Teeth bleaching gels are often produced from the compound carbamide peroxide. The active component in this compound is hydrogen peroxide, which is usually a bleaching agent. This could be the chemical cosmetic dentists use to bleach your teeth. The difference is the fact dentists are likely to make use of larger concentrations of carbamide peroxide (all-around 15-35%) than identified in usual teeth bleaching teeth whitening gel goods offered in the stores (all-around 3%). From the old days, these gels were very complicated to apply, but currently gels arrive with custom-fitted application trays, and some even produce bleaching pens, which are handy when applying the teeth whitening gel on the teeth. http://www.gather.com/viewArticle.action?articleId=281474977950982