Does sugar-free gum with xylitol prevent cavities?

Cleans and protects teeth. Helps prevent cavities. So say popular brands of sugar-free gum. But do their claims stand up to scrutiny? Many brands contain xylitol, a natural sweetener known to fight cavity-causing bacteria. But it's not clear that xylitol has much impact. Some research suggests that while sugar-free gum does prevent cavities, xylitol per se is not responsible. One new study, published this month in the Journal of the American Dental Association, tracked 691 adults for three years. The subjects were randomly assigned to groups consuming xylitol lozenges five times a day or a placebo. Those who received the xylitol had no statistically significant reduction in cavities. NEW YORK TIMES