A couple of pieces of medicated gum a day may keep the dentist away, at least for frail senior citizens.

Researchers studied 111 seniors living in 16 residential homes in England. They divided them into three groups. One group chewed gum with a combination of chlorhexidine acetate and xylitol (called ACHX in the study); another chewed xylitol gum (called X); and the third group chewed nothing. Those who got either of the gums chewed one piece after breakfast and another after dinner.

Both gums stimulated the flow of saliva, but test subjects who got the xylitol gum or no gum had higher levels in their mouths of three microorganisms that are most associated with tooth decay, lactobacilli and yeasts.

Both chewing gums reduced the amount of denture debris, sores around dentures and cracks at the corners of the mouth.