LONDON, Oct 21: A new toothpaste made from crab’s shell could reduce trips to the dentist by fighting infection in the mouth. The paste, which could be on sale in a year, contains tiny polymer particles each enclosing a speck of bacteria-killing agent.

Because they are sticky, the particles lodge in areas of the teeth and gums vulnerable to infection and are not washed away by saliva. As they react with water, each particle breaks down over time to release its load of triclosan — a widely used antimicrobial chemical.

Dr John Smart, who developed the toothpaste together with PhD student Sandra Kockisch at the University of Portsmouth, said: “The idea was to find some way to keep the therapeutic agent in the oral cavity for longer. People are not particularly keen on gels, and mouthwashes don’t stay in the mouth for very long.

“We have incorporated these particles into a glycerol base, which is the basic material of toothpaste. They get lodged in the cavities and gaps where the bacteria which cause tooth decay and gum disease grow. As water gets in, the drug slowly leaks out. On a daily basis your teeth and gums are protected by a sea of antimicrobial agent.”

The team looked at four polymers from which to produce the sticky particles. The best performer was chitosan — derived from chitin, the main component of crab and beetle shells.—dpa