For in-office laser teeth whitening, a good two hours is needed to complete the procedure. Your hygienist will begin by making a record of your current teeth shade and taking impressions of your teeth to create custom-fitted trays. This will be followed by a gum protection procedure and the application of the whitening gel. Curing light or laser will be used to activate the bleaching agent. The teeth will rest with the solution for about an hour and can be reapplied occasionally until desired results are achieved. Once the best shade is reached, fluoride will be applied to ease any tooth sensitivity.