You might not know his name, but Brisbane dentist Malcolm Campbell is a hero to hundreds of children in East Timor.

Once a year, with the help of other volunteers, he loads up a truck with a mobile dental clinic and travels through the troubled country delivering dental treatment to orphaned and impoverished children.

He's just returned from his fifth trip to the region since 2013, where two dental teams, including oral surgeons, two dentists and volunteer dental assistants, treated hundreds of children in Timor.

Dr Campbell said the state of the children's teeth was "absolutely shocking".

"There's one little boy who just broke my heart," he said.

The increasing popularity of processed foods is contributing to poor dental health in the country. ( Supplied: Malcolm Campbell )

"I don't even know his name but he was suffering and he just represented for me the heartbreak of the situation facing children in Timor.

"He was just a little boy with all these rotten teeth and we just decided we needed to do something to help him."

The World Health Organisation says that 12-year-old children should have no more than three decayed, missing, or filled teeth.

Dr Campbell said they were treating children with as many as 20 decayed teeth.

"I started my career as a [primary] school dentist, and I've never seen anything as bad as I've seen in Timor," he said.

There are only 10 dentists in East Timor — that means there's only one dentist to every 120,000 people.

By comparison, Australia is relatively spoilt with 57 dentists for every 100,000 people.

School dental program in the works

Access to health services is a major issue in Timor, with about 70 per cent of the population living in far-flung villages isolated by mountains and poor roads.

Dr Campbell spent a great deal of his own time raising $15,000 to buy portable dental equipment, to begin the first treatments at Dili's Samaria Children's Home, one of 40 orphanages in the country.

The homes provide shelter and care for young orphaned children or those put in care by their parents, simply unable to look after them any longer.

Dr Campbell had first visited the orphanage in 2013 as part of a church group and came home shocked and overwhelmed by what he saw, but determined to go back.

"We've been back every year since 2015 and expanded the project each time," Dr Campbell said.

"All of the volunteers donate their own time and money to get there and pay their own accommodation, so we really only fundraise to cover the cost of the equipment and materials," he said.

Volunteers pay for their own accommodation on the annual trips. ( Supplied: Malcolm Campbell )

The project has grown to also support a school in Dili, and people living in the remote community of Lospalos, a seven hour drive east of Dili.

Dr Campbell hopes at some point it will become locally operated.

"Through the Australian Embassy, we're dealing with the Ministry of Health in East Timor, trying to see how we can help them develop a school dental program," he said.

"We hope to work with Griffith University to get a program happening — so my aim would be to help empower them to develop some dental program of their own in Timor."

2019 trip already in the pipeline

Dr Campbell said it would include an element of education to teach Timorese children about dental hygiene.

"As the country is becoming more affluent, the influx of processed foods is increasing, so these kids are just eating rubbish," he said.

The project has grown to also support Marcelo 2 school in Dili. ( Supplied: Malcolm Campbell )

"I've got pictures of the school tuckshop and it's just tables full of sugary sweets and biscuits, so the decay rate is just terrible."

Dr Campbell is already planning the 2019 trip.

"I get a tremendous lift out of it — I've had a very blessed life and it's just paying it back," he said.

"I've got a lot to give and it's just something that I really enjoy but I also love seeing how it affects the other volunteers that come along and how it lifts them too and what they get out of it."