Anticaries efficacy of a sodium monofluorophosphate dentifrice containing xylitol in a dicalcium phosphate dihydrate base. A 30-month caries clinical study in Costa Rica.

PURPOSE To compare the long-term caries increment associated with the use of two dentifrices: (1) a test dentifrice containing 0.836% sodium monofluorophosphate (1100 ppm F) in a dicalcium phosphate dihydrate base plus 10% xylitol; and (2) a positive control dentifrice containing 0.836% sodium monofluorophosphate (1100 ppm F) in a dicalcium phosphate dihydrate base. MATERIALS AND METHODS Three thousand three hundred ninety four (3,394) school children aged 7-12 years were selected to participate in this double blind clinical caries study at 28 public schools in the central plateau of Costa Rica. Children accepted for participation were stratified into two balanced groups within the participating schools on the basis of age and sex, and assigned to one of the two dentifrices. The study was conducted in harmony with the guidelines for caries clinical studies published in 1988 by the Council on Dental Therapeutics of the American Dental Association, and employed clinical diagnostic criteria provided in 1991 guidelines published by the National Institute of Dental Research (NIH/NIDR). Dental radiographs were not employed. RESULTS Of those subjects who met the initial inclusion/exclusion criteria for this study, 2,539 were available for the 30-month exam. DFS increments over the 30-month period of this clinical study were 1.30 for the test dentifrice containing 10% xylitol, and 1.51 for the positive control dentifrice without xylitol; for DFT, the corresponding increments were 0.69 for the test dentifrice containing 10% xylitol, and 0.81 for that which did not contain xylitol. For both DFS and DFT, the increments associated with the test dentifrice containing 10% xylitol were statistically significantly lower than those associated with the positive dentifrice without xylitol (P < 0.05), with the observed reductions in caries increment exceeding 10% in for both parameters.