There will be times when the retractors will be used as well, and this is important so that your lips and tongue will not get in contact with the whitening agents incorporated in the solution. Next up is the addition of the barrier on the gum line. This is done so that the whitening solution will not get in contact with the gum area. Because of this, the market is being flooded with different brands every time and because it is one of those procedures that are fast and effective without the pain (mostly), it is so very easy to ride the bandwagon; yet, side effects could happen even adversely if unbeknown to the customer, the products are not used as indicated. For persons with sensitive teeth though, toothpastes containing potassium nitrate are recommended. Even without specialty toothpastes, the sensitivity is usually over in two days. However, persons with recessed gums, faulty tooth restoration and cracked teeth are more likely to encounter shooting pains. It is not entirely true that using bleaching agents containing such reduces the enamel of the teeth over time. If it does, it is actually very negligible and so does not have adverse effect on the tooth. Sure there could be, in some cases, mild irritation and tooth sensitivity during the initial stages but these usually are gone after a few days of treatment. And the differences between the two categories are assessed using the following measures: Composition and the strength of the bleaching agent used. It is an accepted fact that the over the counter medications and formulations will contain less concentration of the bleaching agent. In many products, the concentration will only reach up to 10 percent. What To Remember When Shopping For Teeth Whitening Paste Many studies have it- teeth whitening pastes that are available in the supermarket works and are safe. And when used properly, say twice daily the expected effect by the person can be realized in as a short as two weeks. And everyone can even increase the chance of being in the safe side if they can shop for the whitening tooth paste that is approved by the American Dental Association.