All the dentists I have known wear face masks for the same reason that bank robbers do, except for Grant Brodie. He doesn't have to. His charges are very modest and in inverse proportion to his dental skills.
We've just been for one tooth extraction (which required two needles), one complete tooth rebuild ("This won't take long", he said, and it did not), and two gum-and-teeth clean-ups, including a tube of GC Tooth Mousse worth $29.45, and at $300 it barely registered on my VISA card.
If after those Easter eggs, you need to see a dentist, see the "Brodie Bunch" in Ulladulla. We can't wait for our next appointment in October.