The effect of sugar alcohols on plaque and saliva level of Streptococcus mutans.

The usage of sucrose substitutes such as polyols in snack-type foods is a logical and practical means of reducing caries incidence without perturbing normal dietary eating patterns. S. mutans and L. casei can ferment mannitol and sorbitol, but are inactive towards xylitol. This ability of these cariogenic organisms to ferment the hexitols does not seem to be of concern when gums containing them are used at the normal rate. However, when hexitol gum usage is excessive, the S. mutans levels may increase. In contrast to the hexitols, excessive usage of gums sweetened with xylitol caused a significant decrease in the levels and proportions of S. mutans in saliva and plaque. While this effect on S. mutans may be an indirect one, this finding provides added evidence for the superiority of xylitol as a sucrose substitute in dentistry.