Death of dentures as patients grow own teeth

Published on Monday 3 August 2009 22:04

DENTISTS in the future could be able to make their patients grow new teeth by planting tooth "seeds" in their jaws.

Scientists have successfully grown replacement teeth in mice and say the technique could be developed for use in humans. The treatment would be much cheaper and more readily available than tooth implants.

Professor Takashi Tsuji and his team at the University of Tokyo grew a tooth "germ" in a laboratory and transplanted it into the jaw of a mouse.

The seed tissue contains all the cells and "instructions" necessary to grow and, when transplanted, grew into normal-looking teeth with all the usual structures, including enamel and blood vessels.

Using a fluorescent protein, the researchers tracked genes in the transplanted bud and found that all those normally active during tooth development were present during the growth of the bud.

The bioengineered tooth's hardness was comparable with natural teeth, and nerve fibres could grow throughout and respond to pain stimulation.

Technology already exists to grow organ tissue in a laboratory that can be transplanted into animals, but this is the first time a new three-dimensional organ has been grown in a living animal from just a few cells.

Professor Tsuji believes the technique could also be adapted to enable patients to regrow organs which are damaged.

He said: "This study demonstrates a technique that could lead to the development of bioengineered organ replacements, potentially providing a prelude to the ability to grow new, fully functional organs inside the body from stem cells or other germ cells."

The study, published in proceedings of the National Academy of Sciences, reported the teeth were "fully functioning" and had the correct structure, strength of mineralised tissues for chewing and response to pain.

Prof Tsuji said: "We propose this technology as a model for future organ-replacement therapies. This study represents a substantial advance and emphasises the potential for bioengineered organ replacement in future regenerative therapies."

John Drummond, a senior lecturer in restorative dentistry at the University of Dundee and president of the British Dental Association, said the successful implantation of a tooth bud could herald a new era in dentistry.

"This sort of development is probably the future," he said. "Something like this has a huge potential to replace teeth that have been lost."

He added: "I would guess we are at least a decade away from this being available to patients because so many clinical trials and tests have to be carried out. But it has the potential to be a lot less expensive than something that involves a titanium implant into the jaw.

"Potentially, the surgery involved in something like this could be a lot more straightforward. It could very well be something every dentist would be able to do."

SOLUTION WITH BITE: TITANIUM IMPLANTS

DENTAL implants are currently the best way to replace lost or missing teeth.

The treatment involves a titanium screw being driven into the jawbone and capped with a porcelain crown.

In time, the titanium becomes fused with the bone.

Implants, which cost at least 1,000 per tooth and can only be carried out by dentists who have undergone postgraduate training, have been available in this country since the 1980s. An estimated 7 million implants have been placed.

The procedure is carried out under general anaesthetic. Where the jawbone is not strong enough, additional bone may be grafted from the hip.

In 1970, a Brazilian dental scientist showed that the Mayan civilisation carried out dental implants 1,350 years ago, after studying the remains of a woman who had tooth-like pieces of shell screwed into her jaw.