Mouthguards and how they protect teeth: A dentist-backed explanation

Dental mouthguards protect teeth by creating a tough, flexible barrier over teeth that helps prevent damage caused by a hit or fall.¹ The cushioning that a mouthguard — or mouth protector, sports guard, gumshield — provides can lower the chance of chipped, broken, or knocked-out teeth in contact sports and other activities. For nighttime teeth grinding or bruxism, dentists often recommend a night guard, which protects teeth during sleep.

Key takeaways:

• Mouthguards protect best when they fit well, stay in place, and allow normal breathing and speaking.

• Many professionals group mouthguards into three types: stock mouthguards, boil- and-bite mouthguards, and custom-fitted mouthguards.

• Custom-fitted mouthguards usually offer the most protection and comfort because a dentist makes them match the unique shape of the wearer's mouth.

• A sports mouthguard is not the same as a night guard — they protect against different risks.

• Mouthguards clearly help reduce dental and mouth injuries, while concussion protection remains a more debated topic across research and sports medicine discussions.

Which mouthguard do you need? (quick reference guide)

Quick clarification: A night guard does not replace a sports mouthguard during games or practice — and store‑bought guards do not treat sleep apnea.

How mouthguards protect your teeth — the mechanics

A mouthguard protects your teeth the same way a good bike helmet protects your head — it adds a layer that helps manage force, so the teeth and jaw do not take the full hit, preserving your dental health. A mouthguard for those who play sports fits over the upper teeth and creates a protective barrier between the teeth and lips.

1. Mouthguards absorb and redistribute impact forces

When a ball, elbow, or fall sends force toward the mouth, a mouthguard acts like a cushion. Instead of one tooth taking most of the pressure, the guard helps spread that force across a wider area, which can lower the chance of chips and fractures. This works best when the guard fits well and stays in place — a loose mouthguard cannot do its job as reliably.

2. Sports mouthguards keep upper and lower teeth from slamming together

Some dental injuries happen when the jaw snaps shut fast, and the teeth crash into each other. A mouthguard adds a buffer between the upper and lower teeth, which can help reduce damage from sudden tooth-on-tooth contact. This is one reason dentists may recommend different mouthguard designs depending on whether someone needs protection for sports impacts or for nighttime grinding and clenching.

3. Mouthguards protect lips, cheeks, and tongue from cuts

Mouthguards also help protect against a soft tissue injury inside the mouth. Without a mouthguard, the lips and cheeks can get cut if they get pressed against sharp tooth edges or orthodontic brackets during a hit. A properly fitted guard creates a smooth barrier that can reduce the risk of these cuts and scrapes.

4. Mouthguards for sports can help stabilize the jaw during sudden closure

During an impact, the lower jaw can move quickly, and that motion can add stress to the jaw joint and surrounding structures. Some sports dentistry research and discussions point to jaw positioning and stabilization as a potential benefit of certain mouthguard designs — but the details depend on fit and the specific design. That is one more reason a dentist-guided fit can matter for people with jaw pain, orthodontic hardware, or a history of dental repairs.

5. Do mouthguards prevent concussions? (what evidence suggests — and what it doesn’t)

Mouthguards clearly help reduce dental and mouth injuries, but concussion prevention is a more debated topic. Some newer research in specific settings has found an association between mouthguard use and lower concussion rates — for example, a large youth ice hockey study reported lower concussion rates and odds among players who wore mouthguards compared with non-wearers.² At the same time, sports medicine experts still describe concussion prevention as controversial and do not treat mouthguards as a guaranteed concussion solution.

A mouthguard is a smart move for protecting your overall oral health and smile. It should be part of a bigger safety plan that prevents dental emergencies while playing contact sports.

What injuries can a mouthguard help prevent?

A well-fitted mouthguard acts like a shock absorber for the mouth. It helps spread force from a hit or fall, so the teeth and soft tissues do not take the full impact.

• Chipped or fractured teeth: Mouthguards help absorb and redistribute impact forces, lowering the chance that a tooth cracks or fractures during hard contact.

• Knocked-out teeth (avulsions): Because the guard covers and cushions the upper teeth, it helps reduce the risk of teeth being displaced or knocked out during a collision.

• Cuts to lips/cheeks/tongue: A mouthguard creates a smooth barrier between the teeth and soft tissues, helping reduce cuts and abrasions — especially when playing contact sports or for those with braces.

