Night guard materials & safety
Do Night Guards Release Microplastics? What Current Research Actually Shows
Updated September 1, 2026 to reflect recent research on micro- and nanoplastic release from dental polymers.
Plastic oral appliances spend hours in a warm, wet environment while being exposed to biting, clenching, grinding, cleaning, and everyday wear. It is reasonable to ask whether that wear can release microscopic plastic particles—and what those particles might mean for your health.
Research now shows that some dental polymers can release micro- and nanoplastic particles under laboratory conditions. A 2026 study detected particles from all six orthodontic materials it tested. However, the study did not test Sentinel's specific night guard materials, did not measure real-world exposure from people wearing night guards, and did not show that night guard use causes disease. The science is evolving, and those distinctions matter.
First: what are microplastics and nanoplastics?
Microplastics are small solid plastic particles generally measuring less than 5 millimeters. Even smaller particles—typically below 1 micrometer in the terminology used by recent dental research—are often described as nanoplastics.
These particles can originate when larger plastic materials break down through mechanical, chemical, or environmental processes. That is why researchers have begun looking closely at products that remain in the mouth for long periods, including clear aligners, retainers, splints, and other polymer-based dental appliances.
The evidence in context
What we know—and what we still don't
Recent laboratory research has detected micro- and nanoplastic particles from several dental polymers.
Researchers have not established how much a typical night guard wearer would ingest or absorb during normal use.
Current studies do not establish that wearing a dental night guard causes a particular disease or health condition.
What did the newest dental-polymer study find?
In February 2026, researchers from the University at Buffalo and University of Pittsburgh published a study in Progress in Orthodontics examining particle release from six polymers used in orthodontic appliances.
The researchers tested three directly printed materials and three thermoformed materials. Equal-sized samples were kept in artificial saliva for one week and agitated daily. The released particles were then measured and studied in the laboratory.
The study found measurable micro- or nanoplastic release from every material tested.
Direct-printed polymers generally produced higher particle concentrations than the thermoformed materials tested.
The thermoformed group still released particles, with much of that release occurring in the nano-sized range.
Macrophages took up particles in laboratory cell experiments, and some materials produced a more pro-inflammatory cell response.
Read the peer-reviewed study: Orthodontic derived microplastics impact macrophage differentiation and homeostasis .
What this study does not tell us: it does not tell us that wearing a night guard causes inflammation in a person, that all dental plastics behave the same way, or how much exposure occurs during years of actual night guard use.
Was this study actually about night guards?
Not specifically.
The researchers studied polymers used in orthodontic appliances, including materials associated with aligners and retainers. The paper also discusses broader applications of synthetic polymers in splints and sleep devices, but it did not test a collection of commercial night guards worn by patients over time.
That means the study is highly relevant to the broader conversation about plastic dental appliances, but we should not pretend it answers every question about every night guard material.
Do all night guards release microplastics?
We don't currently have enough direct night-guard research to answer that question with a simple yes or no.
We do know that plastic materials can experience surface wear, especially when exposed to repeated mechanical stress. We also now have direct laboratory evidence showing particle release from several polymers used in related dental appliances.
What we cannot responsibly say is that every night guard releases the same amount of particles—or that only inexpensive or worn guards release them.
Polymer chemistry, manufacturing method, appliance thickness, surface finish, wear pattern, cleaning practices, temperature, and the forces applied to the appliance could all potentially influence how a material behaves.
Does BPA-free mean microplastic-free?
No. These are two different material-safety questions.
BPA, BPS, phthalates and similar substances
These questions involve chemicals, monomers, additives, or plasticizers that may or may not be present in a particular material.
Microplastics and nanoplastics
These are physical polymer particles that can be generated or released from plastic materials. A product can be BPA-free and still theoretically release particles through wear.
If your primary concern is the chemical composition of a night guard—such as BPA, BPS, PVC, phthalates, MMA, or latex—see our separate Complete Guide to Night Guard Safety .
For a material-by-material explanation, see What Materials Are Used in Custom Mouth Guards? .
About Sentinel materials
What does this research mean for Sentinel night guards?
Sentinel's custom night guards are fabricated using thermoformed dental materials rather than directly printing the finished guard from photopolymer resin.
Used in Sentinel's soft Comfort Guard and as the inner layer of the Hybrid Guard.
Used in Sentinel's hard guards and as the outer layer of the Hybrid Guard.
Sentinel's current materials are also listed as free of BPA, BPS, MMA, PVC, phthalates, latex, and silicone. You can review our Materials & Safety information for the complete breakdown.
However, transparency requires an important caveat: the 2026 microplastics study did not test Sentinel's specific EVA or copolyester materials. We therefore should not use that study to claim that a Sentinel guard is “microplastic-free.”
What the study does suggest is that the composition and manufacturing method of a dental polymer can influence particle release—which makes continued material-specific research important.
Are microplastics from dental appliances dangerous?
That is the question researchers have not yet answered completely.
Micro- and nanoplastics are being studied across many areas of human health. Researchers have found associations between microplastic exposure and biological processes such as inflammation and oxidative stress, but human studies remain limited and cannot yet establish clear cause-and-effect relationships for many specific diseases.
The 2026 dental-polymer study adds an important piece of evidence because some appliance-derived particles were taken up by macrophages in cell culture, and certain polymers affected macrophage behavior.
