Teeth whitening or bleaching procedure is done to remove the staining and whiten the teeth. Smoking, beverages like coffee, tea, and red wine usually cause staining of teeth. Normally, peroxide-based gels are used for teeth whitening procedure. Commonly used products are hydrogen peroxide and carbamide peroxide in varying concentrations. The procedure can be done in office or with a take home kit, which includes bleaching gels with custom trays.