Evaluation of the comparative effectiveness of fluoride mouthrinsing, fluoride tablets, and both procedures in combination: interim findings after two years.

Children in kindergarten and first grade (mostly 5 and 6 year olds) in a nonfluoridated city were assigned randomly in each of 20 schools to: rinse weekly with a 0.2% NaF solution, ingest daily a 2.2 mg NaF tablet, or carry out both procedures, for 8 years. At baseline (1981), 1640 participants were examined clinically 3 National Institute of Dental Research (NIDR) investigators who used the dmfs (for primary molars only) and DMFS indexes. After 2 years (1983), 1154 subjects were available for reexamination. For primary teeth, subjects in the combination treatment group had a mean increment of 1.67 dmfs, 18.9% lower than the mean scores of 2.06 dmfs for children in the tablet group and 33.2% lower than the 2.50 dmfs for those in the rinse group. Results in primary teeth by type of surface also showed consistently lower scores in the combination group than in the other treatment groups. The differences in overall caries increments among the 3 groups approached statistical significance (P = 0.06). For permanent teeth, mean increments (essentially in pits and fissure surfaces of first molars) for each group were small (< 1 DMFS/ child) and similar. The findings of this study suggest that primary molars may receive enhanced anticaries benefits from a combined fluoride program in school when exposure begins in kindergarten and first grade. Also, the findings in primary molars portend more substantial results in permanent teeth as the evaluation continues. Increasing evidence indicates that various combinations of fluoride agents produce additive anticariogenic effects (Horowitz 1980; Federation Dentaire International 1984). Self-administered fluoride procedures that may exert their cariostatic effects by different mechanisms of action are likely to achieve maximum caries-preventive benefits most efficiently. The National Institute of Dental Research (NIDR) has published a series of reports of a long-term dental health program in which a combination of fluoride procedures is used.’ In that program, school children 1 Horowitz et al. 1977, 1979; Horowitz 1980, 1984. in Nelson County, Virginia, an area with negligible concentrations of fluoride in its drinking water, ingest a dietary fluoride supplement daily and rinse with a fluoride solution weekly. In addition, fluoride dentifrice is provided for ad libitum use at home. This combination of self-administered methods was selected to provide permanent teeth with systemic exposure to fluoride before eruption (from dietary supplements) and topical exposure to teeth after eruption (from rinse, dentifrice, and dietary supplement). Final results after 11 years showed that the prevalence of dental caries among participants was reduced by about 65% compared with caries scores of school children before the program began (Horowitz et al. 1986). Striking results were obtained in approximal surfaces of teeth--a 90% lower prevalence of dental caries (Horowitz et al. 1986). The anticaries effects of the combined fluoride regimen observed in Nelson County are greater than those usually reported for any of the individual components, suggesting an additive effect. 2 However, because all participating children received the entire regimen, claims of additive effects cannot be made; not all the preventive regimens used may have been necessary to produce the observed benefit. The present study was undertaken by NIDR to determine whether the combined use of school-based programs of fluoride rinsing and fluoride tablets produce additive effects. Because almost 95% of all dentifrice now sold in the United States contains fluoride (Heifetz and Horowitz 1986), the present study likely represents an evaluation of the combined fluoride therapies superimposed upon a background of home use Driscol11974; ADA Council on Dental Therapeutics 1975; Heifetz and Horowitz 1986. PEDIATRIC DENTISTRY: June 1987/Vol. 9 No. 2 121 of fluoride dentifrice, a situation akin to the Nelson County study.