Bleaching and whitening has been a Hollywood smile staple for decades, but the harsh agents, techniques, and whiteners used in the past bear little resemblance to current professional techniques. You lose years of yellow aging and get a beautiful smile quickly. It's easily the best bang for the dental buck. These demand careful in-office application around dental dams, which prevent adjacent gums from temporary discoloration. This process whitens the teeth dramatically and immediately.
Many dentists say their effects last longer.
The dentist creates a custom soft plastic tray that fits around the teeth precisely. Purchased at drugstores, these feature a tray which is heated in water to make it malleable. The user then puts the tray in his or her mouth and bites down to create a form that fits. Unfortunately, self-impressions can be loose and irregular, producing an uneven tray. In turn, the bleaching gel settles unevenly and portions of the teeth may remain yellowed.