Abstract: Objective To compare the preventive effect of fluoride varnish and fluoride foam on caries increment in deciduous teeth over a twoyear period and to provide theoretical basis for the caries prevention in the primary dentition in China. Method 220 children at 3~4 years old from two kindergartens were chosen with cluster sampling method and were randomly divided into two groups, fluoride foam group and fluoride varnish group. They received topical fluoride application four times over a 2year period of time. Oral examination was carried out every year. All the data were collected and the caries incidence, the mean increments of dmft (decayed, missing and filled teeth) and dmfs (decayed, missing and filled surfaces) of the two groups were compared. Results The mean increments of dmfs of the foam group after one and two years’ intervention were 2.58±4.36 and 3.85±5.15; and those of the varnish group were 0.95±2.28 and 1.94±3.32. The differences between the two groups were statistically significant(P＜0.01). Conclusion Fluoride varnish is more effective than fluoride foam in preventing caries of primary teeth.

Key words: fluoride varnish, fluoride foam, caries prevention, primary teeth