KIDS tooth decay is on the rise - and drinking the wrong kind of water is to blame.

While tap water is treated with fluoride, which prevents decay, the trend for drinking bottled water has seen the number of children with problem teeth by age six jump to 49 per cent.

The situation has become so bad that tooth decay in children is now at its highest level since fluoridisation was introduced in the 1960s and 1970s, and many youngsters are needing hospital treatment to remove damaged milk teeth.

Sugary drinks, too many snacks and irregular or poor brushing are all contributing factors, but the Australian Dental Association said that exclusively giving kids bottled water or water that has had the fluoride filtered out is only making matters worse.

ADA chairman of oral health Dr Peter Alldritt said: "Children are being admitted to hospital every day to have general anaesthetic to have baby teeth removed.

"Bottled water is not 100 per cent to blame. It is also sweetened drinks, lollies and cakes and brushing once rather than twice a day."

Pediatric dental surgeon Dr Philippa Sawyer said a decade ago 60 per cent of five-year-olds had healthy, decay-free teeth.

"Using bottled water is one of the factors,'' she said. ``If you drink a bottle of water when you are at the shops, that's not a problem.

``If you do that continuously every day and the child is always drinking bottled water, that's going to be a problem."

Before drinking water began to be treated it was not unusual for children entering their teens to have a dozen decayed teeth, according to Adelaide University dentistry professor Kaye Roberts-Thomson.

"Before there was fluoride children were having an average of seven teeth effected, now it is about one," Prof Roberts-Thomson said. "Baby teeth in particular are being effected."

But she added that sugary drinks were responsible for more tooth decay than bottled water.

"It's better to drink bottled water than soft drinks and fruit juice, but the best thing to drink is tap water," Prof Roberts-Thomson said.

Alex Bowen, 43, said she always ensured her two sons, Henry, 4, George, 2, drank tap water.

"Luckily they've been really good," Ms Bowen, from Queens Park, in Sydney's east, said. "We've always tried to avoid giving them too many sweet things.

"At Daycare they had a dentist come in and talk to them about how to look after their teeth. They were taught to drink lots of water."

The anti-fluoridation lobby, which claims the additive is toxic, had mandatory fluoridation overturned in Queensland last year and councils there are gradually removing it.

But Prof Roberts-Thomson said was "absolutely no evidence" that it was harmful to health.

Dr Alldritt said most domestic water filters did not remove fluoride from tap water but reverse osmosis filters did.

Large bottles of spring water and small bottled water products usually had no fluoride content, he said. The ADA wants legislation making it compulsory for the fluoride content of bottled water to be clearly labelled.

When Giulia Mazzocca was six her doctor discovered decay in four teeth and told her mother Lorella she would need hospital treatment to remove one tooth and put crowns on the other three.

Ms Mazzocca said she chose to have her treated under general anaesthetic rather than being conscious in the dental chair.

"Had she had it done in the chair I think she would have probably done one (procedure) and not gone back for a long, long time," Ms Mazzocca said.

Bottled water was never part of Giulia's diet, but sweets and juices were.

Since the operation three years ago Ms Mazzocca has not cut out sweets for her daughter but has stepped up the amount of water from the tap, filtered with a jug that does not remove fluoride.

"It's really not something you stop in children,'' she said. ``You have to be wary of it and careful, but it is not to excess."

Ms Mazzocca said she would prefer it if there were no fluoride in tap water: "It is just having more chemicals going through your body."

media_camera Brothers, George (2) and Henry Read (4). Picture: Bradley Hunter

FIGHTING DECAY

- Children must brush their teeth no matter how young they are

- Try to avoid sticky foods as bacteria tends to cling to them a lot more and stick to the teeth

- If your child likes sugary or acidic drinks, like lemon or orange juice, get them to drink through a straw

- Chewing sugar-free gum after a meal can help avoid food getting caught in teeth

- Children should floss once or twice a week, or do it for them

- Try to drink tap water with fluoride