The first method, In-Office Whitening, involves the carefully controlled use of a relatively high-concentration peroxide gel (35-37%), applied to the teeth by the dentist. Generally, the peroxide is applied to the teeth for two 15 to 20 minute intervals that add up to an hour (at most). Bleaching can cause a temporary increase in sensitivity that lasts no longer than a day or two. Those with particularly stubborn staining may be advised to return for one or more additional bleaching sessions, or may be asked to continue with a home-use whitening system. During this treatment an ultraviolet lamp could be applied as well, to increase the whitening result.
The second method, Professionally Dispensed Take-Home Whitening Kits, use the custom-made bleaching trays molded to the patient’s teeth. The whitening gels we use in our clinic are based on hydrogen carbamide concentration of 15%, and are used for 15 days at home. Most dentists believe professionally dispensed take-home whitening kits are a better option since the bleaching results last over the long haul.