Toothbrushing plays an important everyday role for personal oral hygiene and effective plaque removal. Appropriate toothbrush care and maintenance are also important considerations for sound oral hygiene. The ADA recommends that consumers replace toothbrushes approximately every 3–4 months or sooner if the bristles become frayed with use.
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 microorganisms, 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 to 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.