Should Toothbrushes be Sterilized?

After an illness such as the cold or flu, should you sterilize your toothbrush?  Does the bacteria remain in the bristles only to reinfect yourself after you’ve recovered?  If so, how does someone perform this sterilization process at home?  Or would it be more convenient to simply discard the old brush and replace with a new one?

Researchers know that the mouth  may harbor microorganisms that could cause oral and/or systemic infection.  It is not surprising that some of these microorganisms are transferred to the brush during use.  Although there is insufficient evidence to support that bacterial growth on toothbrushes will lead to specific illnesses, some concerns regarding cross-contamination will still arise.  

The general design of a toothbrush itself tends to trap bacteria.  The handles have grooves and pits that retain microorganisms.  The bristles are tightly packed tufts of plastic that delay drying and promote bacterial growth.  Other factors contributing to problems with cleaning are repeated exposure to aerosols of all types (bathroom sprays/splatters and organism aerosols generated by toilet flushing).

So what can you do?  Using an antibacterial mouthrinse (before brushing and for soaking toothbrushes) may prevent or decrease the number of bacteria build up on brushes.  Discard your brush after an illness or use disposable brushes during the illness.  A simple and successful disinfection method would be to use your dishwasher, placing the brush with bristle head up in the utensil rack. Operate the washer on regular cycle, including the drying cycle.   A study showed:

• reduced bacterial loads of up to 4 million organisms per toothbrush to less than 50
• removed visible debris from bristle tufts, neck and grooves in handles
• did not cause visible damage to the brush (did not include brushes for electric  brushes)

An unsuccessful attempt at sterilization was the use of a microwave oven.  At 1 or 3 minutes, very little bacteria was killed.  At 10 minutes, a moderate amount of bacteria was reduced, however  the toothbrush melted.  Also, the microwave did not generate even heating, leaving “cool spots” where the organisms survived the process. 

There are commercially available toothbrush sanitizers on the market  that advertise ultraviolet (UV) light disinfection.  In order to kill bacteria, the UV light must be able  reach the organism; however with the tightly packed tufts of bristles, the light may not reach down to the depth of the bristle.  Research has shown that these sanitizers may not provide a specific health benefit; however, if a consumer wishes to purchase  these devices, select a product that has been cleared by the FDA (data was provided to  substantiate their claims).  Also keep in mind that “sterilized” indicates that all living organisms have been destroyed or inactivated.  No commercially available toothbrush cleaning device has been shown to sterilize toothbrushes.  “Sanitizing” normally means the bacteria has been reduced by 99.9%.  Other devices may use steam or dry heat to clean toothbrushes.  Also available are soaking solutions that reduce the bacterial count. 

After an illness, discarding your brush may be more convenient than trying to “sanitize” it.  However, using your dishwasher may be the most successful, simple way to disinfect your toothbrush.  As a Glendale cosmetic dentist, Dr. Wilcox provides a new brush, floss and toothpaste to each patient after a cleaning appointment.  Check the Desert Smiles website to find more on toothbrush care.

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