Aspiration Prior to Injection

Aspiration should always be performed prior to injection of any local anaesthetic solution. The toxic effect of both local anaesthetic and vasoconstrictor are increased where they are injected intravenously, so aspiration should always be performed prior to injection.

Inadvertent intravenous injection may occur not only with mandibular and maxillary block injections, but also in infiltration of both facial and palatal sites. An adequate aspirating syringe with a needle no finer than 26 gauge should be used for all injections and at least 2 seconds should be allowed for the aspiration.