Many years ago, I had a dentist who myself, and many friends who went to him, called "Joe the Butcher". He put me under gas one time and asked me "Ok Pat, are you hearing echoes-echoes-echoes..." He died of a heart attack one day, after lunch, in one of his dental chairs, under the nitrous mask. We all cheered, but sadly it took me over 20 years to find a competent dentist again.