Water fluoridation less effective now than in past
The same contemporary studies (conducted after 1975) also looked at the number of children with no decay in their baby teeth. The analysis found that fluoridation may increase the number of children with no tooth decay by 3 percentage points, again with the possibility of no benefit.
The review was only able to draw conclusions about the impact on children’s teeth, with similar findings across both baby and permanent teeth. There were no studies with adults that met the review’s criteria.
“The evidence suggests that water fluoridation may slightly reduce tooth decay in children” says co-author Dr Lucy O’Malley, Senior Lecturer in Health Services Research at the University of Manchester. “Given that the benefit has reduced over time, before introducing a new fluoridation scheme, careful thought needs to be given to costs, acceptability, feasibility and ongoing monitoring.”
Advocates have suggested that one of the key benefits of water fluoridation is that it reduces oral health inequalities. This updated review sought to examine this question and did not find enough evidence to support this claim, although this doesn’t necessarily mean there is no effect.
The review’s findings accord with recent observational studies including the LOTUS study, which compared anonymised dental health records with water fluoridation status for 6.4 million adults and adolescents in England between 2010 and 2020. People in fluoridated areas needed slightly fewer invasive dental treatments with no significant impact on inequalities.
“Contemporary evidence using different research methodologies suggest that the benefits of fluoridating water have declined in recent decades,” says Tanya Walsh, Professor of Healthcare Evaluation at the University of Manchester, co-author on both the Cochrane review and the LOTUS study. “Oral health inequalities are an urgent public health issue that demands action. Water fluoridation is only one option and not necessarily the most appropriate for all populations”.
“Whilst water fluoridation can lead to small improvements in oral health, it does not address the underlying issues such as high sugar consumption and inadequate oral health behaviours” says co-author Janet Clarkson, Professor of Clinical Effectiveness, University of Dundee. “It is likely that any oral health preventive programme needs to take a multi-faceted, multi-agency approach.”
