Inhibition of enamel demineralization by a bioerodible fluoridated resin

PURPOSE: To investigate the efficacy of a bioerodible fluoridated resin on inhibition of enamel demineralization. METHODS: Eighteen extracted permanent molars were sectioned mesiodistally to obtain 36 caries-free enamel surfaces. Each sample was prepared by painting an acid-protective varnish, excluding a 2 x 8 mm window on either the buccal or lingual surface. The windows of exposed enamel were randomly divided into three separate groups (n = 12). Group 1 received an application of a 5% (by weight) sodium fluoride varnish. Group 2 had an experimental 5% sodium fluoride bioerodible resin applied to the window. Group 3 was left untreated and acted as a control. The samples were then exposed to an artificial caries challenge for 17 days, until a visible white spot lesion had been created on the control group. The samples were brushed for 1 minute daily. Following the acid challenge, the teeth were sectioned longitudinally to obtain 100 microm sections. Sections were then photographed under polarized light. Quantitatively the areas of the lesions were measured by utilizing a computerized imaging system. Finally, a comparison was made between mean lesion sizes of the sample groups in order to determine their respective efficacy of enamel demineralization inhibition. RESULTS: The mean areas (microm)2 of the artificial lesions (+/- SD) were: bioerodible fluoridated resin 3,785 +/- 1,794; fluoride varnish 7,362 +/- 2,853, and control 11,398 +/- 4,238. ANOVA was performed and identified a significant variance (P < 0.001). Tukey's multiple comparison test demonstrated that bioerodible fluoridated resin had significantly less enamel demineralization than the fluoride varnish and control groups (P < 0.05). The fluoride varnish group demonstrated significantly less enamel demineralization than the control group (P < 0.05).