Plastic Night Guards

My Biological Perspective

HEALING FOUNDATIONSAIRWAY & DEVELOPMENTBIOLOGICAL DENTISTRY

Shannon Korczynski

7/4/20266 min read

A few weeks ago, my Heal Teeth Naturally Facebook group reached an exciting milestone of 1,000 members. And to celebrate, I invited members to ask their biggest questions about biological dentistry and promised to answer each one in greater detail.

The very first question came from my longtime friend, Veronica.

"How do you feel about plastic night guards used for grinding and TMJ?"

I smiled because I knew there wasn't a simple yes or no answer.

If you've followed me for any length of time, you know I try to minimize unnecessary synthetic materials whenever possible. So you might assume I would tell everyone to avoid a plastic night guard.

That isn't my answer.

In fact, I wear one myself.

I have an airway restriction that contributes to nighttime clenching and grinding. I currently wear a hard acrylic night guard to protect my teeth from tooth-to-tooth damage while I continue addressing the underlying reason my body feels the need to grind.

Do I love wearing it? No.

Do I believe it has solved the problem? Absolutely not.

I see it as a temporary tool that protects my teeth while I work toward a better long-term solution.

That philosophy carries into everything I do in biological dentistry.

Sometimes we need to protect the body while creating the opportunity for it to heal.

Before we go any further, let's clear up one point of confusion.

We all have TMJs.

TMJ stands for temporomandibular joint, the hinge connecting the lower jaw to the skull. It is part of our normal anatomy. When that joint or the surrounding muscles become painful or dysfunctional, the diagnosis is temporomandibular disorder (TMD).

Most people say they "have TMJ," but technically they are describing TMD.

A night guard can be an excellent appliance when it is used for the right reason. If someone is wearing away enamel, fracturing teeth, breaking restorations, or placing excessive stress on the jaw joints, I absolutely want to protect those structures.

Enamel does not grow back, and chronic overload of the temporomandibular joints can eventually damage the articular disc and supporting tissues.

One thing I think is often misunderstood is that a night guard does not stop you from clenching or grinding.

Your jaw muscles are still contracting.

Your nervous system is still following the same pattern.

The appliance simply changes what you're clenching or grinding against.

Instead of tooth against tooth, the force is distributed across the appliance. Depending on the design, it may also reduce excessive loading within the jaw joints, helping protect the articular disc while reducing compressive forces on the surrounding structures. That protection can be incredibly valuable, but it should never be mistaken for treatment of the underlying cause.

Where my philosophy differs from conventional dentistry is what happens after the appliance is delivered.

Too often, the patient wears it for years, eventually grinds through it, another one is made, and the cycle repeats. The teeth may be protected, but no one asks why the body continues to grind.

That is my biggest concern.

Over the past several years, airway has become one of the primary lenses through which I evaluate patients and clients. In my experience, oral structure and airway development are often central to the story. When breathing is compromised, the body adapts. Grinding and clenching may be part of that adaptation.

I also believe many of the downstream issues we commonly blame as "causes," such as chronic neck tension, nervous system dysregulation, poor sleep, postural compensation, mineral depletion, and ongoing inflammation, are often consequences of a body that has been adapting for years. That deserves an entire article of its own, so I'll leave it there for now.

Let's come back to Veronica's original question.

What about the plastic?

Yes, I have concerns.

Every appliance placed in the mouth is exposed to warmth, saliva, enzymes, changing pH, and thousands of hours of chewing or grinding forces. Every material experiences wear over time. That means microscopic polymer wear particles, often referred to as microplastics, are likely generated regardless of the material used. While we don't yet have definitive research telling us how much chronic exposure from dental appliances contributes to the body's overall microplastic burden, I believe cumulative exposure matters and unnecessary exposure should always be minimized.

My concerns are less about "forever chemicals" specifically and more about the cumulative exposure to synthetic materials, proprietary additives, and microscopic wear particles generated over years of nightly use. Based on what we know today, the common materials used to fabricate night guards are not considered significant sources of PFAS, often referred to as "forever chemicals." However, manufacturers do not always disclose every component used in proprietary materials, and we still have much to learn about the long-term biological effects of chronic exposure to worn dental polymers.

At the same time, I also know that healthy tooth structure is irreplaceable.

If I have to choose between someone destroying healthy teeth every night or wearing a carefully selected appliance while we work to improve the reason it is needed, I will choose to protect the teeth.