• Jaw injuries from sudden closure: During an impact, the lower jaw can snap upward quickly. A mouthguard helps buffer this motion and may reduce the risk of injury from sudden tooth-on-tooth contact.

Different types of mouthguards (and which type is best for you)

1. Stock mouthguards (ready-made)

• Protection level: Lowest — limited protection because they can’t be adjusted and often fit loosely

• Comfort: Usually bulky and may make breathing or talking difficult

• Typical cost range: Low-cost (pharmacy/sporting goods store)

• Best for: Occasional or low-risk use; people who need a quick, inexpensive option

2. Boil-and- bite (mouth-formed)

• Protection level: Moderate — better coverage than stock because they mold to the teeth after heating

• Comfort: More comfortable than stock mouthguards but may still be uneven or bulky if molded incorrectly

• Typical cost range: Low- to mid-cost

• Best for: Youth athletes, recreational athletes, or anyone who wants a better fit without the cost of custom

3. Custom mouthguard (dentist-made)

• Protection level: Highest — made to someone’s exact dental shape and widely considered the most protective option

• Comfort: Best comfort and stability; designed to allow normal breathing and speaking

• Typical cost range: Higher cost due to dental fabrication

• Best for: Frequent athletes, people with braces, people with prior dental injuries, or anyone who needs the most dependable protection

When should you wear a mouthguard?

Wearing a mouthguard is one of the easiest ways to protect your teeth during activities that involve higher-impact risk or sudden jaw movement. The right timing depends on whether you're playing sports, grinding your teeth at night, or experiencing symptoms that need a dentist’s attention.

High-risk sports (contact, collision, and combat)

People should wear a sports mouthguard during any activity where a hit, fall, or collision is likely. Common examples include:

• Football, basketball, soccer, hockey, and lacrosse.

• Boxing, wrestling, and martial arts.

• Gymnastics, ice skating, biking, and skateboarding — activities with high fall risk even if not classified as contact sports.

These sports carry meaningful risk for chipped, broken, or knocked-out teeth, which is why dental associations strongly recommend a properly fitted mouthguard.

When a night guard may be recommended (grinding or clenching)

A night guard — which is different from a sports mouthguard — may be recommended when someone:

• Wakes up with jaw soreness.

• Shows signs of teeth grinding or clenching.

• Has worn-down enamel or unexplained fractures.

Night guards help protect teeth from the pressure and friction of grinding, which differs from impact protection.

When to talk to a dentist

A dentist should evaluate symptoms that suggest ongoing stress or medical concerns, including:

• Jaw pain or tightness, especially in the morning.

• Broken restorations (like cracked fillings or chipped crowns).

• Heavy or uneven tooth wear — a common sign of grinding.

• Suspected sleep apnea, snoring, or interrupted sleep — these require clinician-evaluated oral appliances, not a sports mouthguard.

Talking with a dentist ensures the right device is chosen and properly fitted for real protection.

Mouthguards for kids, teens, and braces

Kids’ and teens’ mouths change quickly as they grow, which means their mouthguards need to keep up. A well-fitting guard helps protect developing teeth, orthodontic hardware, and soft tissues — especially in sports where contact or falls are common.

Sizing and replacement as kids grow

Because children’s teeth and jaws develop rapidly, their mouthguards often need more frequent replacement than adults. As teeth erupt, shift, or fall out, the guard’s fit can loosen or become uneven — lowering its ability to protect during impact. A mouthguard should be replaced whenever it stops fitting snugly, feels loose, or no longer stays in place during activity.

Sports dentistry discussions consistently emphasize that a guard must allow the child to breathe and speak comfortably.³ Poor fit is a common reason kids stop wearing their mouthguard, so periodic refitting or upgrading to a boil-and-bite or custom option can help.

Specific considerations for braces

Children and teens with braces have a higher risk of soft tissue injuries because brackets and wires can cut the lips and cheeks during a hit. A mouthguard provides a smooth barrier that helps protect both the orthodontic hardware and the inside of the mouth.

Because braces move teeth over time, the fit of a mouthguard may change throughout treatment. Dental organizations recommend selecting a guard that fits comfortably over brackets without restricting movement or placing extra pressure on the hardware. A dentist or orthodontist can help identify options that offer enough room for ongoing tooth movement.

