To date, effective caries prevention largely relies on the regular use of fluoride and oral hygiene. The potential efficacy of basing caries prevention on nutritional modifications has been suggested a long time ago. Subsequently, a great number of laboratory, animal and clinical investigations have convincingly demonstrated that partial substitution of sugar by noncariogenic sweeteners offers considerable benefits for dental health. This article reviews scientific information on sorbitol and xylitol, two caloric sugar substitutes that have been extensively studied with regard to their noncariogenic properties.