Exploring the most efficient way to reduce bacterial colonisation on contaminated toothbrushes

Whisky, microwave or hairdryer? Exploring the most efficient way to reduce bacterial colonisation on contaminated toothbrushes

• R. Patcas
• , R. Zbinden
• , M. Schätzle
• , P. R. Schmidlin
• & M. Zehnder

BDJ volume225, pages1007–1010 (14 December 2018) | Download Citation

Key points

• Toothbrush bristles are crammed with oral and environmental pathogens. Even when left untouched for 24 hours, toothbrushes remain highly contaminated.
  
  
• Hairdryer heat or immersion in whisky cannot disinfect toothbrush bristles satisfactorily within a minute.
  
  
• Microwave oven cooking seems to be an effective technique to overcome bacterial contamination of toothbrushes.
  

Abstract
Aims
It is the holiday season, but your toothbrush does not look very festive. It is damp and has been used and contaminated by someone else. To rectify this heinous crime, this study investigates the effectiveness of three household objects to disinfect toothbrushes.

Design
In-vitro study performed under conditions simulating everyday life.

Materials and methods
Twenty toothbrushes were contaminated using a mixture of saliva and trypticase soy broth containing Escherichia coli and Enterococcus faecalis. These contaminated toothbrushes were submerged in whisky, cooked in a microwave oven, or exposed to the hot air stream of a hairdryer, separately. Each treatment was performed on five toothbrushes for one minute. Untreated specimens (n = 5) served as controls. Toothbrushes were subsequently sonicated in sterile physiological saline, which was plated on selective agars. Bacterial counts were graded as low, medium, or high.

Results
Residual contamination was influenced by the disinfectant applied, both in E. coli (p <0.001) and E. faecalis (p = 0.019). Microwave cooking achieved highest decontamination, while whisky had no significant effect on bacterial counts over no treatment (p = 0.8). Hot air showed some limited effectiveness under current conditions.

Conclusions
Microwave oven cooking appears to be a simple, cheap, and effective way to reduce bacterial contamination of your toothbrush.