Effectiveness of Fluoride Varnish Application in Preschoolers: One-year Follow-up

Objective: to assess whether the application of fluoride varnish in preschool children at six-month intervals decreases the number of children with dentin caries and the incidence of caries lesions in the primary dentition, after one year. Possible side effects and intervention acceptability were also investigated. Methods: a randomized, examiner and patient-blind, placebo-controlled, parallel-group design, clinical trial, comprising 12 to 48 month-children, 100 in the test group (Duraphat,Colgate, fluoride varnish) and 100 in the control group (placebo varnish). Two trained pediatric dentists (Kappa=0.85) performed the clinical exams at baseline and every six months. Dental caries was recorded at the D1 (non-cavitated enamel lesion), D2 (cavitated enamel lesion) and D3 (dentin lesion) levels using the International Caries Diagnosis and Assessment System (ICDAS). Side effects and any complaints were assessed through semi-structured telephone interviews with the children's caregivers up to 2 weeks after the first varnish application. Results: 71 and 77 children of the test and the control groups were analyzed, respectively, and 13(18.3%) children in the test group and 20(26.0%) children in the control group presented new dentinal caries lesions (Chi-square test, p= 0.34). The mean caries increment differences between the control and the test groups were -0.3 (CI95%:-1.5;0.9) at the D1 level, -0.3(CI95%:-1.3;0.7) at the D2 level and -0.4(CI95%:-1.4;0.6) at the D3 level. One child reported a burning sensation in the mouth following application of the placebo varnish and the parent of one child felt upset about the yellowish discoloration of the child's teeth after the fluoride varnish application. Conclusion: six-monthly application of fluoride varnish in preschool children is safe and well-accepted, and may contribute to the control of caries initiation and progression. However, a longer follow-up period is necessary before conclusive evidence can be drawn regarding the effectiveness of this intervention.