Invisalign is a non-fixed, teeth-straightening treatment that was developed in 1997 as an alternative to fixed treatments like braces and metal retainers. Besides their clear, unobtrusive design, another major benefit is that you can take your teeth aligners out to play sport, eat your meals, or to clean or floss your teeth. They can therefore be more hygienic than fixed, traditional treatments. However, you should keep them in at all other times to get the best results, including when you’re sleeping. This means that you should have them in for about 22 hours per day.  It’s important to understand that Invisalign is also a progressive treatment. You receive a new set of custom-made aligners once recommended by a dentist. The aligners are made of clear, medical-grade plastic that gradually shift your teeth to a new position. Each set of aligners builds on the work done by the previous set, and individual teeth can be targeted, unlike traditional braces that tend to move all your teeth at once. Invisalign treatment is usually less painful than wearing traditional metal braces. There are no metal brackets to be attached to your teeth or wires to be tightened when you have an Invisalign treatment to straighten your teeth instead.