How much bacteria does your electric toothbrush hold?

Hollow-head electric toothbrushes may hold 3,000 times more bacteria than solid-head toothbrushes.

According to recent research conducted at the University of Texas Health Science Center at Houston (UTHealth) School of Dentistry, solid head power toothbrushes may be better for our health than hollow-head toothbrushes. Results from the study, which was published in the Journal of Dental Hygiene, demonstrated that bacteria growth in hollow-head electric toothbrushes was significantly higher than those with solid heads. Indeed, it was established that the hollow-head bacteria growth was up to 3,000 times higher.

Over a period of three weeks participants were required to use one of three randomly allocated electric toothbrushes to clean teeth twice a day. Flossing practices were continued throughout the study and participants were instructed to use non-antimicrobial toothpaste and were to refrain from using other dental products such as mouthwash.

Throughout the duration of the study toothbrush heads were exposed to five types of oral microorganisms: oral streptococci and oral enterococcus anaerobes, yeast and mould, Porphyromonas gingivalis, anaerobes and facultative microorganisms, and Fusobacterium species. At the study’s conclusion toothbrush heads were tested by lead study author Donna Warren-Morris and colleagues.

Results from the study revealed that there were higher microbial counts in the two hollow-head toothbrush groups compared to the solid-head toothbrush group in 9 out of 10 comparisons. If not cleaned and left to dry between uses, it is possible that bacteria may be transferred into the mouth. This can lead to adverse effects on oral health such as tooth decay, bad breath, gingivitis and additional infections and diseases.

The reason behind the higher amounts of bacteria found in hollow-head toothbrushes is believe to be due to the extra surface area in which biofilms have space to form. The solid-head toothbrushes however, have less space in which to permit the growth of bacteria. Researchers involved with the study have suggested that this information could prove particularly important for individuals with weak immune systems.

Unfortunately it can be difficult to recognise the difference between a solid-head and a hollow-head design as the packaging on most electric toothbrushes will not make the distinction between the two. However, the easiest way to determine the type of toothbrush head is to assess the brush heads connection to the electric toothbrush. A solid-head design will have room for the body and head of the toothbrush to connect but a large percent of it should appear solid, whereas the hollow-head design will have excess space or look hollow in the area around the brush bristles.

It was also noted by the researchers responsible for that study that there is no current or published study that validates that the growth of bacteria on toothbrush heads can cause or lead to systemic health effects. However, there are a number of microorganisms that have been linked with systemic diseases.

Helpful suggestions to maintain optimal oral health:

    • Use a toothbrush with soft nylon bristles.
    • Disinfect toothbrushes after each use – some electric toothbrushes have an ultraviolet system included but soaking the head in mouthwash for 20 minutes is just as effective.
    • Leave brushes in a dry environment – bacteria are more likely to grow in the damp.
    • Get a new toothbrush (or head) every 3-4 months.
    • Store brushes in separate holders to avoid cross-contamination.

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Article Source:
The above content is based on materials provided by University of Texas Health Science Center at Houston. Note: Materials have been edited to content and length.

Journal Reference:
Donna W. Morris, et al., “Microbial contamination of power toothbrushes: a comparison of solid-head designs,” Journal of Dental Hygiene 88, No. 4. (2014): 237-242.

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Additionally, LifeCare Dental does not accept liability to any person for the information or advice provided on this website or incorporated into it by reference. Content has been prepared for Western Australian residents and wider Australian audiences, and was accurate at the time of publication. Readers should note that, over time, currency and completeness of the information may change. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions.

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