I ve had neurologic reactions to low doses of local anesthesia 1 2 of a small vial or carbocaine and also epinephrine topically fine with lidocane an alergist advises using gas from now on however i have a root cnal and several deep filing replacements am

Use the Nitrous: Most dentists are skilled at administering nitrous oxide or "laughing gas" . However if you are female make sure you are not pregnant. Two other compounds to talk to your dentist about would be ketamine or propofol. Ketamine can be given im or IV and Propofol can be given iv. Both compounds are used for sedation frequently.

Consult both: Please ask your allergist to talk to your dentist to have some form of anesthesia for the root canal procedure taking into account your allergy.

A safe choice : Would be to have a dentist do the work in a hospital setting with a board certified anesthesiologist. You will be monitored during and after the procedure for complications. One option for you that avoids local use would be to have general anesthesia. Not a common choice for root canal, but maybe appropriate in your case.

Need more info: Carbocaine is in the same class as Lidocaine so if you have a bad reaction to one you should have it with the other. Need to know what your neuro rxn was but its possible it was to the epi (fast heart rate or tinglin in hands or oral/mouth numbness). Allergy to Carbocaine (mepivacaine) or Lidocaine is extremely rare.

Talk to MD: There are alternatives to Carbocaine that can be used in its stead. Talk to dentist and choose treatment that is right for you. The dentist can also talk to an anesthetiologist and choose a local anesthetic that is more suited to your needs. A general anesthetic is of course another alternative. Good luck.