Teeth whitening is the process of removing staining from the teeth using a bleaching agent that gradually whitens the teeth. To complete this process at home, custom bleaching trays are fabricated for the patient by making impressions of their teeth.  Once bleaching trays have been fabricated, the patient is given a bleaching agent with all of the treatment instructions to follow at home and progress is monitored by the treating dentist at periodic visits.  The length of treatment can vary dependent on the desired results and degree of staining for each patient.