Scientists crack tooth decay

Sep 7 2004

About half of today’s children have tooth decay, so a new solution that blocks the action of bacteria which attack teeth could bring significant benefits, according to scientists speaking Monday at the Society for General Microbiology’s 155th Meeting at Trinity College Dublin.

Researchers from the Department of Oral Immunology at King's College London have discovered how the bacteria which attack teeth, Streptococcus mutans, attach themselves to the enamel surface. Once stuck on, the bacteria convert sugar from our food into acid which then attacks the tooth surface.

“The bacteria use a special protein to recognise teeth, and it fits snugly into their surface like a key fitting into a lock. We have identified the small part of the protein which acts like the key,” says Professor Charles Kelly of King's College London. “We made identical copies of the small part of the protein, called a peptide, and dripped it onto the teeth of volunteers to see whether it would block up all the possible keyholes, stopping bacteria from attaching to the teeth themselves.”

After three weeks of treatment with the peptide solution the volunteers were monitored for the next three months to see whether any of them became infected with tooth decay bacteria. None of the treated volunteers suffered any tooth decay infection, while other volunteers who received no treatment, or a solution containing a similar but useless peptide, did become infected with Streptococcus mutans.

This study has provided important evidence that a simple peptide could provide a protective solution to tooth decay, by preventing the attacking bacteria from attaching to tooth enamel. Eventually the scientists hope other types of infection might be blocked using the same technique.