A preliminary report using oxethazaine--a potential new dental local anaesthetic.

Oxethazaine is the most potent local anaesthetic in use. It is claimed to be 2000 times more potent than lignocaine and 500 times more potent than cocaine as assessed in rabbits eyes. Currently, oxethazaine is used in an antacid preparation for the topical relief of pain in conditions such as hiatus hernia, where the local pH is very low. Since oxethazaine is active in an acidic environment, it was decided to use oxethazaine, in a pilot study of 20 patients requiring minor oral surgery procedures, at a concentration of 0.1% at pH 3, to assess its value in achieving dental local anaesthesia. It was found that the local anaesthesia achieved was sufficient in all patients to allow the operative procedure to proceed. In two of the patients, who presented with acute periapical pathology, satisfactory local anaesthesia was achieved with 0.1% oxethazaine following a failure with lignocaine 2% and 1:80,000 adrenaline. The duration of anaesthesia was found to be similar to the average achieved with lignocaine 2% and 1:80,000 adrenaline.