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Tooth decay gradually declining in New Zealand

Source: Roy Morgan Single Source (New Zealand), July 2013 - June 2014 n=2,017, Base: New Zealanders 14+;
Roy Morgan Single Source (Australia), July 2013 - June 2014 n=2,596, Base: Australians 14+

Between July 2009 and June 2014, the proportion of New Zealanders 14+ with tooth decay decreased from 17.5% to 16.6% — not quite as large a decline as across the Tasman, but good news nonetheless. The greatest drop occurred among young Kiwis aged between 14 and 17, with only 4.0% reporting tooth decay in the 12 months to June 2014, down from 8.1% as of June 2010. Among Maoris and people in the lower socioeconomic groups, however, it remains more prevalent.

There were also noticeable declines in incidence of tooth decay among the 18-24 and 25-34 age groups over the same period: the former falling from 11.4% to 10.5%, and the latter from 19.8% to 16.4%. The incidence of tooth decay grew slightly among Kiwis aged 65 and older.

All age groups except teenagers under 18 are more likely than their Australian peers to have tooth decay.

Tooth decay incidence by age: New Zealand vs Australia


Source: Roy Morgan Single Source (New Zealand), July 2013 - June 2014 n=2,017, Base: New Zealanders 14+; Roy Morgan Single Source (Australia), July 2013 - June 2014 n=2,596, Base: Australians 14+

As they were the last time we reported on New Zealand dental health, Maoris remain the ethnic group at highest risk of tooth decay, with 20.8% reporting they had tooth decay in the year to June 2014. They were followed by Kiwis from European backgrounds (17.0%), Pacific Islanders (15.0%) and people of Asian descent (8.2%).

Of course, lifestyle choices can also contribute to a person’s dental health, and our findings show that Kiwis who drink more than three or four glasses of cola and/or cordial per week run a greater risk of having tooth decay. Smokers and people who eat fast food more than once a month are also more likely than the average New Zealander to have tooth decay.

Pip Elliott, General Manager, Roy Morgan Research NZ, says:

“The low rate of tooth decay among young teenagers in New Zealand suggests that the government’s extensive dental care subsidies for Kiwis under 18 are having a positive effect. However, among adult New Zealanders, incidence of tooth decay seems to rise with age, hitting a peak among those between 50 and 64 years.

“Although many low-income earners with community service cards qualify for government subsidies on basic and emergency dental care, tooth decay is more prevalent among people from lower socio-economic sectors of the population than their more affluent counterparts.

“For example, when we analyse incidence of tooth decay in New Zealand using Roy Morgan’s in-depth profiling tool Helix Personas, we see that individuals from the Strugglestreet and Provincial Families personas (both of which form part of the cash-strapped Battlers community) are much more likely to have tooth decay than the average Kiwi.

“Typically comprised of young families and single parents, Strugglestreet are often unemployed and (as their name suggests) struggling financially. Though their kids are generally young enough to be covered for dental treatment, a tight budget means that their own dental needs take a backseat to other more pressing household expenses. 

“Spanning a wider range of ages and often Maori, Provincial Families earn well below the average income, and are more concerned with making the rent than paying for a trip to the dentist.”

For comments or further detail, please contact:
John La Rosa, General Manager Agencies
Office: +61 (02) 9021 9115

About Roy Morgan

Roy Morgan is the largest independent Australian research company, with offices throughout Australia, as well as in Indonesia, the United States and the United Kingdom. A full service research organisation specialising in omnibus and syndicated data, Roy Morgan has over 70 years’ experience in collecting objective, independent information on consumers.

Margin of Error

The margin of error to be allowed for in any estimate depends mainly on the number of interviews on which it is based. Margin of error gives indications of the likely range within which estimates would be 95% likely to fall, expressed as the number of percentage points above or below the actual estimate. Allowance for design effects (such as stratification and weighting) should be made as appropriate.

Sample Size

Percentage Estimate


25% or 75%

10% or 90%

5% or 95%