Effect Of Fluoride Varnish And Fluoride Foam On Caries Prevention In Orthodontic Treatment And On The Demineralization Of Enamel In Vitro

Objective: The purpose of the clinical experiment is to compare the effect of fluoride varnish and fluoride foam in preventing caries during one-year orthodontic treatment; in vitro the inhibitory effect of fluoride varnish and fluoride foam on demineralization of human emamel was compared .Methods: 172 orthodontic subjects aged 10-25 year-old were assigned into A-E five groups :A group received fluoride varnish application every 6 months ,B group received fluoride foam application every 6 months ,in C group application of fluoride varnish and fluoride foam take turns every 3 months ,D group received fluoride foam application every 3 months ,E group served as the control .The increased mean DFS of every group was compared one year latter.26 non-caries human emamel blocks were randomly divided in two groups .Of each sample ,one half was used as experiment ,the other was used as control .After fluoride varnish and fluoride foam application ,the enamel blocks faced artificial caries attack ,then the microhardness of enamel surface of all samples was detected and the enamel lesions of demineralization was observed by polarized light microscopy.Results: Compared with the increased mean DFS of the control(1.8571), application of fluoride varnish every 6 months(0.6176) in orthodontic subjects has statistically caries-reducing effect(p<0.05), the preventing effect is the same as application fluoride foam every 3 months(0.4737) and application fluoride varnish and fluoride foam taking turns every 3 months(0.3448) (p>0.05),application fluoride foam every 6 months(1.5556) has no significant caries-reducing effect(p>0.05). By comparing the decrease of the microhardness of enamel surface with corresponding control groups (69.936, 111.448), both fluoride varnish (37.764)and fluoride foam (69.692)are effective in inhibiting acid solubility and enhancing the microhamess of enamel(p<0.05) ,but the former was increased more than the latter(p<0.05).Conclusion: Both fluoride varnish and fluoride foam can inhibit acid solubility of enamel and prevent the forming of caries lesion in orthodontic treatment, but fluoride varnish has a better effect .If the frequency of fluoride foam application was increased , the caries prevention effect will be significant in orthodontic groups.