Invisalign aligners don't feel the same in your mouth all the time. While you may be used to each set feeling tight to start with, you may be surprised when your current set starts to feel looser than other sets have in the past.
Why does this happen, and do you need to do anything about it?
Changes in Your Teeth Affect Aligner Fit
Typically, each set of aligners feels tight to start with. The fit may even be a bit uncomfortable. This is normal. The tightness of each aligner is specially designed to move some of your teeth into their next position through pressure.
As your teeth move, your aligners feel more comfortable. Generally, you won't then notice them much if at all. However, sometimes, aligners start to feel loose. This loosening usually simply means that your teeth have moved and that the aligners have done their job. When your teeth move, the aligners don't press on your teeth in the same way any longer. So, they lose some of their initial tightness.
This doesn't necessarily happen with every set of aligners you wear, and loosening may take place at different times. For example, sometimes aligners feel loose quite quickly after you start wearing them; other times they only feel loose just before you need to change to a new set.
What to Do About Loose Invisalign Aligners
Given that it's normal for aligners to feel loose as they work, you may find that this isn't much of a problem. You may just get used to the new fit.
While loose aligners may indicate that the set has moved your teeth in the right way, this doesn't necessarily mean that you should just switch to using your next set on the basis that you're ready to move on. You shouldn't do this until your dentist tells you to. Even though your aligners feel a little looser because they've moved some of your teeth, they may still have work to do in other areas of your mouth. If you switch sets too soon, you could delay or harm the way all your teeth are meant to move. Also, you may find that your next set of aligners don't fit as well if your current set hasn't completed all its movements.
If your aligners are so loose that you're having trouble keeping them in, then contact your dentist. Depending on how long you've been wearing this set, they may tell you to start your next one. Or, they may want to see you to check that the aligners aren't damaged or that you haven't developed a problem with your teeth.
For more information about Invisalign aligners, contact your dentist.