Daily cleaning isn’t optional — it’s classified as a Category A recommendation in the Strength of Recommendation Taxonomy (SORT) evidence system, meaning it’s backed by consistent, high-quality research. The reason is straightforward: mouthguards, like dentures, have a high degree of porosity, creating an ideal habitat for microorganisms. Bacteria infiltrate these pores with each use, and studies have identified a diverse array of pathogens on athletic mouthguards — including Staphylococcus aureus, Streptococcus mutans, various yeasts, and molds linked to conditions ranging from oral infections to exercise-induced asthma.

The cleaning method matters significantly. Research published in BMC Oral Health found that mechanical cleaning with a soft-bristled toothbrush and fluoride toothpaste achieved 98% bacterial removal, while simple water rinsing removed only 60-70%. That’s a substantial difference in protection. Commercial mouthguard cleaners have also proven effective at reducing microbial contamination and biofilm formation.

What many athletes overlook is the storage case. Studies show that storage cases exhibit significant bacterial contamination, including robust biofilm-forming species — often environmental bacteria introduced through improper handling rather than the oral microbiota. The case requires the same attention as the guard itself.

For proper storage, both the mouthguard and case should be thoroughly dried before closing. Moisture promotes bacterial growth. Use a ventilated case that allows air circulation, and store it somewhere clean — not loose in a gym bag where it can pick up environmental contaminants. Athletes should also inspect the guard daily for fit, damage, tears, or loss of resilience, as surface deterioration from regular use dramatically increases bacterial attachment.