Active and Passive Retainers
Dental braces work very well and straighten your teeth to perfection. Sadly, when you don’t wear your retainer after your braces are taken off, your teeth might experience a relapse. Teeth can shift again and become uneven. Passive dental retainers fit passively over your teeth. They apply no pressure and have only one function: keep your teeth beautiful and straight after orthodontic treatment.
(Passive) retainers are designed to avoid orthodontic relapse. Spring retainers are currently used to keep teeth in the position that have been established after the braces have been removed. Simply wear the retainers at night, and you will keep your teeth straight. As an alternative, you can also have a fixed wire attached to the inside surface of your lower teeth.
Active retainers are used to move your teeth, therefore they are not passive but rather have an activated spring to push your teeth into the desired position. With such a retainer you can move front teeth, close gaps, and align your teeth. Active retainers have a limited indication and do not replace Invisalign or full braces.