There are two different techniques for tooth whitening.
Home Whitening
Patients who choose to whiten their teeth at home generally have custom-made whitening trays made by the dentist. These trays fit precisely to your teeth to help provide even exposure. The active whitening agent is hydrogen peroxide or carbamide peroxide. No harm is done to the teeth as they are essentially “cleansed” beneath the enamel layer. There are generally no side effects although some people may have temporary tooth sensitivity or temporary irritation of the surrounding soft tissue. In these cases, patients should discontinue whitening until the sensitivity and/or irritation improves. Otherwise 10-14 days of one-hour whitening sessions are generally sufficient.
Office Whitening
In-office whitening is very similar to whitening at home except the whitening agent used will generally have higher concentrations of the peroxide. These higher concentration gels are stronger so they can only be used as a prescription material by the dentist. The office procedure requires lip and cheek retractors and a barrier placed over the adjacent gum tissue. For the best results it is generally recommended that the patient follow up with home bleaching. This allows the patient to maintain the results from the in-office treatment over the long term.