Most dentists offer in-office and home bleaching options for whitening teeth. A recently published study (Journal of the American Dental Association) compared the results of bleaching at home with custom dental trays (made from molds of the teeth) and a more concentrated bleaching formula applied in the dental office. When the study participants were reevaluated after 9 months, there was no statistical difference between the two groups. The primary benefit of in-office bleaching is much faster results.