Pulpal anesthesia efficacy of four lidocaine solutions injected with an intraligamentary syringe.

Four lidocaine solutions that differed in concentration or vasoconstrictor composition were compared for efficacy of pulpal anesthesia. These drugs were injected in a double-blind manner with the use of an intraligamentary syringe to the periodontal ligament of maxillary lateral incisors. These teeth were subjected to electric pulp test stimulation that yielded absolute sensation threshold values. It was found that there was no dose response relationship between the local anesthetic concentration and the efficacy of pulpal anesthesia. Lidocaine 2% with vasopressin 25 IU% and noradrenaline bitartrate produced a noticeably shorter duration of pulpal anesthesia in comparison with the other three drugs. The results indicated that the nature of vasoconstrictors when added to the local anesthetic can affect the efficacy of pulpal anesthesia using the intraligamentary model.