Cleaning · Fundamentals

How to Clean a Mouthguard Without Ruining the Fit

Daily rinse, weekly deep clean, and the four cleaning methods that destroy a custom mouthguard. Plus how to handle smell, discolouration, and the case-rot problem most athletes do not realise they have.

By The GumGear Team7 min read
Mouthguard care kit — soap, brush, and case

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.

10 secDaily rinse
5 minWeekly deep clean
Cool waterOnly safe temperature
Mild soapBest cleaning agent

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.

Daily rinse (every session)

  1. Run cool water over the guard for 10–15 seconds, scrubbing gently with your fingers to clear saliva and debris.
  2. Pat dry with a clean towel.
  3. Leave the guard open on a clean surface — case lid open — for at least 15 minutes before storing.
  4. 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

  1. Rinse with cool water.
  2. Apply a pea-sized amount of mild liquid soap (unscented hand soap or dish soap works) to a soft toothbrush.
  3. Brush every surface for 30–45 seconds — outside, inside, biting surfaces, and the lingual side that contacts the tongue.
  4. Rinse thoroughly until no soap residue remains. Soap residue is what produces that "weird taste" the next time you put the guard in.
  5. 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:

  1. Dissolve a single non-foaming, alcohol-free denture-cleaning tablet in a cup of cool water (not warm — even "warm" tap is too hot).
  2. Drop the guard in for the time specified on the tablet packaging — usually 10–15 minutes.
  3. 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

  1. 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.
  2. 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.
  3. Toothpaste. Abrasive particles in toothpaste scratch the EVA surface. The scratches hold bacteria and accelerate yellowing.
  4. UV sterilisers and boiling sterilisation. Both work on plastics that are not EVA. Yours is. Do not.

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.

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 at around 130°F. 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.

The full daily / weekly / monthly routine — including storage rules, the smell problem, and the two-guard rotation — is in mouthguard care, cleaning & replacement.

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