The dental health of young children continues to be among the worst in the developed world, figures reveal.

Forty-four per cent of 5-year-olds have at least one decayed, missing or filled tooth, a school dental services report has found.

The Government has spent $417 million on the problem since 2007 but the figures have shown little improvement.

In 2000, 48 per cent of 5-year-olds had cavities, and the figure has not dropped below 43 per cent since.

New Zealand rates are worse than the UK, US and Australia.

Auckland paediatric dentist Clarence Tam said it wasn't unusual to see children as young as 2 or 3 with huge holes in several teeth.

"It definitely seems to be on the rise for 5-year-olds and younger children. Cavities start to rip through their teeth like wildfire," he said.

The report, by the Ministry of Health, showed the worst hit areas were Counties Manukau, where 11,830 cavities were recorded, followed by Waikato, 9152, and Northland, 7810.

The study showed Maori and Pacific Island 5-year-olds had the worst oral hygiene, with 65 per cent and 73 per cent having one or more decayed, missing or filled teeth respectively.

Free dental care is available for children up to 18. Most public primary schools have a dental clinic and many regions operate mobile clinics.

Despite campaigns to improve access and enrolment, a number of factors led to poor oral hygiene, the ministry said.

Many parents didn't see oral health as a priority and only took their children to a dentist in an emergency, said New Zealand Dental Association spokeswoman Deepa Krishnan.

Tam agreed and said diet was also to blame, with people choosing unhealthy snacks that allowed acid to attack teeth.

"I've seen a baby bottle filled with Coca-Cola. People choose to eat cakes or potato chips as opposed to a slice of cheese, nuts or carrot sticks."

Parents needed to set a good example and get children to brush their teeth at least twice a day and floss, said Tam.

Losing baby teeth early could mean problems as they got older, including a lack of space for adult teeth.

In extreme cases, where most of the baby teeth had to be pulled out, children could be without teeth for several years, said Krishnan.

"Imagine a 2 to 3-year-old with no teeth. They cannot eat, can't bite or chew. They have problems with speaking and it affects their self esteem."

In the US, 28 per cent of children aged between 2 and 5 had one or more decayed, missing or filled teeth in 2004.

In 2005, the figure for 5-year-olds in England was 39 per cent and in Australia 43 per cent.

The Government has allocated $116m to refurbish and build dental clinics, and to buy mobile clinics in the next five years. Another $40m is available each year for community oral health services.

DAUGHTER'S DECAY CAME AS A SHOCK TO CAREFUL MOTHER

Former dental assistant Jenni Graham was shocked to discover her 4-year-old daughter Mikayla had several cavities.

One hole was so deep it reached the nerves inside the living pulp of her tooth.

"I was horrified and my first reaction was, what has caused this? Why her?"

Mikayla, now 5, is on the waiting list to go under general anaesthetic for two fillings.

The pulp of one tooth may need to be removed and a stainless steel crown fitted.

"We've got to wait six weeks to have the treatment done. In the meantime, she's in discomfort."

The Kumeu mother of four said she was in a better position than most to know about how to care for teeth but there had been no warnings of her daughter's tooth decay.

She brushed Mikayla's teeth twice a day and kept her away from sugary treats.

But as a baby, she often gave Mikayla a bottle of milk when she woke at night crying: "I knew in the back of my mind it wasn't good".

However, Mikayla was scared of going to the dentist from a young age, which made check-ups difficult.

Graham said parents had to be educated about how to care for their children's teeth, to prevent the pain of early decay.

SIMPLE IS BEST WHEN IT COMES TO CARING FOR CHILDREN'S TEETH

A healthy balanced diet doesn't need to be expensive, according to Mission Nutrition nutritionist Claire Turnbull.

Her tips include eating fruit and vegetables that are in season, using lentils, chickpeas and beans to bulk out meat dishes and drinking tapwater rather than juice or soft drinks.

She says that healthy eating can save time in the long run because "you will feel better, work better, concentrate better and be able to be more efficient".

Foods with a high sugar content are bad news for teeth, and children who snack often are most at risk.

Decay is caused when bacteria in the mouth comes into contact with sugar, turning it into lactic acid, which slowly breaks down the tooth's surface.

Specialist paediatric dentist Nina Vasan recommends healthy snacks with little or no sugar and sipping water after snacking to dilute lactic acid build-up.

Juice and soft drinks should be avoided but if drunk, should be consumed through a straw so the liquid doesn't touch the teeth, says Vasan.