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Fluoridation cessation and children’s dental caries: A 7-year follow-up evaluation of Grade 2 schoolchildren in Calgary and Edmonton, Canada.
Abstract
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.
*Full-text article online at https://onlinelibrary.wiley.com/doi/epdf/10.1111/cdoe.12685
Supporting Information:
cdoe12685-sup-0001-TableS1.docxWord document, 13.8 KB, TABLE S1
Acknowledgements
This study was funded by a research grant from the Canadian Institutes of Health Research (CIHR) (PJT-156258). Dr Lindsay McLaren was supported by an Applied Public Health Chair research award funded by CIHR (Institute of Population & Public Health and Institute of Musculoskeletal Health & Arthritis), the Public Health Agency of Canada, and Alberta Innovates—Health Solutions (CIHR ID CPP-137907). Dr Cynthia Weijs was supported by a CIHR Health System Impact Fellowship, 2017-2020 (Award # 403867). We are grateful to Dr Marília Afonso Rabelo Buzalaf, Professor of Biochemistry and Cariology at the University of São Paulo, for performing the analysis of fluoride concentrations from fingernail samples. We also extend our sincere thanks to the dental hygienists and clerks who worked on the project, and to the participating school boards, schools, and families.
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