Just looking at some of the evidence, where does fluoridation come in? Back in 2014, the Office of the Prime Minister's Chief Science Advisor and the Royal Society of New Zealand undertook a review of the scientific evidence of the health effects of fluoridation. What they concluded was "from a medical and public health perspective, water fluoridation at the levels used in New Zealand poses no significant health risks and is effective at reducing the prevalence and severity of tooth decay in communities where it is used." And they were very reassuring that, for communities that weren't fluoridated in terms of their water supplies, that they could be confident that this was a safe option and it would save significant costs in terms of dental health issues—particularly for those that are experiencing quite high levels of dental caries. 