Microbiological tests on toothbrushes: disinfection and storage methods

Abstract

Toothbrushes, despite being simple and widely used tools, can also pose a risk of disease transmission. To minimize this risk, it is essential to adopt effective methods of toothbrush storage and disinfection. This study aimed to evaluate the available disinfection methods for toothbrushes and identify the safest storage practices. Method: This research is quantitative, cross-sectional, exploratory and prospective. Eight adult toothbrushes were analyzed, which were contaminated and stored in different ways and disinfected with different agents. The contamination assessment was performed by seeding in culture media (Brain Heart Infusion - BHI, Blood Agar, Sabouraud Agar, Baird Parker Agar and Eosin Methylene Blue - EMB), with subsequent analysis of the turbidity of the BHI vials using a spectrophotometer. Results: From the microbiological analysis, two results were obtained. The first was related to the storage media, which, according to the spectrophotometer, showed that the toothbrushes stored in bags and cases presented a higher degree of turbidity, which indicates a higher bacterial concentration and greater contamination, while the toothbrushes stored with a lid in a closed environment obtained the best results with less contamination and consequent turbidity of the medium. All plates showed bacterial and/or fungal growth. The second result is related to disinfection, which, according to the spectrophotometer, seemed to be more effective with 0.12% chlorhexidine, by means of friction. Conclusion: The best practice for storing toothbrushes seems to be the use of protective lids in closed environments, such as drawers or cabinets. Among the disinfectant agents evaluated, 0.12% chlorhexidine demonstrated the greatest effectiveness in reducing bacterial contamination.