The Dentist:

A guy goes to a female dentist to have a tooth extracted. 
She pulls out a numbing needle to give the man a shot.
"No way! No needles. I hate needles" the patient said.
The dentist starts to hook up the nitrous oxide and the man says: " I can't do the gas thing. The thought of having the gas mask on suffocates me!'
The dentist then asks the patient if he has any objections to taking a pill.
"No objection," he says. "I'm fine with pills."
The dentist gives him a couple of pills. He swallows them. "What are they?" he says. 
"Viagra," says the dentist.
"Heck," the patient says, "I didn't know Viagra worked as a pain killer."
"It doesn't" said the dentist, "But it will give you something to hold on to when I pull your tooth."