Conclusion and review of the Michigan Xylitol Programme (1986-1995) for the prevention of dental caries.

The major results of the Michigan Xylitol Programme (1986-1995) are summarised. The Programme consisted of several clinical trials and laboratory investigations designed to study the usage of xylitol-containing saliva stimulants in the prevention of dental caries. The trials patients included young (initially 6 year olds) and adult or geriatric subjects who were given saliva stimulants (mostly chewing gum) for periods of two weeks to 56 months. A special rationale behind these studies was the need to further test the validity of the 'pentitol-hexitol theory' in the prevention of caries. This theory has maintained that pentitols (sugar alcohols with five hydroxyl groups, such as xylitol) may be cariologically more effective than hexitols (sugar alcohols with six hydroxyl groups, such as sorbitol). The accumulated clinical, sialochemical and microbiologic evidence suggests that xylitol, a natural carbohydrate sweetener of the pentitol type, is more effective in preventing dental caries than sorbitol, and cariologically safer than sorbitol, a natural carbohydrate of the hexitol type. Sorbitol was found to be significantly less cariogenic than sucrose. The Programme's results shed additional light on the cariologic and oral biologic effects of natural, dietary polyols, and suggest that the usage of xylitol chewing gum (and in some cases xylitol dragées) can be considered a valuable additional tool in caries prevention and in stabilisation of caries in all age groups.