Effects of a fluoride-releasing fissure sealant on artificial enamel caries

This study examined the effect of a fluoride-releasing fissure sealant upon enamel demineralization in an artificial-caries system. Twenty extracted human molars were randomly assigned to two treatment groups consisting of (1) conventional fissure sealant and (2) fluoride-releasing sealant. Specimens were acid-etched, rinsed, dried, sealant applied, and photocured for 20 seconds. Teeth were thermocycled 500x between 5 degrees C and 55 degrees C using 1 minute dwell times. Acid-resistant varnish was placed on the specimens to within 1 mm of the sealant and the teeth were subjected to an artificial-caries challenge at pH 4.2 for 62 hours. Teeth were then sectioned and the thin-sections photographed using a polarizing-light microscope. Areas of the artificial-caries lesions and their depths were measured using a sonic-digitizing pad. Mean lesion depths (in arbitrary units from the digitizing pads) were 4.17 +/- 0.95 for Group 1 and 1.22 +/- 0.61 for Group 2. Mean areas were 17.26 +/- 7.32 for Group 1 and 3.12 +/- 2.59 for Group 2. Students' t-tests indicated statistically significant differences (P less than 0.001) between groups for both measures. This artificial-caries study indicates that a fluoride-releasing fissure sealant substantially reduces the amount of enamel demineralization adjacent to the material.