Teeth whitening (bleaching) is the most common cosmetic dental procedure. This treatment recommended procedures for brightening discolored teeth. Aging process and a lifestyle can stain and darken teeth. Many things can contribute to stained teeth, such as drinking coffee, tea, and smoking. There are two methods for brightening teeth, in office bleaching (using laser teeth bleaching) and at-home teeth bleaching (using take-home bleaching tray). In office bleaching is a good method for sensitive teeth, because the process may be closely watched by dentist. In case you already have veneers, or crowns teeth bleaching will not act on these and you need to have a look at replacements.