Do clear dental aligners like Invisalign release microplastics into your mouth?

What's actually in it

Clear dental aligners, retainers, night guards, and oral splints are made from polyurethane, polyethylene terephthalate (PET), or copolyester plastics. You wear them pressed against your teeth and gums for 20 to 22 hours a day, surrounded by warm saliva that acts as a constant solvent.

Over time, chewing, grinding, and normal wear create friction that breaks off tiny pieces of plastic. These fragments range from microplastics (visible under a microscope) to nanoplastics (too small to see). You swallow them along with your saliva, day after day.

What the research says

A 2026 review in Quintessence Int examined whether oral splints, clear aligners, and similar devices are hidden sources of micro- and nanoplastic exposure. The researchers concluded that these devices can indeed release plastic particles into the mouth during normal use.

The oral cavity is a harsh environment for plastic. Temperature changes from hot and cold drinks, mechanical stress from biting and grinding, and the chemical activity of saliva all accelerate degradation. Each time you eat, drink, or clench your jaw, tiny particles can break free.

Once swallowed, microplastics travel through the gut. Nanoplastics are small enough to cross the gut lining and enter the bloodstream. Research on microplastic exposure has linked it to gut inflammation, oxidative stress, and immune system changes.

If you wear aligners or a night guard, rinse them with cool water (not hot) after removal. Replace them on schedule rather than wearing them past their intended life. Avoid eating or drinking hot beverages while wearing them. And clean them with a soft brush, not abrasive cleaners that can scratch the surface and increase particle release.