Most dental personnel are on some kind of amphetamine. Meth, dex, oct, hyp, it matters naught to them, they use them to get out of bed in the morning.
Also, anesthetic only works properly in seven cases out of ten. The other three range from semi-numb/conscious to internally alert, but externally unresponsive. You feel the pain, but cannot cry out.
Finally, the bacteria and germs that live in the average human mouth have already evolved defences against modern antibiotics, so even with those god-awful pills they make you swallow, your jaw is still likely to get infected