Ask an Expert: Changing Toothbrushes

Dental and Oral Health (Adults)

Changing Toothbrushes
11/25/2009

Question:

I was always told to change my toothbrush after I have a cold of flu because it can make me sick again. But once we get sick our bodies build up antibodies against that flu so we never get the same flu twice. So how can the toothbrush make me sick again. Can you explain this to me?

Answer:

Great question! The American Dental Association (ADA) addresses your question on their website. I have placed the most direct answer to your question in bold print below and pasted the remainder of the informaion for your information. If you have any further questions, please do not hesitate to write again.

"In recent years, scientists have studied whether toothbrushes may harbor microorganisms that could cause oral and/or systemic infection^{1, 2, 3, 4}. We know that the oral cavity is home to hundreds of different types of microorganisms⁵, therefore, it is not surprising that some of these microorganisms are transferred to a toothbrush during use.

It may also be possible for microorganisms that are present in the environment where the toothbrush is stored to establish themselves on the brush. Toothbrushes may even have bacteria on them right out of the box⁴ since they are not required to be sold in a sterile package.

The human body is constantly exposed to potentially harmful microbes. However, the body is normally able defend itself against infections through a combination of passive and active mechanisms. Intact skin and mucous membranes function as a passive barrier to bacteria and other organisms. When these barriers are challenged or breached, active mechanisms such as enzymes, digestive acids, tears, white blood cells and antibodies come into play to protect the body from disease.

Although studies have shown that various microorganisms can grow on toothbrushes after use, and other studies have examined various methods to reduce the level of these bacteria^{6, 7, 8, 9, 10}, there is insufficient clinical evidence to support that bacterial growth on toothbrushes will lead to specific adverse oral or systemic health effects. Although there is insufficient clinical evidence to support that bacterial growth on toothbrushes will lead to specific adverse oral or systemic health effects, a common-sense approach is recommended for situations where patients may be at higher risk to infection or re-infection by various microbes. Examples may include situations where a patient or family member:

Has a systemic disease that may be transmissible by blood or saliva;
Has a compromised immune system or low resistance to infection due to disease, chemotherapy, radiation treatment, etc."

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Response by:

Susan Bauchmoyer, RDH, EFDA, MS
Associate Professor – Clinical, Clinic Director
College of Dentistry
The Ohio State University