Equity in children's dental caries before and after cessation of community water fluoridation: differential impact by dental insurance status and geographic material deprivation

Community water fluoride cessation and rate of caries-related pediatric dental treatments under general anesthesia in Alberta, Canada

OBJECTIVE

This study examined the rate of caries-related dental treatments under general anesthesia (GA) in fluoridated and non-fluoridated communities in Alberta, Canada, between 2010 and 2019.

METHODS

This retrospective, population-based study included all children ( < 12 years of age) living in Calgary (non-fluoridated) and Edmonton (fluoridated) who underwent caries-related dental treatments under GA at publicly funded facilities. Demographics and dental data were extracted from health administrative databases for three time periods of 2010/11 (pre-cessation), 2014/15, and 2018/19 (post-cessation).

RESULTS

Among 2659 children receiving caries-related treatments under GA, the mean (SD) and median (IQR) age were 4.8 (2.3) and 4 (3-6) years, respectively, and 65% resided in the non-fluoridated area. The analysis revealed that the cessation of water fluoridation was significantly associated with an increased rate of caries-related GA events per 10,000 children in both age groups (0-5 and 6-11 years), with a more pronounced effect in 0-5-year-olds in non-fluoridated areas. The risk of dental treatments under GA was also positively associated with post-cessation time.

CONCLUSION

Discontinuing water fluoridation appears to negatively affect young children's oral health, potentially leading to a significant increase in caries-related dental treatments under GA and oral health disparities in this pediatric population.

Fluoridation cessation and oral health equity: a 7-year post-cessation study of Grade 2 schoolchildren in Alberta, Canada

OBJECTIVE

Community water fluoridation, because of its universal scope and passive mechanism of uptake, is one component of a multifaceted approach to promoting equity in dental health. The objective of this study was to examine social inequities in children's dental health in the Canadian cities of Calgary (fluoridation cessation in 2011) and Edmonton (still fluoridated).

METHODS

We analyzed data from surveys of population-based samples of Grade 2 (approx. age 7) children in Calgary in 2009/2010 (pre-cessation; n=557) and in both Calgary and Edmonton in 2013/2014 (Calgary, n=3230; Edmonton, n=2304) and 2018/2019 (Calgary, n=2649; Edmonton, n=2600) (post-cessation). We estimated associations between several socioeconomic indicators and dental caries indicators (i.e., dental caries experience [deft, DMFT] and untreated decay in two or more teeth [untreated decay]) using zero-inflated Poisson, binary logistic regression, and the concentration index of inequality. We compared those associations over time (between survey waves) and between cities at post-cessation.

RESULTS

Persistent social inequities in deft and untreated decay were evident; for example, having no dental insurance was significantly associated with higher odds of untreated decay across city and survey wave. In most (but not all) cases, differences between cities and survey waves were consistent with an adverse effect of fluoridation cessation on dental health inequities. For example, the association between no dental insurance and higher odds of untreated decay in Calgary was greater in 2018/2019 (later post-cessation) than in 2009/2010 (pre-cessation; odds ratio [OR] for comparison of coefficients = 1.89 [1.36-2.63], p<0.001) and 2013/2014 (early post-cessation; OR for comparison of coefficients = 1.67 [1.22-2.28], p=0.001); that same association in 2018/2019 was greater in Calgary (fluoridation cessation) than in Edmonton (still fluoridated) (OR for comparison of coefficients = 1.44 [1.03-2.02], p=0.033).

CONCLUSION

Social inequities in dental caries were present in both Calgary and Edmonton. Those inequities tended to be worse in Calgary where fluoridation was ceased. Our findings may be relevant to other settings where income inequality is high, dental services are costly, and dental public health infrastructure is limited.

The Impact of Water Fluoridation on Medicaid-Eligible Children and Adolescents in Alaska

Juneau, Alaska, ceased community water fluoridation (CWF) in 2007, and previous research found a substantial increase in dental caries-related procedures and treatment costs for children from low-income families in Juneau between 2003 and 2012. We collected comparable dental caries-related procedures and treatment cost data for the same years for children in Anchorage, Alaska, where CWF has been continuously maintained. This retrospective study analyzed all Medicaid dental claims records in two separate years for caries-related procedures and associated costs among children (aged 0 to 18 years) residing in Anchorage's 99502 zip code and compared these records to data from Juneau. We obtained descriptive statistics and conducted bivariate analyses and binomial logistic regression. Between 2003 and 2012, children in Anchorage experienced a nonsignificant modest decrease in the mean number of caries-related procedures and only small, statistically nonsignificant changes to the mean inflation-adjusted service costs of caries-related restorative care. The lack of significant change in child dental caries-related procedures and treatment costs in Anchorage between 2003 and 2012 contrasted with the substantial increase in caries-related procedures and treatment costs over the same period in Juneau. Our results are consistent with previous research that has demonstrated a significant protective effect of CWF against dental caries.

