I dont best dentist but one of the best jokes I heard on them was

The dentist goes to a bar and starts flirting with a lady. They get cuddly and heads to his appartment. Next day he wakes up and finds her going through his photos..and tell him " I guess u must be a real good dentist". With pride he says yes and ask her how did she know. "Cos I didnt feel a thing yesterday"!!