Due to their effectiveness and easy application, fluoride toothpastes are by far the most common form of caries control worldwide. In the fight against caries, fluorides in toothpastes are a powerful therapeutic agent. The use of fluoride toothpastes results in the deposition of alkalisoluble fluorides in the form of calcium fluoride-like globules. It is considered that calcium fluoride is the most important product formed on enamel after fluoride preparations are topically applied. The purpose of this paper is to show the effectiveness of different fluoride toothpastes on the deposition of alkali-soluble fluorides on the enamel surface, with respect to their interaction with the saliva of smokers and the saliva of non-smokers. As toothpastes of similar concentrations contain different fluoride compounds which have different abilities to release fluoride ions into the oral environment, it is considered that these differences in the solubility of different fluoride compounds could affect the amount of calcium fluoride formed on the enamel surface. Due to the organic fluoride carrier contained in them, amine fluoride toothpastes have shown to be more effective in remineralizing carious lesions when compared to toothpastes that contain monofluorophosphate and inorganic fluoride compounds. It was found that amine fluoride preparations achieve higher concentrations of fluoride in saliva when compared to sodium fluoride ones. Additionally, the formation of alkali-soluble fluorides has been demonstrated to be more efficient when using the amine fluoride toothpaste combined with the smokers’ saliva, and the effect of sodium fluoride toothpaste is not related to saliva at all.