Fluoridation of the water supply may confer a modest benefit to the dental health of children, a seven-year study led by UK researchers has concluded.
However, the benefits are smaller than shown in previous studies—carried out 50 years ago—when fluoride toothpaste was less widely available in the UK.
The research—published in the journal Public Health Research—was led by a team from the University of Manchester’s Division of Dentistry, and is the first contemporary study of the effects of initiation of a water fluoridation scheme in the UK since fluoride toothpaste became widely available in the 1970s.
The study also showed it was likely that water fluoridation was a cost-effective way to help reduce some of the £1.7 billion a year the NHS spends on dental caries.
The study assessed the dental health of two cohorts of young children over a six-year period in West Cumbria—where water fluoridation was reintroduced in 2013, and the rest of Cumbria, which remains fluoride free.
In West Cumbria, the younger cohort were born after water fluoridation was introduced (this meant they had the full effect of water fluoridation).
The older cohort was aged around five when fluoride was reintroduced into the water supply—which meant they mainly received the benefit for those teeth already in the mouth.
Dental teams carried out examinations on the children at regular intervals and took images of their teeth which were blinded to the fluoridation status of each participant to remove bias.
They also collected information about the children’s diet, brushing habits and dental attendance.
In the younger cohort, 17.4 per cent of the children in fluoridated areas had decayed, filled or missing milk teeth; the number was 21.4 per cent for children in non-fluoridated areas, amounting to a modest four per cent reduction in incidence of caries.
In the older cohort, 19.1 per cent of the children in fluoridated areas had decayed, filled or missing permanent teeth; the number was 21.9 per cent for children in non-fluoridated areas.
There was insufficient evidence as to whether water fluoridation prevents decay in older children with a difference of 2.8 per cent.
“While water fluoridation is likely to be cost-effective and has demonstrated an improvement in oral health, it should be carefully considered along with other options, particularly as the disease becomes concentrated in particular groups,” senior investigator Dr Michaela Goodwin said.
