Can anesthesia fail to work?

Yes, in rare cases anesthesia does not work well. It can be less effective 1) when severe inflammation has made the tissue acidic, 2) in people who drink frequently or have taken painkillers or sleeping pills long term, and 3) in areas of dense bone such as the lower molars. In those cases we give additional anesthetic or change the technique, and we begin treatment only after confirming the area is fully numb. If you feel pain during treatment, do not endure it - raise your hand and let us know right away.