Methods: In this two-year, prospective, cluster-randomized, concurrent controlled, open trial of the dental health program compared to no such program, 30 communities were allocated at random to intervention and control groups. All residents aged 18-47 months were invited to participate. Twice per year in the 15 intervention communities, fluoride varnish was applied to children's teeth, water consumption and daily tooth cleaning with toothpaste was advocated, dental health was promoted in community settings, and primary health care workers were trained in preventive dental care. Data from dental examinations at baseline and after two years were used to compute net dental caries increment per child (d3mfs). A multi-level statistical model compared d3mfs between intervention and control groups with adjustment for the clustered randomization design; four other models used additional variables for adjustment.
Results: At baseline, 666 children were examined; 543 of them (82%) were re-examined two years later. In both groups, 90% of children developed one or more new carious lesions. The adjusted d3mfs increment was significantly lower in the intervention group compared to the control group by an average of 3.0 surfaces per child (95%CI = 1.2, 4.9), a prevented fraction of 31%. Presence of fluoride in drinking water was also associated with significantly lower caries increment. Adjustment for additional variables yielded caries reductions due to the intervention that ranged from 2.3 - 3.5 surfaces per child. In preference to the conventional measure of number needed to treat, we estimated that 33 children would need to receive the intervention to prevent 100 cavities.
Conclusions: This community intervention, which included fluoride varnish, had significant oral health benefits for children in these high risk communities.