Why a well-fitting guard matters even more with orthodontic hardware

For kids and teens in braces, a well-fitted guard can offer some of the best protection — it helps prevent cuts, bruising, and damage to the dental appliances themselves, which can be costly to repair and may slow down treatment progress. A guard that fits teeth perfectly stays in place, fits smoothly over brackets, and allows normal air circulation supports both safety and comfort.

Because of these factors, families often choose either a properly molded boil-and-bite or a custom-made mouthguard to ensure enough protection, space, and stability during play.

Mouthguard versus night guard: What’s the difference?

A sports mouthguard helps protect teeth and the mouth from impact during sports and other high-risk activities. A night guard helps protect teeth from grinding and clenching, which can wear teeth down or damage dental work over time. They solve different problems — so most people should not swap one for the other.

What each one is designed to protect against

• Sports mouthguard: This guard focuses on impact protection. It usually fits over the upper teeth and helps reduce dental injuries by cushioning blows and protecting soft tissues like lips and cheeks. Dental organizations recommend properly fitted mouthguards for sports and recreational activities with a high risk of dental trauma.

• Night guard: This guard focuses on grinding and clenching (often during sleep). Dentists recommend it to help protect teeth from the pressure and friction of bruxism and to reduce damage related to clenching forces. This device targets a different type of stress than a sports impact.

Why a night guard is not a safe substitute for sports

A night guard is not designed to handle the kind of sudden, high-force impact that can happen during sports. A sports mouthguard needs to stay secure during movement, cushion blows, and protect soft tissues during contact. That design goal differs from a night guard, which focuses on managing long, repeated teeth grinding forces during sleep.

Simply put — wearing a night guard in a sport can leave someone under protected because the device may not provide the right coverage, retention, or impact cushioning for that situation. People who play contact, collision, or fall risk sports should use a mouthguard designed for sports.

Why are dentists pushing night guards?

It’s understandable to feel skeptical — especially when a night guard feels like an extra cost or an extra step. Most dentists recommend these dental mouthguards for a simple reason — they often see the results of teeth grinding and clenching up close, like worn enamel, cracks, jaw soreness, or damage to fillings and crowns. A night guard is a way to prevent teeth grinding and reduce ongoing wear and stress.

Dentists also know that people do not always notice they grind their teeth — especially at night — until damage shows up during a visit at the dental office. That's why many dental teams recommend a night guard when they see clear signs of grinding or when someone reports symptoms like morning jaw tightness or headaches.

A helpful way to think about it: A sports mouthguard is like a seatbelt for sudden events — it protects during a hit. A night guard is more like a protective cover — it helps limit slow, repeated wear. If you're unsure, a dentist can assess and recommend the proper device.

What are the negatives of mouthguards? (and how to avoid them)

Most mouthguard problems come down to fit, comfort, or care. The good news is that each issue can have a simple fix — and many are avoidable with the right type of guard and regular maintenance.

1. Bulky or hard to breathe → adjust the fit or consider custom

• Problem: Some mouthguards, especially stock versions, can feel bulky or make it hard to breathe or talk.

• Fix: Try a boil-and-bite option and follow molding instructions carefully so the material shapes more closely to the teeth. These are made from thermoplastic material that molds to the wearer's teeth. If you still can’t speak or breathe comfortably, a custom mouthguard made by a dentist usually offers the most secure, natural feeling fit.

2. Odor or discoloration → clean, dry, and store in a ventilated case

• Problem: Mouthguards can develop odors, discoloration, or a sticky feel when not cleaned regularly.

• Fix: Rinse the guard before and after each use, brush it gently, let it dry fully, and store it in a vented plastic case rather than a closed container. These steps help prevent bacterial buildup and keep the guard fresher longer.

3. Sore spots or irritation → stop and see a dentist for adjustment

• Problem: If a mouthguard rubs the gums or creates sore spots, it may be too tight, uneven, or poorly molded.

• Fix: Stop using the guard and bring it to a dentist. They can adjust the fit or recommend a different style. This is especially important for athletes with braces or changing bite patterns, who may benefit from a custom-fitted mouthguard.

4. Cavity risk or gum irritation → improve hygiene and stay consistent with dental visits

• Problem: A mouthguard that stays damp, uncleaned, or coated in plaque can irritate the gums or increase cavity risk.

• Fix: For proper care, clean the mouthguard daily, keep up with regular dental checkups, and replace the mouthguard when it becomes worn, misshapen, or difficult to clean. Dentists may also recommend avoiding hot water or direct sunlight, which can warp the material.

