The basis for the constitutional challenge to the Health (Fluoridation of Water Supplies) Act 1960 in the Republic of Ireland and the judgements of the High Court and Supreme Court are described. Pre-fluoridation baseline surveys and various surveys conducted over the last 30 years in the Republic of Ireland show, that amongst of fluoridated communities, children experience lower levels of dental caries and adults retain more of their natural teeth when compared with residents of non-fluoridated communities.