Efficacy of liposome-encapsulated 0.5% ropivacaine in maxillary dental anaesthesia

The aim of this study was to evaluate the effectiveness of liposome-encapsulated ropivacaine (0.5%) in dental anaesthesia. This randomised, double-blind, crossover, four-period treatment study included 40 volunteers who were given 1.8 ml of the following local anaesthetics into the buccal sulcus at the right level of the upper canine: 0.5% ropivacaine; 0.5% ropivacaine with 1:200,000 adrenaline; liposome-encapsulated 0.5% ropivacaine; and 2% lignocaine with 1:100,000 adrenaline. Onset of pulpal anaesthesia; the success of anaesthesia; and the duration of labial, gingival, and pulpal anaesthesia involving the upper right canine and first premolar were evaluated. At the end of each injection, volunteers rated the pain on injection on a visual analogue scale (VAS). Both ropivacaine and adrenaline, and lignocaine with adrenaline, were more successful anaesthetic agents than liposome-encapsulated ropivacaine or plain ropivacaine (p < 0.05). There were no significant differences among the anaesthetic preparations in the onset of pulpal anaesthesia. Ropivacaine and adrenaline and lignocaine and adrenaline gave a significantly longer duration of pulpal anaesthesia. VAS showed no significant differences among the groups tested. The results showed that encapsulation of liposome did not improve the anaesthetic efficacy of ropivacaine.