There must have been a time when you did not carry your toothbrush and found it safe to use someone else's. While you're most likely to avoid a stranger's toothbrush, sharing one with your sibling or partner may have seemed harmless. But what if we told you that you've got it all wrong?
In an interaction with the OnlyMyHealth team, Dr Sakshi Hinduja, BDS, Aster CMI Hospital, Bengaluru, sheds light on the health risks associated with sharing toothbrushes – even with your nearest and dearest ones.
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What Germs And Bacteria Can Transfer Through Toothbrushes?
According to Dr Hinduja, a toothbrush can carry germs and bacteria from the mouth if it is not cleaned or stored properly. Common bacteria include:
- Streptococcus and Staphylococcus, which can cause throat or skin infections.
- E. coli and Salmonella that may transfer if the toothbrush touches contaminated surfaces.
- Fungi like Candida, which can cause oral thrush, can also grow on a wet brush.
- Viruses such as the cold, flu, or even herpes that can survive briefly on bristles.
"Sharing toothbrushes increases the risk of transferring these germs between people. Even small amounts of saliva left on the brush can allow bacteria to multiply. Regular rinsing, drying, and replacing your toothbrush every 3–4 months helps reduce this risk," Dr Hinduja adds.
Why Shouldn’t You Share A Toothbrush?
In a 2024 study published in the Clinical Cosmetic and Investigational Dentistry, many students recognised the risks of sharing toothbrushes, with 68.2% identifying it as the most common way infections could spread through a toothbrush. Similarly, earlier research also showed that 86.3% of students believed sharing toothbrushes was the main mode of infection transmission.
Dr Hinduja notes that sharing a toothbrush can spread serious infections because it transfers saliva, blood, and germs from one person to another. She explains, "Bacteria like Streptococcus or Staphylococcus can cause throat, gum, or skin infections. Viruses such as cold, flu, or herpes can also be passed on."
"Blood from gums may carry infections like hepatitis B or other bloodborne germs. Even small cuts or sores in the mouth increase the risk of spreading disease," she adds.
It is important to know that children, the elderly, and people with weak immunity are more vulnerable to serious infections. Sharing a toothbrush also allows fungi like Candida to move between mouths, causing oral thrush. For safety, each person should always use their own toothbrush and store it separately.
Rinsing Does Not Make Things Better
According to Dr Hinduja, rinsing a toothbrush, even under hot water, is not enough to sterilise it because most germs, bacteria, and viruses can survive brief contact with heat.
She explains, "The water from a tap, even if warm, usually does not reach a high enough temperature to kill all microorganisms. Bacteria can hide deep between bristles, where water may not reach effectively. Viruses and fungi can also survive on damp surfaces for hours or days. Even rinsing with soap or mouthwash only reduces germs partially but does not remove them completely."
"Proper cleaning methods, like soaking in an antiseptic solution, using a UV sanitiser, or replacing the toothbrush regularly, are more effective at keeping it safe and reducing the risk of infections," she shares.
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“Couples Who Share Toothbrushes At Greater Health Risk”
If you thought being close to someone, like your partner, is enough to justify sharing a toothbrush, then you're wrong. Dr Hinduja clarifies that even couples who are very close and share many things are at higher health risk if they share toothbrushes.
She says, "Sharing a toothbrush passes saliva, blood, and germs directly between mouths. Bacteria like Streptococcus or Staphylococcus can cause gum or throat infections. Viruses such as cold, flu, or herpes can also be transmitted. Blood in the mouth can carry serious infections like hepatitis B. Even small cuts or sores increase the risk. Fungi like Candida, which can cause oral thrush, can also spread. Close contact does not make the mouth immune to new germs. For safety, each person should always have their own toothbrush and store it separately, even in a loving relationship."
Safest Way To Handle Your Toothbrushes
The safest way to store a toothbrush is:
- To keep it upright in a holder where it can air dry.
- To not touch other toothbrushes to prevent germ transfer.
- To avoid keeping it in a closed container for long periods, as moisture encourages bacteria and fungi to grow.
- To rinse the brush thoroughly after each use to remove toothpaste and debris
- To replace your toothbrush every 3–4 months, or sooner if bristles are frayed or after an illness.
- Using a separate holder for each family member and letting the brush dry completely between uses reduces infection risk.
“Occasionally, you can soak the toothbrush in an antiseptic mouthwash or use a UV sanitiser to keep it extra clean,” Dr Hinduja concludes.