Those who can least afford it are missing out on dental care, says the Dental Association.

Photo: 123RF

Help for the low paid is available through Work and Income, but the association says this covers only emergency work and there's a case for increased government subsidies to help people get the care they need.

Couple Jarred and Mel Smith admit to having terrible teeth, which caused them pain and other problems.

"It does your head in, you can't think, I've got five children, I've been getting grumpy," said Jarred Smith.

Photo: RNZ / Conan Young

Mel Smith said it put her off going to get a job.

"Even just talking to people [you're] covering your mouth and [you get] bad breath."

Going through the hospital was their best option, she said.

"I mean, my teeth are buggered, I need all of my teeth pulled out and it's going to cost $4000 to $5000. Going to the hospital is probably going to cost $300 to $400 which is a lot cheaper."

But Jarred Smith said there was a long wait.

"It's up to four months for our teeth to come out. I was in agony for two months and I went there the other day and they pulled out two."

Dental Association president Bill O'Connor said the help offered by Work and Income was an ambulance at the bottom of the cliff.

He said not enough was being done to stop people like the Smiths from ending up with teeth so bad, they needed to have all of them removed.

"It's probably not enough for most of the people that use that service. It'll get them out of pain and get an immediate problem fixed, but it doesn't solve long term problems."

Mr O'Connor, who was also a dentist, said the argument could be made the government needed to extend free dental care beyond the age of 18, but it was complicated.

"I'm sure there's a case to be made for it to be subsidised for a longer period of time. I guess [you have to ask] where do you stop and how much is it going to cost. Kids leave ... the system at 18 and they should be dentally fit. So I don't know, where do you stop."

So just how expensive is it to visit the dentist?

In Christchurch, a filling at the Linwood Dental Centre in Christchurch cost $160, but across town it could have cost more, from $200 to $350 at one central city practice.

It was a similar story at two further dentists - up to twice as much as the filling at Linwood Dental - while a fourth charged just slightly more.

A root canal would set you back between $1000 to $1300.

Dentist Peter Payne, at the Linwood Dental Centre, said he charged less because that was all most of the people he saw could afford.

"Dentistry has to be sensitive to the patient's ability to pay but we can't charge so little that we can't buy the right products. If I buy an electric drill, I don't buy the most expensive one, I buy the mid-range."

Photo: RNZ / Conan Young

This dentist, who had been working in lower socio-economic Linwood for 40 years, said the two main reasons people did not visit him as much as they should were a fear of going to the dentist and the cost.

He said for those who could least afford it, help from Work and Income was available, but not always.

"We do a lot of quotes for Work and Income and they will provide money to people, it seems to be on a haphazard basis, some people can get all of the money, we might say $1500 for some cases and other people struggle to get $200 or $300."

When it comes to getting your teeth fixed, it really does pay to shop around.

A Consumer New Zealand survey across the country recently confirmed RNZ's experience in contacting dentists in Christchurch.

Chief executive Sue Chetwin said it found a huge variation in what they charged - from $80 to $500 - depending on whether a composite or amalgam filling was used.

"Most of the practices would give us an estimate, you know if you rang up and asked how much would a filling cost. Obviously those are quite broad numbers, but we found some dental practices refused to even give that sort of estimate and we thought that was poor because people should be able to shop around."

The price was also affected by location and the cheapest dental care was in Auckland.

"In Auckland for separate appointments for an exam and clean it was $226, in Wellington $284, in Christchurch $240."

The chances of any sort of help from the government towards the cost of dentistry currently look slim.

Asked for comment, Minister of Health David Clark replied in a statement that while he wanted dental care to become more accessible and affordable over time, there were no immediate plans to change the current entitlement age for free care beyond 18.