Depending on the look you desire, you may need to be keep the gel on longer. If your teeth are fairly close to your desired color, then you will only need to be in the chair for a short period. Typically, it takes about an hour to accomplish a whiter smile.
One advantage of laser teeth whitening is that you only need one visit to see a visible difference in the color of you teeth. In some extreme cases, additional laser treatments may need to be done to achieve the desirable color you are looking for.
A major disadvantage of laser teeth whitening is the cost. Compared to other methods of teeth whitening, laser teeth whitening can be dramatically higher. Laser whitening generally begins around $1000. However, depending on the number of treatments needed, the cost could be considerable higher.
Another disadvantage that is sometimes associated with laser whitening is sore teeth and gums. This is because of the bleach used to whiten the teeth. Generally speaking, this is only a short term problem.
by: Timothy Croy