Caries preventive effects of xylitol-based candies and lozenges: a systematic review.

A systematic review of published data was conducted with the aim of assessing the caries preventive effect of consuming xylitol-based candies and lozenges. Electronic and hand searches were performed to find clinical trials concerning the consumption of products containing xylitol, published up to November 2009. The studies must have had the following characteristics: (a) a comparison of caries progression in subjects who either did or did not consume candies or lozenges containing xylitol during a minimum follow-up period of 1 year; and (b) a concurrent comparison of the percentage of caries progression according to the World Health Organization criteria. The caries preventive effect of xylitol was assessed by calculating the prevented fraction. The initial search identified 127 references. Six studies met the initial eligibility criteria, but three were excluded after thorough analysis. Two more articles were selected after hand searching, but they were excluded due to the presence of chewing gum in the experimental group. Of the three selected studies, two found a lower caries increment in the treatment groups. Although the findings of the analyzed studies suggest that the use of xylitol-based candies and lozenges could favor a reduction in caries increment, in general, their consumption did not seem to be effective on the proximal surfaces. Nevertheless, these findings are not supported by strong evidence. This research demonstrates the need for well-designed randomized clinical studies with adequate control groups and high compliance by the subjects.