My dentist back in the 80s didn't even wear gloves, he was an older man but I can't imagine gloves were not required then or even when he would have trained in the 40s or 50s.
Is your opinion based on evidence? Sorry for sounding harsh, the article is about evidence, but your comment seems to be more based on feels / ick / sheen / vibe of squeaky cleanliness.
If it's imagine vs imagine: I imagine that a washed and disinfected hand without open wounds has no measurable risks, and the tactile feedback the dentist gets may improve the treatment.
people with infected, nasty mouths too. ain't just gonna be the routine inspection and flouride treatment, something foul be brewing in some of their faceholes, and now its all over your hands.
