Dental trial of carbocaine; a new local anaesthetic.

A RECENT report from Scandinavia (Dhuner et al., 1956) describes a clinical trial of Carbocaine in which 652 cases were injected with results which the authors describe as raising " expectations that Carbocaine may prove to be of great value as a local anaesthetic drug." It was found that, when no adrenaline was used, anaesthesia lasted longer with Carbocaine than with lignocaine (Xylocaine), for i, 1 and 2 per cent solutions. Using adrenaline, anaesthesia lasted longer with lignocaine. However, none of the above cases was for dental operation. This paper describes a trial of the drug in dental cases and gives the results obtained. It is considered that a search for new local anaesthetics is necessary because, although lignocaine is a great improvement on earlier local anaesthetics, clinical experience shows that it does not provide consistently successful anaesthesia. Sherman, Fiasconaro and Chilton (1954) obtained complete elimination of pain in 84 per cent of cases with lignocaine 2 per cent plus epinephrine 1:50,000, and in 88 per cent of cases with lignocaine 2 per cent plus epinephrine 1:100,000. It must be remembered that although Bjorn (1947) and Huldt (1953) obtained 100 per cent success with lignocaine, they worked only on upper lateral incisors and tested anaesthesia by Bjom's (1946) electrical method, not by surgery. Also patients sometimes complain that the injection makes their faces or lips feel swollen, hard, cold, too numb, or that the anaesthesia is " too dense ". Attention has been drawn to this