Neighborhood Contexts and Oral Health Outcomes in a Pediatric Population: An Exploratory Study

Aims: This study aimed to explore the impacts of neighborhood-level socioeconomic contexts on the therapeutic and preventative dental quality outcome of children under 16 years. Materials and Methods: Anonymized billing data of 842 patients reporting to a university children’s dental over three years (March 2017–2020) met the inclusion criteria. Their access to care (OEV-CH-A), topical fluoride application (TFL-CH-A) and dental treatment burden (TRT-CH-A) were determined by dental quality alliance (DQA) criteria. The three oral health variables were aggregated at the neighborhood level and analyzed with Canadian census data. Their partial postal code (FSA) was chosen as a neighborhood spatial unit and maps were created to visualize neighborhood-level differences. Results: The individual-level regression models showed significant negative associations between OEV-CH-A (p = 0.027) and TFL-CH-A (p = 0.001) and the cost of dental care. While there was no significant association between neighborhood-level sociodemographic variables and OEV-CH-A, TRT-CH-A showed a significant negative association at the neighborhood level with median household income and significant positive association with percentage of non-official first language (English or French) speakers. Conclusion: Initial analysis suggests differences exist in dental outcomes according to neighborhood-level sociodemographic variables, even when access to dental care is similar.

Fluoridation cessation and children's dental caries: A 7-year follow-up evaluation of Grade 2 schoolchildren in Calgary and Edmonton, Canada

Objectives

We examined the effect of fluoridation cessation on children's dental caries experience in the Canadian cities of Calgary (cessation in 2011) and Edmonton (still fluoridated).

Methods

We used a pre‐post cross‐sectional design with comparison group. We studied Grade 2 schoolchildren (approximately 7 years old) 7‐8 years after fluoridation cessation in Calgary, thus capturing children born after cessation occurred. Data collection included a dental examination conducted in school by calibrated dental hygienists, a questionnaire completed by parents, and fingernail clippings for a small subsample. Our overall analytic approach was twofold. We first examined differences in dental caries experience (deft and DMFT, and smooth surface caries based on defs and DMFS) between Calgary and Edmonton and over time (comparing 2018/2019 data to pre‐cessation and early post‐cessation surveys in our setting). Second, we evaluated whether differences were likely to reflect fluoridation cessation in Calgary, rather than other factors.

Results

The prevalence of caries in the primary dentition was significantly higher (P < .05) in Calgary (fluoridation cessation) than in Edmonton (still fluoridated). For example, crude deft prevalence in 2018/2019 was 64.8% (95% CI 62.3‐67.3), n = 2649 in Calgary and 55.1% (95% CI 52.3‐57.8), n = 2600 in Edmonton. These differences were consistent and robust: they persisted with adjustment for potential confounders and in the subset of respondents who were lifelong residents and reported usually drinking tap water; they had widened over time since cessation; and they were corroborated by assessments of dental fluorosis and estimates of total fluoride intake from fingernail clippings. Findings for permanent teeth were less consistent, which likely reflects that 7‐year‐olds have not had the time to accumulate enough permanent dentition caries experience for differences to have become apparent.

Conclusions

Our findings are consistent with an adverse impact of fluoridation cessation on children's dental health in Calgary and point to the need for universal, publicly funded prevention activities—including but not limited to fluoridation.

Systematic Review of Intervention Studies Aiming at Reducing Inequality in Dental Caries among Children

(1) Background: The objective is to systematically review the evidence on intervention programs aiming at reducing inequality in dental caries among children. (2) Methods: Two independent investigators searched MEDLINE, Cochrane library, and Ovid up to December 2020 to identify intervention studies assessing the impact on socioeconomic inequalities in dental caries among children. The interventions included any health promotion/preventive intervention aiming at reducing caries among children across different socioeconomic groups. Comparison groups included children with alternative or no intervention. Cochrane criteria were used to assess interventional studies for risk of bias. (3) Results: After removal of duplicate studies, 1235 articles were retained. Out of 43 relevant papers, 13 articles were identified and used in qualitative synthesis, and reported quantifiable outcomes. The included studies varied in measurements of interventions, sample size, age groups, and follow-up time. Five studies assessed oral health promotion or health-education, four assessed topical fluorides, and four assessed water fluoridation. Interventions targeting the whole population showed a consistent reduction of socioeconomic inequalities in dental caries among children. (4) Conclusion: The quality of included papers was moderate. High heterogeneity did not allow aggregation of the findings. The overall findings suggest that whole population interventions such as water fluoridation are more likely to reduce inequalities in children’s caries than target population and individual interventions.

