What is the difference between a 7-day teeth whitening strips kit and a 14-day teeth whitening strips kit?
The difference is in the concentration of peroxide that is present in them. The 14-day kit has a lower concentration and so it needs to be used for a greater number of days. The kits contain as many strips as are required, and there are strips for both the upper and the lower jaws. However, both kinds of strips need to be kept in contact with the teeth for at least thirty minutes everyday for twice a day. Depending on what you are looking for from whitening, Crest Whitestrips is a good choice and is the #1 dentist-recommended teeth whitening brand in the U.S.
