Chemists are testing a material that could stimulate teeth to repair their own small cavities.

Joe Antonucci, a polymer expert at the US national institute of standards and technology, told the American Chemical Society meeting in Chicago yesterday that a sealant containing amorphous calcium phosphate (ACP) had triggered new mineral growth in cows' teeth in a laboratory experiment.

ACP will not end visits to the dentist. The material cannot reverse any advanced decay. But it could stop small cavities from getting bigger.

The first use for the substance, however, is likely to be as an orthodontic glue, Dr Antonucci said.

"One of the problems with using orthodontics in children's mouths is that where they are attached to teeth by braces, there tends to be demineralisation around that tooth. Using this kind of adhesive that has the ability to remineralise the tooth, or at least prevent demineralisation, we believe can be a distinct advantage."

Children with braces on their teeth have a problem trying to keep them clean. The clamps that hold the braces in place also trap food particles and plaque, triggering the loss of minerals and the beginning of decay. Dr Antonucci and his team see their new polymer as a way of reversing the decay.

They also see it as a liner or base for dental fillings, protecting against secondary cavities that form under or around conventional fillings.

Dental health is a problem in all societies. Two years ago one research team reported that dental caries, inflamed gums and a whole mouthful of troubles seemed to increase as economic stress set in.

Dental researchers are working on an arsenal of new treatments for troubled teeth. British genetic engineers reported last year that they were trying to develop apples and strawberries that would deliver a protein to stop decay bacteria from colonising tooth enamel.

But Dr Antonucci's polymer could do more than just protect teeth, he told the conference. It could play a part in bone repair. If ACP can release calcium and phosphate to make the hydroxyapatite, the substance of teeth, a biodegradable mixture injected carefully could also one day help plastic surgeons trying to reconstruct bone after injury.