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Dental Anesthesia

`Immunity` to lidocaine, carbocaine, novocain



I have had a lot of dental work done this year at a dental school. While I feel I get good care, it does take longer and requires more visits.

A couple years ago, I badly cut my hand. The lidocaine injections did not work. When I received an epidural during childbirth (25 years ago), it did not take. General anesthesia has not been a problem.

The dental school gave me carbocaine which seemed to help but only short-term. I had to have multiple injections over a 3-4 hour period. Ultimately, I experience rapid heart-beat, anxiety and shakiness. (Not like me.)

The last couple of times, the carbocaine has not worked. Today, they gave me a huge dosage off carbocaine as they were placing an onlay and then had to give me something that started with an i....caine. This was much better ... albeit short-lived. I was told to expect the effects to last about 10 hours. Within 3 hours, the numbness was gone.

Do you have any suggestions. I still have a cavity and a crown to deal with.

Thank you!


Local anesthetics, while tremendously effective medications, do not work well for everyone. It is not clear which anesthetic was used but it was likely bupivicaine as this causes lip and tongue anesthesia for several hours, although not in your case.

I might suggest articaine, which is a 4% solution rather than a 2% or 3% solution. For lower jaw anesthesia, there is a slight, but measurable, increase in nerve injury over less concentrated solutions but the increase is very slight and some say there is no increase adverse effects.

In your case, the benefits would seem to outweigh the risks, since general anesthesia may be the only good alternative. It is not clear to me why local anesthetics with epinephrine are not used, as the depth and duration of anesthesia is much better. Also, articaine comes in a low-dose epinephrine solution that may help if this is an issue.

Hopefully, there is a dentist anesthesiologist at your dental school who your student dentist can consult on this issue. Discuss this with the student and faculty.

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Response by:

Steven I Ganzberg, SB, DMD, MS Steven I Ganzberg, SB, DMD, MS
Formerly, Clinical Professor of Dentistry
College of Dentistry
The Ohio State University