Effect of a fluoride varnish on demineralization adjacent to orthodontic brackets

Home fluoride regimens have long been used to reduce the amount of deminera lization adjacent to orthodontic appliances. In the absence of patient comp liance, another method of applying the fluoride must be used. The purpose o f this study was to evaluate, in vitro, the ability of a fluoride varnish, Duraflor, to directly inhibit demineralization of enamel surrounding orthod ontic brackets. Brackets were bonded to 36 extracted human canines and prem olars with a traditional composite resin and randomly assigned to three equ al groups of twelve. Group 1 served as the control with no topical applicat ion after bonding. Group 2 was treated with a single application of a nonfl uoridated placebo varnish. Group 3 was treated with a single application of Duraflor. All groups were cycled in an artificial caries challenge for 1 h our two times daily for 37 days and were brushed with a medium bristled too thbrush to simulate mechanical wear of the varnish. Demineralization of ena mel was evaluated in longitudinal buccolingual tooth sections using polariz ed light microscopy. Both average depth and area of demineralization were m easured with a sonic digitizer. ANOVA (P less than or equal to.0001) and Du ncan's test (P less than or equal to.05) indicated significant differences in depth and area of demineralized enamel. Those teeth treated with Duraflo r exhibited 50% less demineralization than the control teeth and an even gr eater difference when compared to the placebo group. Fluoride varnishes sho uld be considered for use as a preventive adjunct to reduce enamel deminera lization adjacent to orthodontic brackets, particularly in patients who exh ibit poor compliance with oral hygiene and home fluoride use.