You may have seen recent headlines about plastics in dentistry, especially a piece in The Atlantic suggesting that clear aligners and retainers could be a source of microplastics. Understandably, many patients have asked us:
“Are my Invisalign (or other clear aligners/retainers) safe?”
The reassuring answer: yes, current evidence supports that aligners and retainers are safe for routine use. Millions of people worldwide have worn them for decades with no proven health harms. Like any medical device, it’s smart to understand the science and follow good care habits, but there’s no reason to be alarmed.
What the Science Actually Shows
- Medical-grade materials: Most aligners (like Invisalign’s SmartTrack) are made from FDA-approved, BPA- and phthalate-free thermoplastic materials. These plastics have been tested extensively for biocompatibility.
- Microplastic particles: Laboratory studies show that microscopic particles can be released when aligners are scratched or stressed — usually under artificial “accelerated aging” tests, not normal daily use in the mouth (Ryu et al., 2018; Shen et al., 2025).
- Chemical leaching: When aligners are soaked in harsh solvents in lab settings (beyond what is normal in the mouth), trace compounds can be detected. In saliva-like conditions, however, these levels are minimal to non-detectable (Ryu et al., 2018).
- Clinical relevance: A recent systematic review found no evidence of patient harm from aligner-related microplastics or chemical release in real-world use (Aljawad et al., 2025). Professional organizations continue to monitor the science, but aligners remain FDA-regulated and widely used safely worldwide.
How Aligners Compare to Everyday Exposure
Even if aligners release trace particles, they are a very small contributor compared to what we encounter daily:
- Indoor dust and air: Studies show that indoor environments contain hundreds to thousands of microplastic particles per cubic meter, making them a major source of what we inhale and ingest each day (Dris et al., 2016; Liao et al., 2021).
- Bottled water: A single liter can contain thousands of microplastic particles (Mason et al., 2018).
- Seafood: Mussels and oysters regularly contain microplastics from ocean water, meaning these enter our diet directly (Van Cauwenberghe & Janssen, 2014).
When compared, the contribution from aligners is tiny, a literal drop in the bucket compared to everyday dust, food, and water.
Practical Tips to Keep Aligners Safe and Effective
While the risk is minimal, these steps further reduce any theoretical exposure and keep your aligners working their best:
Do:
- Follow your replacement schedule. Old, scratched trays can break down more easily.
- Clean aligners gently with a soft toothbrush and mild soap or approved cleaners.
- Store them in their case when not in use.
- Rinse after removal to prevent buildup.
Don’t:
- Drink hot beverages while wearing aligners.
- Use boiling water, dishwashers, or harsh chemicals to clean them.
- Scrub with abrasive toothpaste or hard brushes.
For retainers:
- Plan on periodic replacement of clear retainers if worn nightly for years.
- Consider signing up for a retainer subscription program that makes it easy to replace your retainers annually.
The Bottom Line
Yes, microplastics are everywhere, but aligners and retainers contribute only a very small fraction of what we’re already exposed to through air, water, and food daily. After more than two decades of use in millions of patients, there’s no evidence they cause harm. The health benefits of orthodontic care, including improved bite, easier hygiene, healthier airways, and a confident smile, far outweigh any theoretical risks.
At McComb Orthodontics, your safety is our top priority. If you have concerns, our team is always here to discuss options and help you feel comfortable with your treatment.
References
Aljawad A, et al. Can clear aligners release microplastics that impact the patient’s overall health? A systematic review. Journal of Clinical Orthodontics. 2025.
Dris R, Gasperi J, Saad M, Mirande C, Tassin B. Synthetic fibers in atmospheric fallout: A source of microplastics in the environment? Marine Pollution Bulletin. 2016;104(1-2):290-293.
Liao Z, Ji X, Ma Y, et al. Airborne microplastics in indoor and outdoor environments of a coastal city in China. Environmental Science & Technology. 2021;55(4):2603-2610.
Mason SA, Welch VG, Neratko J. Synthetic polymer contamination in bottled water. Frontiers in Chemistry. 2018;6:407.
Van Cauwenberghe L, Janssen CR. Microplastics in bivalves cultured for human consumption. Environmental Pollution. 2014;193:65-70.
Ryu JH, Lee MJ, Jeong SH, Hwang CJ. Effects of mechanical and chemical degradation on the surface properties of orthodontic aligners. Korean Journal of Orthodontics. 2018;48(5):316-325.
Shen C, et al. Evaluation of microplastic release from orthodontic clear aligner: a spectroscopic study. APOS Trends in Orthodontics. 2025;15(3):213-221.
Zhang H, et al. Cyclic loading-induced fatigue of clear aligners and potential microplastic release. Proceedings (MDPI). 2025;85(1):16.
