A quantitative approach to the effectiveness of ozone against microbiota organisms colonizing toothbrushes

Toothbrushes are rapidly contaminated with different microorganisms, which colonize the oral cavity and interdental spaces. This can represent a possible cause of infection or reinfection. In this study, the ozone experimental effect upon toothbrushes microflora was estimated microbiologically before and after saturation with ozone gas.

Fifty used toothbrushes coming from children and adults were entered our study. Microorganisms were enumerated and identified. Bristles from each brush were soaked in ozone saturated PBS solution for 5, 10, 15, 20 and 30 min and the total microbial population was reassessed.

Counts of microorganisms isolated per brush varied between 10(2) and 10(7) CFU. Candida albicans was present in used toothbrushes. No obligate anaerobes were isolated. Members of Streptococcaceae family were regularly found (65.2%) belonging to the following species: Streptococcus pyogenes, S. mutans, S. mitis, S. oralis, S. sobrinus, S. viridans, S. salivarius, S. sanguis, Aerococcus viridans. A. viridans and S. mutans were more frequently isolated on children toothbrushes while Staphylococcus aureus and S. epidermidis were found on adults brushes. Escherichia coli, Pseudomonas sp. and Enterococcus sp., were also recovered. We found that the ozone treatment decreased gradually the microbial load. However, a bacterial re-growth was effective following short ozonation period. Decontamination was complete after an extended exposure to ozone for 30 min.

Ozone application was found to remove the toothbrushes bristles microbiota following conventional brushing. Maximum decontamination efficacy of ozone treatment was observed after 30 min while exposure for short time periods seems to be inefficient which probably reflect the low dose of ozone used in this study.