Early studies of community water fluoridation showed an important effect on prevention of tooth decay in children. Recent studies show smaller effects.Any potential oral health benefits should be comprehensively considered alongside potential harms and costs (taking contemporary effect estimates into account).There is inconsistent evidence with regards to the impact of water fluoridation on oral health inequalities.Where community water fluoridation is implemented, monitoring of water fluoride concentrations is critical to ensure schemes consistently provide optimal potential benefits in terms of caries prevention.