Subject: dentists
The dentist pulls out a numbing needle to give the man a shot.
“No way. No needles. I hate needles.” the patient says.
The dentist starts to hook up the nitrous oxide and the man objects.
“I can’t do the gas thing. The thought of having the gas mask on is suffocating me.”
The dentist then asks the patient if he has any objection to taking a pill.
“No objection,” the patient says, “I’m fine with pills.”
The dentist then hands him a pill and a glass of water and says, “Here’s a Viagra.”
The patient says, “Wow, I didn’t know Viagra worked as a pain killer.”
“It doesn’t,” said the dentist, “but it’s going to give you something to hold on to when I pull your tooth.”
Boadicea's Chariot 
Oooh, the mind boggles just thinking about it!
Love it, can you hear me laughing 🙂
Heh, heh. Just stole it and sent it to my son – he has to have a root canal filling 😦