A custom mouthguard takes about ten seconds of care per session and five minutes once a week. Skipping that routine — or using the wrong method — is what cuts a guard's lifespan in half. Here is the cleaning protocol that keeps a $99–$169 guard fitting like day one, and the four methods that destroy it fastest.
The short answer
Rinse with cool water after every session. Brush weekly with a soft toothbrush and mild soap. Air-dry fully before storing. Never use hot water, dishwashers, alcohol-based mouthwash, or toothpaste. That is the entire routine. If it smells, you are storing it damp; if the fit changes, you exposed it to heat.
What you need (and what you don't)
The whole kit costs a few dollars and fits in a drawer. Nothing on this list is specialised.
- A soft toothbrush, used only for the guard. Keep it separate from the one you use on your teeth, and replace it when the bristles splay. A soft brush reaches the bite ridges and edges without scratching.
- Mild liquid soap. Unscented hand soap or a plain dish soap. Strongly perfumed products can leave a taste behind.
- A cup or bowl for cool water. Only needed for the monthly soak.
- A clean towel or a clean, dry shelf to air-dry on.
- Optional: alcohol-free, non-foaming denture tablets for the monthly soak.
What you do not need: a steriliser, a boiling pan, a speciality "mouthguard spray," or anything that smells strongly of mint or alcohol. If a product is built for hot or harsh use, it is wrong for EVA.
What actually builds up on a guard
A guard sits in a warm, wet mouth for an hour or more at a time, then spends the rest of its life in a case. Four things collect on it:
- Saliva and food residue, which dry into a thin film.
- A layer of bacteria, which is what gives you the slimy feel and the smell. This grows fastest when the guard goes into a closed case damp.
- Sweat and skin oils, especially after hard training.
- Stains, from sports drinks, coffee, and dark liquids.
Most of this comes off with cool water, mild soap, and a brush. The goal is not to sterilise the guard — that would need heat or harsh chemicals, which damage it — but to remove the film before it builds up, and to keep the guard dry between uses.
Daily rinse (every session)
- Run cool water over the guard for 10–15 seconds, scrubbing gently with your fingers to clear saliva and debris.
- Pat dry with a clean towel.
- Leave the guard open on a clean surface — case lid open — for at least 15 minutes before storing.
- Place it in the ventilated case to dry the rest of the way.
Closed case + wet guard = bacteria farm. Air-dry first. Every time.
Weekly deep clean
- Rinse with cool water.
- Apply a pea-sized amount of mild liquid soap (unscented hand soap or dish soap works) to a soft toothbrush.
- Brush every surface for 30–45 seconds — outside, inside, biting surfaces, and the lingual side that contacts the tongue.
- Rinse thoroughly until no soap residue remains. Soap residue is what produces that "weird taste" the next time you put the guard in.
- Air-dry on a clean surface for at least 30 minutes before storing.
Monthly disinfecting soak
Once a month, give the guard a deeper disinfection cycle:
- Dissolve a single non-foaming, alcohol-free denture-cleaning tablet in a cup of cool water (not warm — even "warm" tap is too hot).
- Drop the guard in for the time specified on the tablet packaging — usually 10–15 minutes.
- Remove, rinse thoroughly with cool water, and air-dry fully.
Hydrogen peroxide solutions and alcohol-based soaks both degrade EVA over time. Stick with non-alcohol denture tablets if you want a disinfecting step beyond mild soap.
Four methods that destroy a custom guard
- Hot water of any kind. Dishwasher, kettle rinse, "just a warm rinse to get the soap off." All of it warps the guard. The fit dies first; the material dies shortly after.
- Alcohol-based mouthwash as a cleaner. Listerine and similar rinses break down the cross-linked polymer matrix of EVA. Tasteless to you, lethal to the guard.
- Toothpaste. Abrasive particles in toothpaste scratch the EVA surface. The scratches hold bacteria and accelerate yellowing.
- UV sterilisers and boiling sterilisation. Both work on plastics that are not EVA. Yours is. Do not.
What about baking soda, vinegar, and wipes?
Search for how to clean a mouthguard and you will find a long list of household suggestions. We have not tested these on our layered EVA over many cleaning cycles, so we stick to the boring routine above. In the meantime, here is how to think about them:
| Method | Our view | Why |
|---|---|---|
| Cool water and mild soap | Recommended | Effective on film and bacteria, gentle on EVA |
| Alcohol-free denture tablet (monthly) | Fine, occasionally | Adds a disinfecting step without alcohol or heat |
| Baking soda paste | Skip | Gritty, so it can scratch in the same way toothpaste does |
| Diluted vinegar | Skip | Unproven on guards, strong smell, and soap already does the job |
| Bleach or hydrogen peroxide | Avoid | Harsh chemicals that can break down the material |
| Hand sanitiser or alcohol wipes | Avoid | Alcohol is the thing to keep away from EVA |
| Baby wipes and scented wipes | Avoid | Leave a residue and a taste you then put in your mouth |
Mistakes that look harmless
Most damage to a guard comes from well-meant shortcuts rather than obvious abuse. These are the ones we would fix first:
- Rinsing under the warm tap. Warm water can start to soften EVA and change the fit. Run it cold, or cool, every time.
