The application of a self-assembling peptide on noncavitated caries lesions is supposed to be a feasible approach to facilitate remineralization and mask their unfavorable appearance. However, demineralizing conditions are common in the oral environment, so the aim of this pH-cycling study was to compare recommended and novel treatment methods regarding their ability to hamper demineralization and as a consequence mask artificial enamel caries lesions. Artificial caries lesions were prepared in bovine enamel and randomly allocated to 11 groups (n = 22). Treatments before pH-cycling were as follows: the application of a self-assembling peptide (Curodont™ Repair [C]), a low-viscosity resin (Icon® [I]), 2 fluoride solutions (10,000 ppm F^-: Elmex fluid [E] and 43,350 ppm F^-: Tiefenfluorid® [T]), and no intervention (N). During pH-cycling (28 days, 6 × 60 min demineralization/day) half of the specimens in each group were brushed (10 s; 2 ×/day) with either fluoride-free (named e.g., C₀) or NaF (1,100 ppm F^-; e.g., C₁) dentifrice slurry. In another subgroup specimens were pH-cycled but not brushed (N_NB). Differences in integrated mineral loss (ΔΔZ), lesion depth (ΔLD), and colorimetric values (ΔΔE) were calculated between values after pre-demineralization, surface treatment, and pH-cycling. Specimens of C₀, C₁, N_NB, N₀, N₁, T₀, and E₀ showed significantly increased ΔZ and LD values after pH-cycling (p ≤ 0.003; paired t test). C₀, C₁, N_NB, and N₀ showed significantly higher changes in ΔΔZ than E₁, I₀, I₁, and T₁ (p < 0.001; ANOVA). Significantly reduced colorimetric values could only be observed for I₁, I₀, E₁, and E₀ after treatment and after pH-cycling (p ≤ 0.027; paired t test). In conclusion, under the conditions chosen only the application of a low-viscosity resin could mask caries lesions significantly, whereas self-assembling peptides could neither inhibit lesion progression nor mask the lesions considerably.