If you throw your toothbrush in the trash every time you get sick, it may be unnecessary: Toothbrushes you use while you have strep or a sore throat don’t continue to harbour the germs you had while sick, according to a new UTMB study presented at the Pediatric Academic Societies. While these findings suggest it’s probably safe to keep your toothbrush even if you’ve used it while sick, there are other times when it’s best to say bye to your brush. The main one: If it’s been three months since your last switch, it’s time to grab a new brush.