The goal is not to avoid every material. It is to choose the least offensive, most durable material that will accomplish the job while continuing to pursue healing.

Heat-Cured PMMA Acrylic

This is the traditional hard custom night guard and, when a night guard is truly necessary, it is generally my preferred material.

Heat-cured PMMA acrylic has been used successfully in dentistry for decades. It is durable, stable, highly polishable, and far more resistant to wear than softer materials.

My concerns: No dental material is completely inert. Poorly processed acrylic can contain trace amounts of residual methyl methacrylate monomer, although proper laboratory processing greatly reduces this. Like any appliance subjected to years of grinding, microscopic wear particles are likely produced over time and may be swallowed. While the long-term biological significance of those particles has not been fully established, PMMA currently offers the best balance of durability, stability, and longevity in my opinion.

PETG (Essix-Type Appliances)

PETG is the clear thermoplastic commonly used for Essix retainers.

These appliances are excellent for maintaining orthodontic treatment but were never designed to withstand years of heavy bruxism.

My concerns: PETG scratches more easily, wears more quickly, and generally requires replacement sooner than hard acrylic. As it wears, microscopic particles are also likely generated. Long-term research on chronic exposure from prolonged nightly use remains limited.

Polyurethane (Vivera Retainers)

Vivera retainers are fabricated from a proprietary multilayer polyurethane material and are generally more durable than traditional clear retainers.

My concerns: Although more durable than PETG, they are still thermoplastic appliances intended for tooth retention rather than heavy grinding. Independent long-term data regarding wear particles and chronic exposure are limited.

EVA (Ethylene-Vinyl Acetate)

EVA is commonly found in athletic mouthguards, many soft custom appliances, and most over-the-counter "boil-and-bite" guards.

My concerns: This is my least favorite option for long-term nightly wear. Because EVA is soft and resilient, it compresses, wears more quickly, and gives the jaw something comfortable to bite into. In some people, that may actually encourage additional clenching or chewing. As it degrades, it also produces wear particles just like any other appliance.

The material, however, is only part of the decision.

The design of the appliance matters just as much.

Many dentists are trained to fabricate a night guard to protect the teeth, but if they are not evaluating the airway, they may not fully appreciate how the appliance influences the space available for the tongue during sleep.

An upper appliance occupies valuable room within the oral cavity. For someone who already has limited tongue space or a restricted airway, that additional thickness may make the appliance difficult to tolerate. Some patients unconsciously remove it during the night, while others struggle with gagging or simply cannot wear it consistently.

In other situations, a lower appliance may be the better choice. Depending on the individual's anatomy, it may provide a more favorable environment for tongue posture while still protecting the teeth and joints. There is no one-size-fits-all solution. The best appliance depends on the patient's anatomy, airway, bite, symptoms, and why they are grinding in the first place.

This is also why I don't recommend over-the-counter night guards. They are designed to fit everyone, which means they truly fit no one well. They tend to be bulkier, softer, and less stable than a properly fabricated custom appliance. If you genuinely need a night guard, I believe it should be custom made by a dentist who understands both occlusion and airway.

One final consideration is material compatibility. Every patient is different. While I generally prefer heat-cured PMMA acrylic based on its physical properties, patients with chemical sensitivities or a history of reactions to dental materials may benefit from additional evaluation before selecting any appliance.

So how do I feel about plastic night guards?

I don't love placing synthetic materials in the mouth.

I also don't love watching healthy teeth and jaw joints slowly deteriorate.

If a night guard is truly needed, I would rather see someone wearing a well-designed custom appliance fabricated from a durable heat-cured acrylic than continuing to damage their teeth every night.

My concern isn't simply what the appliance is made from.

My concern is believing that protecting the teeth means we've solved the problem.

My goal isn't to help people become lifelong night guard wearers.

My goal is to help them understand why their body needed one in the first place.

Over the next several months, I'll continue this conversation by exploring why we grind, how airway and oral structure influence the body, and why understanding the root cause is every bit as important as choosing the right appliance.

I hope this answers Veronica's question, but even more than that, I hope it encourages you to think beyond the appliance itself. A night guard may be exactly what you need today, but I also hope it inspires you to ask why your body needed it in the first place. That question is where healing begins, and it's the conversation we'll continue in future articles.

Plastic Night Guards

Heat-Cured PMMA Acrylic

PETG (Essix-Type Appliances)

Polyurethane (Vivera Retainers)

EVA (Ethylene-Vinyl Acetate)

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