Enamel demineralizing can occur due to various conditions, while white spot can be formed as an early tooth decay lesion. If these are neglected, weakened tooth due to enamel demineralizing can become chipped or it can progress into tooth decay. The most commonly used remineralization material is fluoride varnish. This study investigated remineralization and the physical changes of the tooth surface with erosion by using three different types of fluoride varnish. The specimen was prepared by using the anterior tooth of cattle, and early decay lesion was produced by using artificial demineralizing solution. Fluoride varnish was applied to each demineralized surface by using GC, ivoclar, and 3 M products according to the instruction of the manufacturer. Meanwhile, the remineralization degree of the surface after application was identified by using Quantitative Light-induced Fluorescence Detection (QLF-D). In addition, surface roughness before and after application was measured and recorded as Ra values. The surface roughness showed the most decreased value in the 3 M product, while the QLF-D of the early decaying lesion showed remineralization effect in all three products. The 3 M product has the most decreased ΔFmax value. This study demonstrated changes in tooth surface roughness after fluoride varnish application and remineralizing effect of the most commonly used products. Among the three products, 3 M varnish product showed the most favorable results.