the number of things growing on your toothbrush is definitely non zero but being frequently scrubbed in sodium fluoride probably inhibits a good portion of it\

related though, electronic toothbrushes are way, way better in terms of tooth care, and my understanding the last time I read through marketing bullshit a few years ago was that the rotational/mechanical ones were better than the ones that just vibrate i.e. Oral B vs Sonicare, but the fucking Oral B toothbrush heads have fucking exposed bits of the mechanism, like, there's these holes in it, so like, guess what? mold grows in there

I don't understand how that isn't like, you know, a massive design flaw that should be changed immediately, but I guess they want people to swap toothbrushes more often than mold would grow, idk