For most people, the answer to this question is yes. You will need to wear a retainer after treatment. Unfortunately, teeth shift very quickly, and may even move back to their original position over time. Most dentists will require patients to wear a retainer at night to maintain the results achieved by the Invisalign treatment. However, this is not always the case. If you only need a slight correction to your teeth, you may not be required to wear retainers after treatment. The more drastic your correction, the more likely it is you’ll need to wear a retainer.