Strengthening the approach to oral health policy and practice in Canada

Evidence suggests that Canadian children from marginalized populations experience higher rates of oral diseases than their more fortunate counterparts. Oral health care in Canada is a nearly exclusively privatized and siloed system. In order to close the gap in child oral health, a combination of cohesive strategies and accessible providers is essential. The Health Impact Pyramid is a paradigm to guide health policy and programming with ready application to oral health care in Canada for the delivery of evidence-based oral health interventions with high impact. A collaborative approach among primary care providers (oral health and nonoral health), educators and the public sector, and the utilization of oral health service providers to their full scope of practice is needed to access priority populations and to deliver the most impactful interventions. Strengthening the approach to oral health care in Canada is necessary to reduce the inequities in oral health and, in turn, overall child health.

In defense of a population-level approach to prevention: why public health matters today

A focus on populations, and a corresponding population-level approach to intervention, is a foundation of public health and is one reason why public health matters today. Yet, there are indications that this foundation is being challenged. In some policy and practice domains, and alongside growing concern about the social determinants of health and health equity, there has been a shift from a population-level or universal approach to intervention, to a targeted approach focusing on those experiencing social or economic vulnerability. More than 30 years ago, Geoffrey Rose articulated strengths and limitations of population-level and high-risk approaches to prevention. In light of a strong analogy between "high risk" and "targeted" approaches, it seems timely, in a forum on why public health matters today, to revisit Rose's points. Focusing on points of overlap between strengths and limitations of the two approaches as described in public health (population-level; high-risk) and social policy (universal; targeted), I illustrate strengths of a population-level approach from the point of view of health equity. Although different circumstances call for different intervention approaches, recent discourse about the weakening of public health suggests that there is value in discussing foundations of the field, such as the population-level approach, that we as a community may wish to defend.

Identifying and critically examining government legislation relevant to children's dental caries in Calgary, Alberta, Canada: a health inequities lens

Objectives

Children's dental caries is an important and urgent public health concern that is largely preventable. Using a social equity framework, our objectives were to identify and critically examine government legislation relevant to the issue of children's dental health in Calgary, Alberta, Canada.

Methods

We conducted a systematic, gray literature search of federal, provincial (Alberta), and municipal (Calgary) statutes and bylaws related to children's dental caries, through the relevant law databases. Eligibility criteria were applied for document screening and selection. Data extraction and synthesis pertained to objectives of the legislation (policy task), relevant agent or actor (level of government), and upstream or downstream focus, in terms of potential impact on social inequities in health.

Results

Legislation (n = 114) was retrieved and grouped into eight policy tasks. Most legislation fit under the policy tasks: protection of public safety and health promotion (n = 40) and benefits and compensation (n = 27). Federal and provincial governments have greater involvement in children's dental caries than municipal (Calgary) government. The majority of legislation was classified as upstream in orientation (e.g., improving living and working conditions; macro‐level policies).

Conclusions

Analysis of legislation relevant to children's dental caries reveals policies that are more often upstream in nature, and unsurprisingly are multijurisdictional. Despite this, there remains a high prevalence and inequitable distribution of children's dental caries in Canada. This suggests that the nature of upstream involvement and fragmented government involvement is ineffective in tackling this pervasive and urgent public health issue. Implications for children's dental health are discussed.

Consequences of community water fluoridation cessation for Medicaid-eligible children and adolescents in Juneau, Alaska

BACKGROUND

The general aim of this research was to determine whether cessation of community water fluoridation (CWF) increased oral health disparities, as measured by dental caries procedures and restoration costs for children and adolescents.

METHODS

The analysis was based on all Medicaid dental claims records of 0- to 18-year-old patients residing in zip code 99801 (Juneau, Alaska) during an optimal CWF year (2003, n = 853) compared to all claims for the same age group from 2012 (n = 1052), five years after cessation of CWF. A bivariate analysis (Mann-Whitney U test) of the mean number of caries procedures performed per client was conducted in the study groups under both independent CWF conditions. Furthermore, logistic regression was performed using the dependent variables of caries procedures and the cost of caries-related procedures, with adjustments for CWF group, gender, and race.

