An overview of studies about xylitol and dental caries suggests potential clinical dental applications for xylitol. Xylitol is a naturally occurring, low-calorie sugar substitute with anticariogenic properties. Data from recent studies indicate that xylitol can reduce the occurrence of dental caries in young children, schoolchildren, and mothers, and in children via their mothers. Xylitol, a sugar alcohol, is derived mainly from birch and other hardwood trees. Short-term consumption of xylitol is associated with decreased Streptococcus mutans levels in saliva and plaque. Aside from decreasing dental caries, xylitol may also decrease the transmission of S. mutans from mothers to children. Commercial xylitol-containing products may be used to help control rampant decay in primary dentition. Studies of schoolchildren in Belize and Estonia, along with data from the University of Washington, indicate that xylitol gum, candy, ice pops, cookies, puddings, etc., in combination with other dental therapies, are associated with the arrest of carious lesions. A prospective trial in Finland has demonstrated that children of mothers treated with xylitol had lower levels of S. mutans than children of mothers treated with chlorhexidine or fluoride varnish. Food products containing xylitol are available commercially and through specialized manufacturers, and have the potential to be widely accessible to consumers.