Dental anesthetic nerve damage – What is the cause?
Nerve damage after administering dental anesthetic is a known risk factor, although it is very uncommon. Temporary paresthesia is much more common than anything permanent. Since the vast majority of cases go away on their own the reported rate of dental anesthetic nerve damage is likely much higher than reported. There are three theories on the cause of nerve injury.
- Direct trauma to the nerve from the needle itself.
- Intra-neural hematoma formation.
- Local anesthetic toxicity.
Which dental anesthetics are more likely to cause nerve damage?
It appears that the higher percentage anesthetics can cause local anesthetic toxicity that results in dental anesthetic nerve damage. The approximate rate at which it happens overall is around 1:785,000. Such a low rate makes it difficult to study directly.
Pogrel JADA 1995 found no correlation between using lidocaine, prilocaine, and mepivacaine. There was a correlation between dental anesthetic nerve damage and the number of times patient was injected. Although this could result from more chances for physical injury and/or higher doses. A correlation was also found with the patient reporting a feeling of an electric shock, which is a sign the nerve is being injured by needle. Finally, a correlation was found for those that had dental work requiring local anesthetic in that area recently.
Pogrel 2000 found prilocaine more likely to have caused dental anesthetic nerve damage.
Again in 2007 Pogrel found prilocaine to be far more likely to cause nerve damage than articaine or lidocaine.
Garisto 2010 found dental anesthetics with higher concentration were more likely to cause dental anesthetic nerve damage. The main two anesthetics in the study are articaine and prilocaine. Prilocaine was 7x more likely to cause damage and articaine was 3.5x more likely. Others have found similar results, such as Haas 1995 and Gaffen 2009.