Why do dental hygienists have to wear face masks to do teeth work?

so they don't get your spit and crap from your mouth in their eyeballs.Why do dental hygienists have to wear face masks to do teeth work?
your geek breath!Why do dental hygienists have to wear face masks to do teeth work?
So that if the person they're working on suddenly starts choking the hygienist doesn't get sputum spit in their face, which could go into their mouth, eyes, and get into their skin and if the person they're working on has Hepatitis (or any other contagious condition) they will be less likely to contract it.
The mouth is the number one place for germs to breeed, it is warm and moist and germs love that so when a hygenist cleans your teeth all those germs fly out your mouth and could possibly end up in their mouth or on their face and they coudl transfer it into there mouth...for the same reason people who work in kitchens wear caps on their hair....to stop germs from spreading!
Do you want someone's spit, plaque, blood and old food particles in YOUR mouth?
To protect themselves from germs. Your mouth is filled with bacteria and stuff flies out!
becasue there are germs in the human mouth that can enter into the doctors body by the breath.so he wears a mask to eliminate the germs