Effect of school-based fluoride varnish programmes on approximal caries in adolescents from different caries risk areas

The aim was to evaluate, in a 3-year RCT study, school-based fluoride varnish programme on approximal caries incidence and approximal caries progression in 13- to 16-year-olds in high, medium and low caries risk areas on the Swedish west coast. Seven hundred and fifty-eight (89%) fulfilled the trial. Using a simple mobile unit, 2 dental nurses treated the adolescents with F varnish: ( 1) twice a year at 6-month intervals, ( 2) 3 times a year within 1 week, ( 3) 8 times per year during the semesters with 1-month intervals, and ( 4) no treatment ( control). Radiographic caries recording was performed blindly by one of the authors. Concerning total approximal caries incidence, control groups in all areas developed more caries than F varnish groups, with the largest difference in the high risk area: 3.05 +/- 3.37 new approximal caries lesions ( mean +/- SD) compared to 0.54 +/- 1.26 for group 3, 0.95 +/- 1.67 for group 1 and 1.40 +/- 1.89 for group 2 ( p < 0.001). More than 90% of the new approximal lesions in all the groups and in all areas consisted of new enamel lesions. Regarding progression of enamel lesions, there were only significant differences between groups 1 - 3 and group 4 in the high caries risk area. Prevented fraction for fluoride varnish treatment twice a year at 6-month intervals was 69% in high, 66% in medium and 20% in low risk areas. To conclude, school-based F varnish treatment every 6 months in 13- to 16-year- olds is excellent to prevent approximal caries in medium and high caries risk areas. Copyright (C) 2005 S. Karger AG, Basel.