You can only do this experiment if you can get hold of an old tooth, for example, if one of your milk teeth has recently come out. Don't try pulling them out of anyone's mouth, leave this for dentists to do! If you can't get hold of an old tooth then try the coin experiment below.
Put the tooth in a glass of Cola and leave it for a few days. You will see the tooth is slowly eaten away. The Tooth Fairies will be disappointed with such a grotty tooth so make sure you get your reward from under your pillow before you do the experiment.