Water fluoridation appears to have benefitted the oral health of older people in Ireland, according to a new study.

Currently in Ireland, the public water supply is fluoridated. The practice is considered controversial by some, with anti-fluoridation campaigners arguing that adding substances to the water supply amounts to mass medication, which they insist is unethical.

However, dentists have long claimed that along with fluoride toothpaste, fluoridated water is the most effective way of preventing dental caries (cavities).

This new study was carried out by researchers from the Irish Longitudinal Study on Ageing (TILDA) - an ongoing study of people over the age of 50 - and the School of Dental Science in Trinity College Dublin (TCD).

They set out to investigate the relationship between water fluoridation and oral health in adults over the age of 50 using data from almost 5,000 TILDA participants. They also used the findings from Census 2006 to gather information on the type of water supplies in people's local areas.

According to those 2006 figures, some 84% of households had fluoridated water supplies.

The study found that older people who lived in areas with a higher prevalence of fluoridated households were more likely to still have all their own teeth.

The researchers also looked at the bone density measurements of the participants because it is known that, at a molecular level, fluoride can increase bone mass. However, they found no link between bone density and the prevalence of fluoridated water.

"While the initial focus of water fluoridation in Ireland was to prevent tooth cavities in children, much less attention has been paid to the effects of fluoridation later in life. There are now large adult populations that have lived several decades with fluoridated water supplies, yet the benefits and risks for these populations have remained unclear.

"This study shows a measureable positive relationship between fluoridation and maintaining a person's own teeth," commented Prof Brian O'Connell of the Dublin Dental School and Hospital at TCD.

He acknowledged that there were some limitations to the study. For example, it was not possible to assess the impact of other fluoride sources, such as from toothpaste and mouth rinses, which can also have an impact on overall oral health.

The researchers also acknowledged that while extensive international reviews of water fluoridation have found no clear evidence of toxicity and no detrimental effects on general health, the practice remains controversial and it is therefore essential that the health effects on Irish people be properly investigated.

"The availability of detailed data from TILDA on the health, wellbeing and economic circumstances of a nationally representative sample of the over 50s allows us to undertake a comprehensive investigation of the impact of public health policies such as water fluoridation on the health of the older population,' noted TILDA principal investigator, Prof Rose Anne Kenny.

She added that studies such as TILDA are ‘an invaluable resource for tracking trends in population health, investigating the causes and consequences of disease and for assessing the impact of policy on the health and wellbeing of our older population'.

For more information on TILDA, click here