[header] How to make a fake retainer out of wax [title] Learn about damage to teeth. [step] A dental retainer works by applying pressure to your teeth. If this pressure is applied wrong, the result might be wearing away the enamel of the tooth's surface-and this is the least of the problems. 
If the pressure forces your tooth too much in one direction, bone resorption can occur and cause the tooth (or teeth) to become loose. You can also impact the blood flow to the tooth, which causes the tooth to die.