The effectiveness of xylitol in a school-based cluster-randomized clinical trial

The purpose of this double-blind, cluster-randomized clinical trial was to examine the effects of xylitol gummy bear snacks on dental caries progression in primary and permanent teeth of inner-city school children.

A total of 562 children aged 5-6 years were recruited from five elementary schools in East Cleveland, Ohio. Children were randomized by classroom to receive xylitol (7.8 g/day) or placebo (inulin fiber 20 g/day) gummy bears. Gummy bears were given three times per day for the 9-month kindergarten year within a supervised school environment. Children in both groups also received oral health education, toothbrush and fluoridated toothpaste, topical fluoride varnish treatment and dental sealants. The numbers of new decayed, missing, and filled surfaces for primary teeth (dmfs) and permanent teeth (DMFS) from baseline to the middle of 2nd grade (exit exam) were compared between the treatment (xylitol/placebo) groups using an optimally-weighted permutation test for cluster-randomized data.

The mean new d(3-6)mfs at the exit exam was 5.0 ± 7.6 and 4.0 ± 6.5 for the xylitol and placebo group, respectively. Similarly, the mean new D(3-6)MFS was 0.38 ± 0.88 and 0.48 ± 1.39 for the xylitol and placebo group, respectively. The adjusted mean difference between the two groups was not statistically significant: new d(3-6)mfs: mean 0.4, 95% CI -0.25, 0.8), and new D(3-6)MFS: mean 0.16, 95% CI -0.16, 0.43.

Xylitol consumption did not have additional benefit beyond other preventive measures. Caries progression in the permanent teeth of both groups was minimal, suggesting that other simultaneous prevention modalities may have masked the possible beneficial effects of xylitol in this trial.