WHAT DENTISTS LAUGH AT

A man went to the dental surgeon to have a tooth pulled.
The dentist pulls out a freezing needle to give the man. No way! No
needles! I hate needles!" the patient said.
The dentist starts to hook up the laughing gas and the man again objects. I can't do the gas thing - the thought of having the gas mask on is suffocating to me!"
The dentist then asks if the man has any objection to taking a pill.
No,"-
the patient says, "I am fine with pills".
The dentist then returns and says, "Here is a Viagra tablet."
The patient says, "Wow - I didn't know Viagra worked as a pain pill!"
It doesn't,"- said the dentist -"but it will give you something to hold
onto when I pull your tooth out..