the typical tray-based teeth whitening system (like those dispensed by dentists to their patients) involves the use of clear plastic trays (termed “custom” trays) that have been fabricated and adjusted so they fit comfortably over the patient’s teeth. These whitening trays are then sent home with the patient along with a quantity bleaching gel (typically a 10% carbamide peroxide whitener).
When performing their treatments, the patient places whitener into their bleaching trays and then seats them over their teeth. The trays are worn for multiple hours per day (or else overnight), for a series of days or weeks (per the dentist’s and manufacturer’s instructions), as the effects of the whitening process take place.