Liposome-encapsulated ropivacaine for intraoral topical anesthesia.

OBJECTIVES

This study evaluated the efficacy of liposome-encapsulated 2% ropivacaine in topical anesthesia and its influence on pulpal response.

STUDY

DESIGN

Forty volunteers received the following topical formulations in the buccal fold of the maxillary lateral incisors region (bilaterally): liposome-encapsulated 2% ropivacaine gel (RL2); 20% benzocaine gel (B20); liposomal placebo gel (LP); and placebo gel (P). Formulations were kept in place for 30 minutes, during which time the teeth were electric pulp tested every 10 minutes. After this procedure, a dental needle was inserted until periosteum contact in the same site of topical application and pain was rated by a visual analog scale. Duration of soft tissue anesthesia was assessed by pinprick test.

RESULTS

RL2 and B20 showed lower pain response to needle insertion and longer soft tissue anesthesia then P and LP (P = .0003 and P < .0001, respectively); however, RL2 was not different from B20 (P > .05) regarding those parameters. None of the formulations was able to induce pulpal anesthesia.

CONCLUSION

RL2 was as effective as B20 in reducing pain during needle insertion and inducing soft tissue anesthesia; however, neither one was able to induce pulpal anesthesia after a 30-min application.