The main portion of a tooth that is responsible for a tooth’s colour is the dentin layer, which is covered by the enamel layer of our tooth.  The whitening solution travels to the dentin layer and lightens this layer giving your tooth a whiter look.  Tooth whitening does not damage your tooth enamel.  It is very important that whitening instructions are followed, however.  Alterations in instructions or wearing whitening longer than suggested can make a tooth or a series of teeth sensitive.  It is always best to consult with your dental team if any concerns arise.