In the last week, Windsor in Ontario, Canada, voted to reinstate community water fluoridation (CWF) 5 years after it was stopped because of opposition.
This time the City Council was swayed by the Windsor-Essex County Health Unit’s Oral Health 2018 Report which found the percentage of children with tooth decay or requiring urgent care increased by 51 per cent since fluoridation had stopped.
Now a new study reports similar increases in child tooth decay after stopping CWF in the Alaskan capital, Juneau. This paper reports the study results for Juneau:
Meyer, J., Maragaritis, V., & Mendelshon, A. (2018). Consequences of community water fluoridation cessation for Medicaid-eligible children and adolescents in Juneau, Alaska. BMC Oral Health, 18:215
Juneau – an ideal community for the study
Juneau maintains all the modern conveniences and standards expected of a capital city but has little in-and-out migration or travel from neighbouring countries as it is accessible only by plane or sea. This reduces confounding effects due to population changes, only about 0.006% per year during the study period.
Use of fluoridated toothpaste is widespread and CWF was available to 96% of residents before it was stopped in January 2007.
The researchers compared child oral health data in 2003 (when children were exposed to optimum levels of fluoride: 0.7 – 1.2 mg/L) with that in 2012, 6 years after CWF ceased. During those six years, exposure to fluoride was suboptimum: <0.065 mg/L.
The data used for the study was from Medicaid dental claims records. This means the study population was made up of residents living at near poverty conditions. This limited confounding effects from higher-income groups.
Cessation of CWF resulted in increased child tooth decay
The findings were clear and statistically significant. The number of caries-related dental procedures increased after cessation of CWF.
For all children and adolescents (ages 0 – 18 years) the number of procedures increased by 16%. But binary logistic results indicated “the odds of a child or adolescent undergoing a dental caries procedure in 2003 was 25.2% less than that of a child or adolescent in the suboptimal CWF group.”
The effects of CWF were even greater for children aged 0 – 6 years who had never experienced the advantages of exposure optimum fluoride levels. The number of caries-related dental procedures in this group increased by 63%. However, binary logistic results indicated “the odds of undergoing dental caries procedures under optimal CWF conditions was 51% less than that for a child of the same age in 2012 under suboptimal conditions.”
CWF cessation increased dental treatment costs
The researchers obtained dental costs from the Medicaid dental claims records so were able to make estimates of the effects of CWF on the financial costs to the community. After adjusting for inflation this data showed that the increased annual cost per person of ages 0 – 18 years due to cessation of CWF increased by $162, a 47% increase. The corresponding increase for children 0 – 6 years was $303, a 111% increase.
While this study had several advantages over similar studies because of reduced confounding effects due to migration and socioeconomic factors this may also be seen as a limitation when trying to extend to findings to more socially heterogeneous communities. However, the authors conclude it does provide strong evidence supporting:
“current evidence that even in modern conditions with widely available fluoride toothpaste, rinses, and professionally applied prophylaxis, CWF is associated with population benefits, including cost effectiveness and caries prevention.”
They also conclude from their results that:
“CWF cessation promoted a marked increase in the number of caries-related procedures and treatment costs for Medicaid-eligible children and adolescents aged 0–18 years. Additionally, the results indicated that children in the younger age group cohorts underwent more dental caries procedures than the older age group cohorts, who had benefited from early childhood exposure to optimal CWF.”