The sodium fluoride alone will probably not do the trick. The most common treatment most dentists will use to remove white spots from teeth is called microabrasion. Microabasion is performed by mechanically removing the white spot, after which dental bonding may be performed over the area. Teeth Whitening may be used following microabasion to enhance the results.
If there are large white spots on teeth and microabrasion is not a viable option, a porcelain crown or porcelain veneer might be required to cover white spot(s). A cosmetic dentist is the ideal canididate to fix the problemfor. If many teeth have large white spots, all of the discolored teeth may need to have crowns placed. This can be quite costly in light of the fact that white spots are generally only of cosmetic concern and do not affect the health of the tooth.
If your teeth are suffering from decalcification, then fluoride and a product called A-C-P (anhydrous calcium phosphate) can be used to remineralize the enamel. These ingredients are found in a prescription strength toothpaste made by 3M called Clinpro 5000. Typically you would get this from your dentist along with custom whitening trays. I recommend my patients wear the trays over night every night for two weeks with a thin layer of the Clinpro 5000 lined inside the whitening trays. I have them come in for an evaluation and detemine how things are progressing. I will then have them start teeth whitening for 30 minutes per day and continue the Clinpro overnight therapy for two weeks. We re-evaluate and determine if the results are satisfactory. If not, the two choices are to either continue the whitening and Clinpro therapy and re-evaluate or perform microbrasion and continue whitening and Clinpro therapy. Microbrasion of the demineralized enamel may be necessary to achieve the desired results. Microbrasion is removal of a thin layer of undesireable enamel on the outer surface of the tooth. The idea is to remove this unwanted portion of the enamel surface exposing healthy enamel.
Just a thought… some white spots are caused by too much fluoride exposure during tooth development. This is called fluorosis and it can be treated very similarly to demineralization. I have also found that teeth whitening alone disquises fluorosis and the teeth look nice and white. The whitening works on the tooth structure not affected by the fluorosis leaving less contrast between the dark and light – white spots are less noticeable because the rest of the tooth is white. The is also a product called MI Paste which has the remineralizing ingredients – A-C-P without the fluoride. This is what I use instead of Clinpro 5000 when treating fluorosis.