I have no personal experience with teeth whitening products. But, if you have AOL, click on the "Video @ AOL" icon and select SEARCH, then type in "teeth whitening" to view the video, "America's Obsession with Whiter Teeth". That video will discuss some concerns about teeth whitening and possible negative effects. The video is a CNN video by Dr. Sanjay Gupta, but I couldn't find it when I went to cnn.com.