I found the article "Tooth Whiteners Weaken Enamel" (C&EN, Dec. 19, 2005, page 49) of great interest. I am an oral hygiene researcher and have been discussing the inherent problems associated with the bleaching practice with my colleagues. I applaud Michelle E. Dickinson for coming forth with her findings as a warning of potential dangers down the road. Not only is enamel erosion a problem, but far greater is the growing incidence of sensitivity. Constant bleaching with high levels of peroxides will lead to hypersensitive teeth. Also, high levels of peroxides will lead to gingival irritation in some people.
I believe it is important to analyze all risks and potential risks before pursuing tooth bleaching or anything like it. Let's be clear here: We are not whitening teeth; that is impossible. One's enamel color is inherited and cannot be changed. What is actually happening is stain removal and bleaching. The criterion for a whitening claim by the American Dental Association is not color change but stain removal. I think the public has been misled in this respect, and greater education by the professional dental community is needed. The potential dangers are real, as indicated by your article.
Roger E. Stier