RESULTS

The statistically significant results included a higher mean number of caries-related procedures among 0- to 18-year-old and < 7-year-old patients in the suboptimal CWF group (2.35 vs. 2.02, p < 0.001; 2.68 vs. 2.01, p = 0.004, respectively). The mean caries-related treatment costs per patient were also significantly higher for all age groups, ranging from a 28 to 111% increase among the suboptimal CWF cohorts after adjusting for inflation. The binary logistic regression analysis results indicated a protective effect of optimal CWF for the 0- to 18-year-old and < 7-year-old age groups (OR = 0.748, 95% CI [0.62, 0.90], p = 0.002; OR = 0.699, 95% CI [0.52, 0.95], p = 0.02, respectively). Additionally, the age group that underwent the most dental caries procedures and incurred the highest caries treatment costs on average were those born after CWF cessation.

CONCLUSIONS

These results expand our understanding of caries epidemiology under CWF cessation conditions and reaffirm that optimal CWF exposure prevents dental decay. These findings can offer fiscal estimates of the cost burden associated with CWF cessation policies and help decision-makers advance oral health, prevent dental caries, and promote equity in oral health outcomes.

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.

Blood Lead Levels and Dental Caries in U.S. Children Who Do Not Drink Tap Water

INTRODUCTION

This study's purpose is to determine whether nonconsumption of tap water is associated with lower prevalence of elevated blood lead levels and higher prevalence of dental caries in children and adolescents.

METHODS

Cross-sectional data from the National Health and Nutrition Examination Survey 2005-2014 recorded drinking water source (n=15,604) and blood lead levels (n=12,373) for participants aged 2-19 years, and dental caries experience for the 2011-2014 subset (n=5,677). The threshold for elevated blood lead level was ≥3 μg/dL. A binary outcome indicated presence or absence of dental caries experience. Multivariable generalized linear models estimated adjusted prevalence ratios with 95% confidence limits.

RESULTS

In analysis conducted in 2017, 15% of children and adolescents did not drink tap water, 3% had elevated blood lead levels ≥3 μg/dL, and 50% had dental caries experience. Children and adolescents who did not drink water were less likely than tap water drinkers to have an elevated blood lead level (adjusted prevalence ratios=0.62, 95% confidence limits=0.42, 0.90). Nonconsumers of tap water were more likely to have dental caries (adjusted prevalence ratios=1.13, 95% confidence limits=1.03, 1.23). Results persisted after adjustment for other covariates and using a higher threshold for elevated blood lead level.

CONCLUSIONS

In this nationally representative U.S. survey, children and adolescents who did not drink tap water had lower prevalence of elevated blood lead levels and higher prevalence of dental caries than those who drank tap water.

Limitations of fluoridation effectiveness studies: Lessons from Alberta, Canada

A paper published in this journal, "Measuring the short-term impact of fluoridation cessation on dental caries in Grade 2 children using tooth surface indices," by McLaren et al had shortcomings in study design and interpretation of results, and did not include important pertinent data. Its pre-post cross-sectional design relied on comparison of decay rates in two cities: Calgary, which ceased fluoridation, and Edmonton, which maintained fluoridation. Dental health surveys conducted in both cities about 6.5 years prior to fluoridation cessation in Calgary provided the baseline. They were compared to decay rates determined about 2.5 years after cessation in a second set of surveys in both cities. A key shortcoming was the failure to use data from a Calgary dental health survey conducted about 1.5 years prior to cessation. When this third data set is considered, the rate of increase of decay in Calgary is found to be the same before and after cessation of fluoridation, thus contradicting the main conclusion of the paper that cessation was associated with an adverse effect on oral health. Furthermore, the study design is vulnerable to confounding by caries risk factors other than fluoridation: The two cities differed substantially in baseline decay rates, other health indicators, and demographic characteristics associated with caries risk, and these risk factors were not shown to shift in parallel in Edmonton and Calgary through time. An additional weakness was low participation rates in the dental surveys and lack of analysis to check whether this may have resulted in selection biases. Owing to these weaknesses, the study has limited ability to assess whether fluoridation cessation caused an increase in decay. The study's findings, when considered with the additional information from the third Calgary survey, more strongly support the conclusion that cessation of fluoridation had no effect on decay rate. Consideration of the limitations of this study can stimulate improvement in the quality of future fluoridation effectiveness studies.