Chemicals in red wine can help prevent and treat gum disease, a study says.
Past studies suggest red wine could cut cancer and heart disease risk
Canadian scientists believe the polyphenols can block production of free radical molecules, high levels of which can damage gum tissue.
The research, by Quebec's Universite Laval, was presented to the American Association for Dental Research.
However, dentists warn there are other risks associated with drinking wine, and people should not think it was good for their teeth.
The Canadian study suggests polyphenols stop free radical production by subtly changing the make-up of proteins within the cells that control their release.
Periodontitis destroys gum tissue and is a leading cause of teeth loss, affecting millions worldwide.
It is thought to be important to keep free radicals at low levels to maintain healthy gums, otherwise they can inflict damage on the tissue.
The bacteria that cause gum disease are thought to do so by stimulating immune cells to increase their free radical production.
Previous studies have suggested that the polyphenols in red wine may help to cut inflammation, and possibly the risk of both cancer and heart disease.
UK experts said polyphenols might prevent the inflammation getting worse - but were doubtful about their ability to block inflammation completely.
Professor Liz Kay, scientific adviser to the British Dental Association, said: "This wouldn't appear to show that red wine actually prevents periodontal disease.
"The sure way of doing so is to keep your mouth perfectly clean. That's achieved by brushing twice a day with fluoride toothpaste."
Leigh Greenwood, of the British Dental Health Foundation, said people should not think that drinking red wine was good for their teeth.
"It is important to remember that the acidic content of red wine could cause other problems, such as dental erosion.
"The best way to guard against problems such as gum disease is to adopt a good oral healthcare routine including twice daily brushing with fluoride toothpaste, daily flossing and limiting sugary food and drink to mealtimes."