One of the methods for whitening teeth uses a ‘tray’. First of all, impressions are taken … … from which a study model is made. This is painted with a special material … … which increases the thickness of the tooth area. When the tray is prepared, a small pocket is produced. The whitening solution occupies this pocket … … ensuring that it only comes into contact with the required surfaces … … and that no damage is done to the soft gums.