But cell-culture results are not the same as clinical outcomes in people. The dose, duration of exposure, particle size, polymer type, and the body's ability to clear particles are all relevant to real-world risk.
A 2024 review focused on orthodontic aligners reached a similarly cautious conclusion: concern is reasonable, but better evidence under realistic clinical conditions is still needed.
Can you tell if your night guard is releasing microplastics?
Not by looking at it.
Micro- and nanoplastics are too small to identify reliably with the naked eye. A cloudy guard, rough texture, bite marks, or visible wear does not prove that you are being exposed to a specific quantity of microplastics.
Those physical changes still matter for another reason: they can tell you that the appliance itself is wearing down.
Consider having your guard evaluated or replaced if it develops:
- Holes or areas that have become very thin
- Deep grinding grooves
- Cracks or fractures
- Sharp or rough edges
- A significant change in fit
- Material separation in a laminated appliance
If yours has reached that point, see My Night Guard Broke: What You Should Do .
Should you replace a night guard just because you're worried about microplastics?
There is currently no evidence-based universal replacement interval designed specifically to prevent microplastic exposure.
That means we do not recommend throwing away a well-fitting, functional dental appliance simply because a particular number of months has passed.
Replacement decisions are better based on the material, your grinding severity, fit, structural wear, hygiene, and guidance from the manufacturer or your dental professional.
What can you reasonably do if you want to minimize unnecessary wear?
We don't have evidence that any home-care routine can make a plastic oral appliance “microplastic-free.” But it does make sense to avoid practices that unnecessarily damage or abrade the material.
Do
- Follow the cleaning instructions for your specific appliance.
- Use cool or lukewarm water.
- Clean gently rather than aggressively scrubbing the surface.
- Inspect the guard periodically for structural wear.
- Ask the manufacturer what material your appliance is made from.
Avoid
- Boiling or very hot water unless your appliance specifically requires heat molding.
- Abrasive toothpaste or gritty cleaners.
- Harsh household chemicals.
- Continuing to wear an appliance that is cracked, fractured, or badly worn without having it evaluated.
For appliance-specific care instructions, visit our Complete Guide to Cleaning Your Night Guard .
The bottom line
Should microplastics stop you from wearing a night guard?
Based on the evidence available today, we don't think the science supports telling people with bruxism to stop using a properly selected dental guard because of microplastic concerns.
Untreated grinding and clenching can damage teeth, restorations, and dental work. A night guard is used to create a protective barrier between the teeth when that protection is clinically appropriate.
At the same time, it would also be inaccurate to say that dental polymers are completely incapable of releasing microscopic particles. Recent research tells us otherwise.
The most defensible position is somewhere in the middle: use an appropriate, well-characterized dental material; care for the appliance properly; replace it when wear compromises its condition or function; and keep following the research as better real-world evidence becomes available.
If you are deciding between different night guard materials, you can compare Sentinel's custom night guard options here .
Frequently asked questions
Do night guards contain microplastics?
A finished plastic night guard is a polymer appliance, not a product intentionally filled with loose microplastics. However, research on related dental polymers shows that micro- and nanoplastic particles can be released from some materials under laboratory conditions.
Do all night guards shed microplastics?
We do not yet have enough direct, material-specific night guard studies to make that claim. A 2026 laboratory study detected particles from all six orthodontic polymers it tested, but those results should not automatically be generalized to every night guard material and brand.
Are thermoformed night guards microplastic-free?
No such claim can currently be made. In the 2026 orthodontic-polymer study, the thermoformed materials tested also released particles, although direct-printed materials generally produced higher concentrations and more micro-sized particles.
Does BPA-free mean a night guard doesn't release microplastics?
No. BPA content and microplastic release are different issues. BPA is a chemical-composition question, while microplastics are physical polymer particles. A BPA-free material is not automatically particle-free.
Are Sentinel night guards microplastic-free?
Sentinel does not make that claim. Our night guards are fabricated from dental thermoforming materials including EVA and copolyester, but the available research has not specifically tested our finished appliances for real-world micro- or nanoplastic exposure.
Should I stop wearing my night guard because of microplastics?
Current research has not established that wearing a night guard causes disease from microplastic exposure. If your guard is being used to protect teeth from significant grinding or clenching, discuss any concerns with your dentist rather than discontinuing an appliance you need based solely on laboratory findings.
How do I know when my night guard needs replacing?
Look for meaningful structural changes such as holes, severe thinning, cracks, sharp edges, delamination, or a change in fit. There is not currently a universal replacement schedule based specifically on microplastic exposure.
Research & references
- Warunek J, et al. Orthodontic derived microplastics impact macrophage differentiation and homeostasis . Progress in Orthodontics. 2026.
- Panayi N, et al. Microplastics and orthodontic aligners: The concerns arising from the modernization of practice through polymers and plastics . Journal of the World Federation of Orthodontists. 2024.
- Ririe AK, et al. Impact of Microplastic Exposure on Human Health: A Systematic Review of Mechanisms, Biomarkers, and Clinical Outcomes . 2025.
- World Health Organization. Dietary and inhalation exposure to nano- and microplastic particles and potential implications for human health .
This article is for educational purposes only and is not intended to diagnose, treat, or replace individualized medical or dental advice. Microplastics research is evolving, and this page may be updated as new dental-appliance evidence becomes available.