I wouldn't call stray toothpaste "damage."
Just wipe it off with a damp cloth.
LF drivers are very robust. It's just a paper (or poly, or whetver) cone.
I usually test the excursion of my drivers when I get new ones, and break-in the surrounds a bit, by pumping them to their limits with my hand.
Very hard to cause physical damage to them unless you have something sharp, pointy, or a sudden furious blow.
Dome tweeters are a little more tricky because they have a tendancy to collapse or fold, but can usually be coaxed out somehow (eg by a vaccuum) and shouldn't sound any different even if this has occured.
