Tray whitening: what the evidence shows.

In recent years, many dental professionals have changed their philosophy regarding the use of trays with at-home bleaching regimens. However, facts do not change--and successful vital tooth bleaching still occurs only when tooth surfaces are in direct contact with the appropriate concentration of active whitening agent for a specific amount of time. Because the science of tooth whitening is still in its infancy--this article reviews a series of remaining questions regarding vital tooth bleaching based on current scientific information and research findings on products using trays.