@GettingCooked well, they can scavenge toothpaste and toothbrushes just like anything else, the show just doesn't get too into the details of the mundane toilet aspects. granted, they probably wouldn't have that super bright white "fresh from the hygienicist" look, but its not unrealistic in the world of the show. as I recall, for example, at one point they were on a scavenging mission specifically for either diapers or baby formula, forget which