Whitening strips are strips of plastic that adhere to the front of teeth and apply a whitening gel to the teeth. They are sold at most pharmacies and range in price between 15-50 dollars. The whitening gel on the strips is similar to the type that is sold in most dental offices.
The Problems with Teeth Whitening Strips
Dr. Schafer doesn't recommend whitening strips because the strips do not mesh well with the teeth which causes two problems: because the whitening gels do not fit as well as a customized whitening tray, saliva touches the whitening gel causing it to break down quickly. The whitening gel is similar to hydrogen peroxide and if you place hydrogen peroxide in your mouth, you'll notice that it starts fizzing and bubbling. This fizzing and bubbling is the peroxide breaking down. In a similar way, when saliva is in contact with the whitening gel, it starts to lose it's potency and can quickly become useless. What generally happens is that the tips of the teeth whiten and the base of the teeth do not.
The second problem is that the gels can be very concentrated and can easily burn the gums if the strips are misplaced. Peroxide burns do not show up immediately and between two or three minutes to show up, and by this time, the damage has already been done. While these burns will heal in a few days, they sting in the meantime. If you burn your gums, Dr. Schafer recommends warm salt water rinses as well as whatever over the counter pain medication works best for you.