We use a toothbrush to remove plaque, an invisible bacterial biofilm, from the mouth. However, if the brush itself becomes contaminated, it cannot effectively perform this function. Studies have shown that after 3-4 months of use, a toothbrush reaches the end of its useful life and becomes less effective at cleaning tooth surfaces. With regular use, the bristles wear down, becoming more susceptible to microbial growth, which can lead to gum disease, often manifested by bleeding gums. Using a toothbrush beyond its recommended lifespan may result in bad breath, as a new toothbrush removes more dental plaque than one with worn-out bristles. After each use, rinse the toothbrush thoroughly with tap water and allow it to dry in open air. Avoid storing it in a closed container, as this encourages bacterial growth and spread.