- Wrapping a wet guard in a towel or tissue. It holds the moisture against the surface, and it is how guards end up in the laundry or the bin.
- Only cleaning it when it smells. By the time you can smell it, the film has been building for days. The weekly clean is a prevention step, not a rescue.
- Scrubbing hard. Pressure does not make the guard cleaner. A soft brush and 30–45 seconds with light pressure is enough, and a stiff brush leaves scratches that hold bacteria.
- Soaking overnight. The monthly soak is a timed step that follows the tablet packaging. Leaving the guard in any solution for hours is not stronger, just harder on the material.
- Storing the guard and a damp brush together. The brush needs to dry as well. Keep it where it can air out.
- Closing the case on a guard that is "nearly" dry. Nearly dry is how the next week's smell starts. If you are in a hurry, pat it dry and leave the case open on the bench while you shower.
If you find yourself doing several of these, you have not failed at cleaning. The routine just needs to be easier to follow than the shortcut. Keep the brush, soap, and case in one place, and the weekly clean takes five minutes.
Removing smell and discolouration
If your guard smells after a fresh deep-clean, try one full monthly soak cycle with a non-alcohol denture tablet. If the smell returns within 48 hours, the surface is microscopically scarred (usually from past toothpaste or mouthwash use) and the guard should be replaced — see how long does a mouthguard last.
Light yellowing is normal as EVA ages. Chalky-white discolouration on the inside surface means heat damage — the material has broken down and the fit is compromised whether or not it still feels okay. Replace.
Troubleshooting: what you see and what to do
| What you notice | Likely cause | What to do |
|---|---|---|
| Slimy or tacky feel | Bacterial film from damp storage | Full weekly clean, then dry completely before storing |
| A soapy taste | Soap not fully rinsed | Rinse in cool water until the water runs clear and the taste is gone |
| A white film that wipes off | Dried soap or mineral deposits from hard water | Rinse and brush again, then dry with a clean towel |
| Chalky white that does not wipe off | Heat damage to the material | Cannot be cleaned away; replace the guard |
| Yellow or brown tint | Stains from drinks, or normal ageing | Wash promptly after dark drinks; light yellowing is cosmetic |
| Sour smell that returns within 48 hours | Surface scratched or damaged | Replace the guard |
| Rough texture | Abrasion from toothpaste or a stiff brush | Switch to a soft brush and soap; roughness will not smooth out |
After blood, illness, drinks, and salt water
Some days call for more than the standard rinse.
- After blood or a cut mouth. Rinse with cool water straight away, before anything dries on the guard, then do a full soap clean before the next session. Keep it out of a closed case until it is completely dry. Use cool water only; hot water is the wrong move here too.
- After being ill. When you are back to normal, give the guard a full soap clean and wash the case as well. If you have a spare guard, rotate to it for a few days while the first one dries and airs.
- After sports drinks, coffee, or alcohol. Rinse before the sugars and dyes dry on. A guard worn in a club or at a party is no exception; a cool rinse is enough most of the time.
- After a dive. Rinse a scuba mouthpiece in fresh water to remove salt, then air-dry. Salt left to dry on the surface is a source of long-term wear. More on diving specifics in the custom scuba mouthpiece guide.
- For kids. Parents should supervise the weekly clean for younger children. Cool water and soap are safe for everyone; the part that needs checking is the air-dry step, which children skip most often.
Cleaning the case
The case needs cleaning too. Bacteria, sweat, and dried saliva accumulate inside the ventilated case and re-colonise the guard each time you put it away. Wash the case with mild soap and water once a week (same day as your weekly guard deep clean), let it air-dry overnight, and replace the case once a year regardless of how it looks. GumGear ships a fresh case with every new guard.
Travel and gym-bag rules
- Never wet in a closed bag. Always air-dry before storing, including before zipping a gym bag.
- Never on a car dashboard. The dash hits 120–160°F in summer. EVA softens well below the boiling point of water. The fit dies in one afternoon.
- Airline travel: carry-on only. Cargo holds drop below freezing and rise above 100°F on the same flight. Keep the case in your carry-on.
- Long-haul: rinse on arrival. Plane air is dry and the case develops static-cling debris. Rinse the guard before first use after a long flight.
How to tell it is actually clean
Cleanliness is easy to check with your senses. A clean guard:
- has no smell once it is dry, or only a faint plastic note;
- feels smooth and slightly dry rather than slick or tacky;
- has no visible film in the grooves of the bite surface;
- does not leave a taste when you first put it in.
If a full clean does not get you there and the smell is back within 48 hours, the cause is the guard, not your cleaning. The next step is to check whether it has reached the end of its life, which is covered in how long does a mouthguard last.
If you are noticing gum soreness, a sore patch, or an unusual taste that persists even when the guard is clean, that is a reason to see a dentist rather than clean harder.
The full daily / weekly / monthly routine — including storage rules, the smell problem, and the two-guard rotation — is in mouthguard care, cleaning & replacement.
