OBJECTIVETo evaluate the effect of bi-annual professional application of 1.23% fluoride foam on caries reduction in the primary dentition over a two-year period.

METHODSIn a double-blind, cluster-randomised, placebo-controlled trial, 392 children aged 3 - 4 years from 15 classes were randomly assigned to two groups on a school class basis. The experimental group (8 classes) received a bi-annual fluoride foam application, and the placebo control group (7 classes) received the placebo. The analysis of caries increment was based on the class as the unit of analysis. The independent-samples t tests were performed to compare the differences in caries indices at baseline and caries increments between the two groups.

RESULTSThe mean caries increment in foam group was 3.8 dmfs while it was 5.0 dmfs in the placebo control group, resulting in 24.2% caries reduction (P < 0.05). The experimental group had a 37.6% caries reduction on approximal surfaces compared with the placebo control group (P < 0.01). Although the mean dmfs increment of bucco-lingual surfaces was lower in the experimental group than that in the control group, it was not statistically significant (P > 0.05). No significant difference in the mean caries increment was observed on occlusal surfaces between the two groups (P > 0.05).

CONCLUSIONSBi-annual professional application of fluoride foam was effective in reducing the increment of dental caries in the primary teeth.