The video is in response to the 'David After Dentist' YouTube entry that has had more than 5,000,000 views (at time of writing post) in just over a week! The video is of a 7 year old boy that has just had his tooth removed at the dentist and is quite clearly "out-of-it". The response simply recreates the same situation with virtually the same dialogue, but because it's Chad Vader the whole thing becomes brilliant. It reminds me of the hilarious 'Charlie Bit My Finger' video that circulated offices a while back and is close to 80,000,000 views!
The original video - David After Dentist:
David After Dentist
The Chad Vader response video:
Chad After Dentist