Introduction: To compare the effects of 0.05% sodium fluoride (NaF) mouthrinse, GC Tooth Mousse and GC MI Paste Plus on white spot formation inhibition. Materials and Methods: Thirty pairs of extracted human premolars were cut in half mesio-distally with a disc. The teeth were coated with nail varnish, except a part of the buccal and/or lingual enamel, which was used as the test area, and then divided into 4 groups randomly: A) control, B) 0.05% NaFmouthrinse, C) Tooth Mousse, D) MI Paste Plus. Therapeutic agents were applied once daily following the manufacturer’s directions in a PH-cycling model over 35 days. At the end of the experiment, all the specimens were examined in order to detect white spot formation before and after drying (scoring 0-2). Mann Whitney test was used for statistical analysis. Results: The mean of the white spot scores in groups B (0.16), C (1.4) and D (1.2) were significantly lower than group A (2). Significantly lower mean of white spot scores was found in NaFmouthrinse group compared with two other products. No significant difference was observed between Tooth Mousse and MI Paste Plus. Conclusion: Although 0.05% NaF mouthrinse, GC Tooth Mousse and GC MI Paste Plus are effective preparations to inhibit white spot formation, NaFmouthrinse has better efficacy than CPP-ACP (casein phosphopeptide-amorphous calcium phosphate) products.