LONDON (Reuters) - Chewing sugar-free chewing gum after meals prevents tooth decay and caries by 28 per cent, scientists at the University of London said on Thursday.

Chewing gum helps produce more saliva, which in turn neutralizes the acid that forms when we eat. These acids usually stick to the mouth and teeth for 20 minutes after a meal.

It is recommended to chew sugar-free gum because sugar causes dental caries that turn into plaque when they interact with bacteria in the mouth.

The researchers also say that artificial sweeteners in sugar-free gum such as xylitol and sorbitol may help keep mouths sterile.

Both are believed to increase the production of proteins in the immune system that resist germs that lead to tooth rot.