When I was in the States, I used to go to a dentist on Long Island. He was a good dentist; but, often, his novacane does not really do the numbing job for my teeth (especially the lower teeth) for some reasons. But, the dentist I found in Tokyo can drill my tooth (even the lower tooth) painlessly after one shot of anesthetic. I am just curious to know if there is a different kind of anesthetic in New York and Tokyo? I understand there is a high probability that my experiences could be just anomaly.