How risky is sharing a toothbrush?

Once you get past the initial ick-factor of toothbrush sharing, it's worth considering whether there are any actual harms. Whether we like it or not, our mouths are home to a unique microbiome. As Norman and Tegan explain, it's influenced by what we eat, who we kiss – and yes, who we might share a toothbrush with. References Armed to the Teeth—The Oral Mucosa Immunity System and Microbiota Assessment of Microbial Contamination of a Toothbrush Head with and without a Protective Cover: An Ex Vivo Study