Long-term effect of xylitol chewing gum in the prevention of dental caries: a follow-up 5 years after termination of a prevention program.

About 65% of the original 258 children who participated in 1982-1984 in a caries prevention program involving the use of xylitol chewing gum were retrieved in 1989 for a follow-up study. Ninety-five subjects from the original xylitol (X) group and 70 subjects from the original control (no-gum, C) group were available. In 1984, when the children completed the program at the age of 13-14 years, the caries scores were significantly lower in children who had used xylitol gums daily, compared with the C group. In 1989, 5 years after the discontinuation of the gum program, the difference between the X and C groups had continued to increase in favor of the X group. These effects were explained by assuming that the X gum program had facilitated the establishment of a low-virulent bacterial flora on the surfaces of the teeth, and especially on those teeth that erupted during the trial proper. This type of results are possibly helpful when evaluating cost-benefit ratios of caries prevention.