Methodological considerations for designing a community water fluoridation cessation study

High-quality, up-to-date research on community water fluoridation (CWF), and especially on the implications of CWF cessation for dental health, is limited. Although CWF cessation studies have been conducted, they are few in number; one of the major reasons is the methodological complexity of conducting such a study. This article draws on a systematic review of existing cessation studies (n=15) to explore methodological considerations of conducting CWF cessation studies in future. We review nine important methodological aspects (study design, comparison community, target population, time frame, sampling strategy, clinical indicators, assessment criteria, covariates and biomarkers) and provide recommendations for planning future CWF cessation studies that examine effects on dental caries. There is no one ideal study design to answer a research question. However, recommendations proposed regarding methodological aspects to conduct an epidemiological study to observe the effects of CWF cessation on dental caries, coupled with our identification of important methodological gaps, will be useful for researchers who are looking to optimize resources to conduct such a study with standards of rigour.