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