The simplest way to sanitize a mouth guard is to brush it with mild soap and cool water after every use, then do a deeper soak once a week. A mouth guard sits against your teeth and gums for hours at a time, and researchers have found up to 17 types of potentially harmful bacteria living on used mouth guards and inside their cases. Some of those bacteria are linked to gum disease, tooth decay, and even respiratory infections. A regular cleaning routine keeps that buildup in check.
Quick Clean After Every Use
The American Dental Association recommends rinsing your mouth guard before and after each use, or brushing it with a toothbrush and toothpaste. For a slightly more thorough daily clean, use a soft-bristle toothbrush with a mild, alcohol-free soap. Antibacterial soap, castile soap, or plain dish soap all work. Apply a small amount, gently scrub all surfaces, and rinse thoroughly with cool water until no residue remains.
If you prefer toothpaste, choose a nonabrasive formula. Whitening or gritty toothpastes can scratch the surface of the guard over time, and those tiny grooves become breeding grounds for bacteria. A quick brush takes under a minute and prevents the slimy film that forms when saliva dries on the material overnight.
Deep Cleaning Methods
A weekly deep soak handles the buildup that daily brushing misses. You have several options depending on what you have at home.
Hydrogen Peroxide
Place your mouth guard in a clean glass and pour in enough hydrogen peroxide (the standard 3% bottle from the pharmacy) to fully cover it. Let it soak for 30 minutes, then rinse well with cool water.
White Vinegar
Put the mouth guard in a glass and add enough white vinegar to submerge it. Soak for 30 minutes, then rinse. Vinegar has a strong smell, but it dissipates once you rinse the guard thoroughly.
Baking Soda Paste
Mix equal parts baking soda and water to form a paste. Dip a soft toothbrush into the paste and gently scrub the entire mouth guard. Rinse with cool water. This method works well for removing odors and light staining without submerging the guard in liquid.
Denture Cleaner Tablets
Over-the-counter denture cleaning tablets dissolve in warm water and release a mild bleaching agent. Drop a tablet into a glass of warm (not hot) water, place the mouth guard in the fizzing solution, and soak for 5 to 10 minutes or according to the package directions. These tablets are effective at breaking down biofilm but contain persulfates, which can trigger allergic reactions in some people. If you notice any irritation in your mouth after using a denture cleaner, switch to one of the other methods.
Alcohol-Free Mouthwash
Add a capful of alcohol-free mouthwash to a glass and dilute with water until the mouth guard is fully covered. Soak for 30 minutes, then rinse. The “alcohol-free” part matters, because alcohol-based mouthwash can dry out and degrade the guard’s material over time.
What Not to Use
Most mouth guards are made from EVA (ethylene vinyl acetate), a thermoplastic that softens at temperatures between 80 and 120°C. That’s well above the temperature of hot tap water but easily reached by boiling water, a dishwasher’s heated dry cycle, or leaving the guard on a car dashboard in summer. Heat warps the material and ruins the fit, and a mouth guard that no longer fits your teeth properly won’t protect them.
Avoid alcohol-based products, including regular mouthwash and rubbing alcohol. Alcohol dries and cracks the plastic over time. Full-strength household bleach is also too harsh. Denture tablets contain a diluted form of bleach that’s safe for short soaks, but pouring undiluted bleach on your guard will damage it and leave a residue you don’t want in your mouth. Abrasive cleaners and stiff-bristled brushes scratch the surface, creating microscopic pits where bacteria can hide even after cleaning.
How to Store It Properly
Cleaning the guard thoroughly and then sealing it in a damp, airtight container defeats the purpose. Bacteria thrive in warm, moist environments. After rinsing, let your mouth guard air dry completely on a clean surface before putting it away. Use a ventilated case with holes or slots that allow air circulation. The case itself needs regular cleaning too. Researchers found the same harmful bacteria on the cases as on the mouth guards themselves, so wash the case with soap and water at least once a week and let it dry fully between uses.
Keep the case out of direct sunlight and away from heat sources. A bathroom counter or a gym bag left in a hot car are both poor choices for long-term storage.
When Cleaning Isn’t Enough
Even with consistent care, mouth guards degrade. Replace yours when you notice cracking, thinning, or fraying in the material. These weak spots compromise protection during sports and also create textured surfaces that harbor bacteria no amount of soaking can fully remove. A persistent odor or visible staining that doesn’t respond to deep cleaning is another clear sign. If the guard feels loose or doesn’t sit snugly against your teeth anymore, the fit has changed and it’s time for a new one.
Bring your mouth guard to regular dental checkups. Your dentist can evaluate the fit and condition, and give it a professional cleaning while you’re there. For custom-fitted guards, your dentist can also tell you whether a refit is possible or whether replacement makes more sense.