Most negatives come from a poor fit or inconsistent cleaning — both of which are easy to fix with the right type of guard and basic care habits.

How to fit a boil-and-bite mouthguard (quick steps)

Boil-and-bite mouthguards are popular because they offer a more personalized fit than stock mouthguards. Here’s a simple, step-by-step way to fit one at home to create your own custom mouthguard, based on typical manufacturer and dental guidance.

1. Soften in hot (not boiling) water: Heat water until it’s hot but not boiling to avoid extreme heat. Place the mouthguard in the water for the time specified in the instructions, so the material softens without losing its structure. Carefully remove it with tongs or a spoon and let it cool just enough so it won’t burn your mouth from the high temperatures.

2. Seat on upper teeth and mold with fingers and tongue: Place the softened mouthguard onto the upper teeth, pressing it firmly with your fingers against the front and sides of the teeth — rather than using your bottom teeth. Use your tongue and gentle suction to help create a snug shape. This step helps the guard follow the natural curves of your bite.

3. Bite gently to set; cool to lock the shape: Bite down lightly to help the guard form around the chewing surfaces. Avoid biting too hard — that can make the guard too thin in spots. Once it's molded, place it briefly in cool water to set the shape. After cooling, check that it stays in place comfortably and allows normal breathing and speaking.

A well-molded boil-and-bite mouthguard should feel snug, stay in place, and allow easy breathing. If it feels loose, uneven, or uncomfortable, you can often remold — or consider upgrading to a custom dental guard that can be designed specifically for your unique needs.

How to clean and store a mouthguard (and when to replace)

Keeping a mouthguard clean and well maintained helps it last longer and protect your teeth. Proper care also reduces bacteria buildup, odor, and wear. Here’s how to handle daily care, deeper cleaning, storage, and replacement timing.

Daily rinse and gentle brushing (avoid hot water)

• Daily care: After each use, rinse the mouthguard with cool or lukewarm water. Use a soft toothbrush and mild soap or toothpaste to gently clean the surface.

• Avoid hot water: Hot or boiling water can warp the material, making the guard lose its shape. This reduces comfort and protection.

Weekly deep clean

For a more thorough cleaning, follow weekly instructions recommended by your dentist or the manufacturer. This may include soaking the guard in a nonalcohol-based cleanser or a denture safe cleaning solution.

Deep cleaning helps prevent odor, discoloration, and bacterial buildup — issues that become more noticeable with frequent use.

Dry fully and store in a ventilated case

After cleaning, let the mouthguard air dry completely. Moisture trapped inside a closed container can encourage bacteria and mold growth. Store the dry mouthguard in a ventilated case so air can circulate. This keeps it fresher and helps the material last longer.

When to replace a mouthguard

Mouthguards don’t last forever. Plan to replace yours when you notice any of the following:

• Cracks or tears in the material.

• Warping or a noticeable change in shape.

• Persistent odor even after cleaning.

• Fit changes — especially common for kids and teens with growing mouths.

• After every sports season or sooner if you take frequent impacts.

A worn or ill-fitting mouthguard cannot provide full protection. Regular dental checkups are a good time to have a dentist examine the guard and confirm whether it’s still safe to use.

Cost and coverage: what to expect

Prices for mouthguards vary widely based on the type, level of customization, and who makes them. Costs generally fall into three tiers — stock, boil-and-bite, and custom — with custom mouthguards being the most precise and the most expensive. Understanding these ranges can help you choose the right level of protection for your needs.^4,5

Understanding coverage differences

Insurance coverage for mouthguards varies significantly by plan. Some dental plans may cover night guards when medically necessary (grinding or TMJ-related issues), but coverage for sports mouthguards is less common. Policies may require documentation or a letter of medical necessity for reimbursement.⁹

Because benefits differ across employers and insurers, the best approach is to:

• Check your plan’s summary of benefits for mouthguard or oral appliance coverage.

• Ask your dental provider’s office whether they can submit the appropriate billing codes.

• Confirm whether your plan covers custom guards, night guards, or both — and whether deductibles or copays apply.

Guardian has partnered with Smile Brilliant to offer dental members cost-effective dental wellness products, including mouthguards.¹⁰ Costs can vary, but what stays consistent is the value: A well-fitted mouthguard protects against injuries that cost far more to treat than the guard itself.¹¹