The purpose of this study was to evaluate the difference in mineral loss of incipient enamel artificial carious lesions that were sealed with fluoride- or nonfluoride-containing resin sealant. Two artificial lesions (2x2 mm2 each) were creat-ed on buccal surface of 60 premolars by using Carbopol demineralizing solution. Lesions in the first group (30 teeth) was sealed with Delton® and Delton®Plus, the second group (30 teeth) was sealed with Helioseal® and Helioseal®F. All teeth were immersed in artificial saliva for 7 days and sectioned through the lesions. The cross-sectioned surfaces were polished and then subjected to Vickers hardness measurement at 20 mm from the resin-enamel interface, and every 10 mm inwards across the lesion to the underlying sound enamel. Mineral content was converted from hardness num-ber. Mean mineral loss was calculated and was compared between lesions sealed with fluoride- or nonfluoride-con-
taining sealants. Mean±SD of mineral loss for Delton, Delton Plus, Helioseal and Helioseal-F were 1423±441, 1287±421, 1223±284, and 1165±267 VPM·mm, respectively. Paired t-test showed that the mineral loss of incipient enamel carious lesions sealed with fluoride-containing sealants, Delton Plus and Helioseal-F, were not significantly dif-ferent from those of nonfluoride-containing sealants, Delton and Helioseal (P>0.05).