A dentist was getting ready to clean an elderly lady's teeth. He noticed that she was a little nervous, so he began to tell her a story as he was putting on his surgical gloves...
"Do you know how they make these rubber gloves?"
She said, "No?"
"Well," he spoofed, "down in Mexico they have this big building set up with a large tank of latex, and the workers are all picked according to hand size. Each individual walks up to the tank, dips their hands in, and then walk around for a bit while the latex sets up and dries right onto their hands! Then they peel off the gloves and throw them into the big 'Finished Goods Crate' and start the process all over again."
And she didn't laugh a bit!
Five minutes later, during the procedure, he had to stop cleaning her teeth because she burst out laughing.
The old woman blushed and exclaimed, "I just suddenly thought about how they must make condoms."