Everyone who opts for teeth whitening will see some kind of improvement in brightness and whiteness of their teeth. Nevertheless, you must remember that teeth whitening is NOT a permanent solution..
The causes of tooth staining are age, inborn tooth colour, enamel thinness, eating habits, smoking habits, drug/chemicals, etc.
Significant colour change in a relatively short period of time is a major benefit of having teeth whitening at a dentist.
Patients with particularly stubborn staining may have to return for one or more additional teeth whitening sessions.