Can you recommend a tooth whitenening product that I can dispense from my office, but is less expensive for the patient than custom trays or in-office bleaching?

There is a new product called Cavex Bite & White (Cavex Holland BV). It consists of a set of 10 upper and lower  trays and syringes of 16% carbamide peroxide gel with added desensitizers. The trays only have to be worn for one hour a day, and 19 of 20 patients reported noticeable whitening effects. This is an excellent way to dispense a fairly inexpensive, prescription strength bleaching system to patients.