Toothpaste and mouthwash question
At the lowest level of whitening products are toothpastes, floss and mouthwashes that have been specially formulated to brighten your teeth. Generally speaking, if used consistently, they can whiten healthy teeth about one shade over time. These products can be purchased over the counter, and may cost about the same as “regular” counterparts, or slightly more. Therefore, they are a cost-effective means of whitening your teeth, if you only wish to take off surface stains, and you are motivated to prevent stains from reoccurring in the future.
Whitening strips have become very popular in the past 5 or 6 years. They are easy to use and much less messy than bleaching kits. The cost is still significantly more than whitening toothpastes and products discussed above, but you will see more dramatic results more quickly. Besides cost, there are two additional drawbacks to mention with respect to strips. First, they only work on healthy teeth that have yellowed due to age and stains. Second, they may cause significant tooth sensitivity. Consult with your dentist before paying the $20-40 for one of these kits.
There are several major brands and formulations for whitening strips, including Crest, Listerine, Oral B and Rembrandt. Listerine’s strips dissolve in your mouth, which they claim to be a benefit because you don’t have to take them off 1/2 hour after you put them on. Crest Strips come in a variety of styles, including Daily Multi-care, which you use for only 5 minutes a day (brightening more slowly over time), and Crest Whitestrips Premium, which you only need to use for 7 days (1/2 hour morning and night). Most brands require use for 14 days, 1/2 hour morning and night.
These products contain hydrogen peroxide as a bleaching agent, and will only work on natural teeth; they will not whiten veneers or other dental work. Amounts of the bleaching agent differ, from 6% to 10%, depending on formulations.
Source: http://hubpages.com/hub/Whitening-Your-T…
You also may want to speak with your dentist should any side effects become bothersome. For example, teeth can become sensitive during the period when you are using the bleaching solution. In many cases, this sensitivity is temporary and should lessen once the treatment is finished. Some people also experience soft tissue irritation—either from a tray that doesn’t fit properly or from solution that may come in contact with the tissues. If you have concerns about such side effects, you should discuss them with your dentist