A quarter of all Australian children aged 10 and under has untreated tooth decay.

The National Child Oral Health Survey 2012-2014 is the first population-based study of its kind in Australia for 25 years, involving data from more than 24,000 children aged 5-14 years in each state and territory.

“This study is one of the biggest and most comprehensive of its kind in the world, giving us important and timely insights into the trends occurring in child oral health and behaviours of Australian children and their families,” says the University of Adelaide's Associate Professor Loc Do.

“We found that tooth decay affected a significant proportion of children: over 40 per cent of children aged 5-10 years had decay in their primary (baby) teeth. One quarter of children in that same age group had never received treatment for their tooth decay. On average, Australian children aged 5-10 had 1.5 primary teeth with decay,” he says.

“More than one third of children aged 9-14 years had decay in their permanent teeth, and one in seven children in this age group had not previously been treated for decay in permanent teeth.

“The prevalence of tooth decay was similar to other comparable countries, such as the United States and New Zealand, but the prevalence of untreated decay was somewhat higher in Australia,” he says.

Associate Professor Do says the results vary depending on state and territory and socio-economic status of the child's family.

“Children from Queensland and from the Northern Territory had the highest prevalence and severity of tooth decay. Data in Queensland was collected at the start of the expansion of water fluoridation and the start of the survey (2010-12), so it was too early to see the positive impact of drinking water fluoridation, as that is likely to be emerging only now,” he says.

“Children of low socio-economic background and Indigenous children had significantly higher rates of dental decay, unfavourable dental and general health behaviours, and unfavourable dental visiting patterns.”

The study showed that although the National Oral Health Plan’s target was for 100 per cent of children to see a dentist, one in nine children had never made a dental visit.

“Significantly more children in the lowest income households had unfavourable dental attendance. This income-related gap in dental visiting patterns has widened over time.

“We would like to see regular dental check-ups as a matter of course, to help children and their families to prevent tooth decay and treat oral health problems promptly,” he says.

This research will be available to the public soon.