve oral health in Australian rural and remote communities: a qualitative study

OBJECTIVES

To investigate the challenges of providing oral health advice/treatment as experienced by non-dental primary care providers in rural and remote areas with no resident dentist, and their views on ways in which oral health and oral health services could be improved for their communities.

DESIGN

Qualitative study with semistructured interviews and thematic analysis.

SETTING

Four remote communities in outback Queensland, Australia.

PARTICIPANTS

35 primary care providers who had experience in providing oral health advice to patients and four dental care providers who had provided oral health services to patients from the four communities.

RESULTS

In the absence of a resident dentist, rural and remote residents did present to non-dental primary care providers with oral health problems such as toothache, abscess, oral/gum infection and sore mouth for treatment and advice. Themes emerged from the interview data around communication challenges and strategies to improve oral health. Although, non-dental care providers commonly advised patients to see a dentist, they rarely communicated with the dentist in the nearest regional town. Participants proposed that oral health could be improved by: enabling access to dental practitioners, educating communities on preventive oral healthcare, and building the skills and knowledge base of non-dental primary care providers in the field of oral health.

CONCLUSIONS

Prevention is a cornerstone to better oral health in rural and remote communities as well as in more urbanised communities. Strategies to improve the provision of dental services by either visiting or resident dental practitioners should include scope to provide community-based oral health promotion activities, and to engage more closely with other primary care service providers in these small communities.

Does lower lifetime fluoridation exposure explain why people outside capital cities have poor clinical oral health?

BACKGROUND

Australians outside state capital cities have greater caries experience than their counterparts in capital cities. We hypothesized that differing water fluoridation exposure was associated with this disparity.

METHODS

Data were the 2004-06 Australian National Survey of Adult Oral Health. Examiners measured participant decayed, missing and filled teeth and DMFT Index, and lifetime fluoridation exposure was quantified. Multivariable linear regression models estimated differences in caries experience between capital city residents and others, with and without adjustment for fluoridation exposure.

RESULTS

There was greater mean lifetime fluoridation exposure in state capital cities (59.1%, 95% confidence interval = 56.9, 61.4) than outside capital cities (42.3, confidence interval = 36.9, 47.6). People located outside capital city areas had differing sociodemographic characteristics and dental visiting patterns, and a higher mean DMFT (capital cities = 12.9, non-capital cities = 14.3, p = 0.02), than people from capital cities. After adjustment for sociodemographic characteristics and dental visits, DMFT of people living in capital cities was less than non-capital city residents (regression coefficient = 0.8, p = 0.01). The disparity was no longer statistically significant (regression coefficient = 0.6, p = 0.09) after additional adjustment for fluoridation exposure.