Comparison of the use of a child and an adult dentifrice by a sample of preschool children.

The purpose of this study was to compare the use of a child dentifrice (CD) and an adult dentifrice (AD) by a convenience sample of preschool-aged children. Fifty participants, ages 31 to 60 months, were recruited from a dental school clinic and an area day care center. All were healthy, free of developmental delays, and capable of applying dentifrice to a toothbrush. The study employed a crossover design in which the children each brushed their teeth twice, once with each type of dentifrice. The order of dentifrice use was assigned randomly, and the two brushings were separated by at least 1 week. The following were recorded: 1) the amount of dentifrice applied, 2) the time spent brushing, and 3) whether the child expectorated and/or rinsed after brushing. The mean weight of CD the children used (0.689 g, 0.43 SD) was significantly greater than that of AD (0.509 g, 0.41 SD, P = 0.02, Wilcoxon's signed rank test). The mean time spent brushing with CD (83.56 sec, 85.4 SD) was significantly greater than for AD (57.48 sec, 39.0 SD, P = 0.01). A "risk factor" (dentifrice weight x usage time) was derived to estimate the relative fluoride exposure of each child. The mean risk factor for CD (58.54, 64.8 SD) was significantly greater than that for AD (27.43, 25.0 SD, P < 0.001). Most children did not expectorate or rinse after brushing. Most parents selected drawings on a questionnaire that indicated that their child routinely used 0.25-0.5 g of dentifrice per brushing, which underestimated the amount they used in the study. The results of this study indicated that young children may be exposed to more fluoride for a longer period of time with CD.